Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2017	Oct. 31, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	Piedmont Office Realty Trust, Inc.
Entity Central Index Key	0001042776
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		144,371,942

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets:
Land	$ 614,934	$ 617,138
Buildings and improvements, less accumulated depreciation of $926,105 and $856,254 as of September 30, 2017 and December 31, 2016, respectively	2,723,163	2,754,106
Intangible lease assets, less accumulated amortization of $93,265 and $109,152 as of September 30, 2017 and December 31, 2016, respectively	78,700	99,695
Construction in progress	8,957	34,814
Real estate assets held for sale, net	0	225,939
Total real estate assets	3,425,754	3,731,692
Investments in and amounts due from unconsolidated joint ventures	49	7,360
Cash and cash equivalents	36,108	6,992
Tenant receivables, net of allowance for doubtful accounts of $535 and $197 as of September 30, 2017 and December 31, 2016, respectively	12,802	26,494
Straight-line rent receivables	182,609	163,789
Restricted cash and escrows	1,260	1,212
Prepaid expenses and other assets	28,232	23,201
Goodwill	98,918	98,918
Interest rate swaps	34	0
Deferred lease costs, less accumulated amortization of $189,469 and $175,643 as of September 30, 2017 and December 31, 2016, respectively	274,884	298,695
Other assets held for sale, net	0	9,815
Total assets	4,060,650	4,368,168
Liabilities:
Unsecured debt, net of discount and unamortized debt issuance costs of $8,337 and $10,269 as of September 30, 2017 and December 31, 2016, respectively	1,511,663	1,687,731
Secured debt, net of premiums and unamortized debt issuance costs of $1,020 and $1,161 as of September 30, 2017 and December 31, 2016, respectively	191,923	332,744
Accounts payable, accrued expenses, and accrued capital expenditures	108,120	165,410
Deferred income	29,970	28,406
Intangible lease liabilities, less accumulated amortization of $54,637 and $49,225 as of September 30, 2017 and December 31, 2016, respectively	41,064	48,005
Interest rate swaps	3,915	8,169
Total liabilities	1,886,655	2,270,465
Commitments and Contingencies
Stockholders’ Equity:
Shares-in-trust, 150,000,000 shares authorized; none outstanding as of September 30, 2017 or December 31, 2016	0	0
Preferred stock, no par value, 100,000,000 shares authorized; none outstanding as of September 30, 2017 or December 31, 2016	0	0
Common stock, $.01 par value, 750,000,000 shares authorized; 145,294,845 and 145,235,313 shares issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	1,453	1,452
Additional paid-in capital	3,676,706	3,673,128
Cumulative distributions in excess of earnings	(1,511,428)	(1,580,863)
Other comprehensive income	5,400	2,104
Piedmont stockholders’ equity	2,172,131	2,095,821
Noncontrolling interest	1,864	1,882
Total stockholders’ equity	2,173,995	2,097,703
Total liabilities and stockholders’ equity	$ 4,060,650	$ 4,368,168

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets:
Intangible lease assets, accumulated amortization	$ 93,265	$ 109,152
Tenant receivables, allowance for doubtful accounts	535	197
Deferred lease costs, accumulated amortization	189,469	175,643
Liabilities:
Intangible lease liabilities, accumulated amortization	$ 54,637	$ 49,225
Stockholders’ Equity:
Shares-in-trust, shares authorized (in shares)	150,000,000	150,000,000
Shares-in-trust, shares outstanding (in shares)	0	0
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares issued (in shares)	145,294,845	145,235,313
Common stock, shares outstanding (in shares)	145,294,845	145,235,313
Unsecured Debt
Liabilities:
Discount, (premiums) and unamortized debt issuance costs	$ 8,337	$ 10,269
Secured Debt
Liabilities:
Discount, (premiums) and unamortized debt issuance costs	(1,020)	(1,161)
Building and improvements
Assets:
Buildings and improvements, accumulated depreciation	$ 926,105	$ 856,254

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Rental income	$ 113,350	$ 113,821	$ 361,048	$ 340,326
Tenant reimbursements	23,796	24,163	72,340	70,000
Property management fee revenue	441	501	1,341	1,478
Total revenues	137,587	138,485	434,729	411,804
Expenses:
Property operating costs	54,090	54,867	165,253	161,438
Depreciation	30,000	31,610	90,827	94,948
Amortization	18,123	18,640	57,852	53,848
Impairment loss on real estate assets	0	22,951	0	33,901
General and administrative	6,618	7,429	23,250	23,518
Operating expenses	108,831	135,497	337,182	367,653
Real estate operating income	28,756	2,988	97,547	44,151
Other income (expense):
Interest expense	(16,183)	(15,496)	(52,661)	(48,294)
Other income/(expense)	290	(720)	228	(467)
Net recoveries from casualty events	0	34	0	34
Equity in income of unconsolidated joint ventures	3,754	129	3,872	354
Other income (expense)	(12,139)	(16,053)	(48,561)	(48,373)
Income/(loss) from continuing operations	16,617	(13,065)	48,986	(4,222)
Discontinued operations:
Operating income	0	1	0	0
Income from discontinued operations	0	1	0	0
Gain/(loss) on sale of real estate assets, net	109,512	(57)	115,951	73,758
Net income/(loss)	126,129	(13,121)	164,937	69,536
Plus: Net income applicable to noncontrolling interest	4	14	10	7
Net income/(loss) applicable to Piedmont	$ 126,133	$ (13,107)	$ 164,947	$ 69,543
Per share information – basic and diluted:
Income/(loss) from continuing operations and gain/(loss) on sale of real estate assets (in dollars per share)	$ 0.87	$ (0.09)	$ 1.13	$ 0.48
Income from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00
Net income applicable to common stockholders (in dollars per share)	$ 0.87	$ (0.09)	$ 1.13	$ 0.48
Weighted-average common shares outstanding – basic (in shares)	145,415,678	145,231,160	145,372,182	145,228,755
Weighted-average common shares outstanding – diluted (in shares)	145,719,431	145,669,237	145,679,582	145,601,026

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income/(loss) applicable to Piedmont	$ 126,133	$ (13,107)	$ 164,947	$ 69,543
Other comprehensive income/(loss):
Effective portion of gain/(loss) on derivative instruments that are designated and qualify as cash flow hedges (See Note 5)	175	2,847	307	(12,182)
Plus: Reclassification of previously recorded loss included in net income (See Note 5)	653	1,045	2,936	3,291
Gain on investment in available for sale securities	25	7	53	19
Other comprehensive income/(loss)	853	3,899	3,296	(8,872)
Comprehensive income/(loss) applicable to Piedmont	$ 126,986	$ (9,208)	$ 168,243	$ 60,671

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Cumulative Distributions in Excess of Earnings	Other Comprehensive Income/(Loss)	Non- controlling Interest
Balance at Dec. 31, 2015	$ 2,123,420	$ 1,455	$ 3,669,977	$ (1,550,698)	$ 1,661	$ 1,025
Balance (in shares) at Dec. 31, 2015		145,512,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income applicable to noncontrolling interest	(7)
Net income applicable to Piedmont	69,543
Other comprehensive income	$ (8,872)
Balance (in shares) at Sep. 30, 2016	145,234,000
Balance at Dec. 31, 2015	$ 2,123,420	$ 1,455	3,669,977	(1,550,698)	1,661	1,025
Balance (in shares) at Dec. 31, 2015		145,512,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share repurchases as part of an announced plan	(7,943)	$ (5)		(7,938)
Share repurchases as part of an announced plan (in shares)		(462,000)
Offering costs	(342)		(342)
Noncontrolling interest in consolidated joint venture	888		0			888
Dividends to common stockholders ($0.84 (YTD 2016) and $0.63 (YTD 2017) per share), dividends to stockholders of subsidiary, and dividends reinvested	(122,148)		(173)	(121,959)		(16)
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax	3,668	$ 2	3,666
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax (in shares)		185,000
Net income applicable to noncontrolling interest	(15)					(15)
Net income applicable to Piedmont	99,732			99,732
Other comprehensive income	443				443
Balance at Dec. 31, 2016	$ 2,097,703	$ 1,452	3,673,128	(1,580,863)	2,104	1,882
Balance (in shares) at Dec. 31, 2016	145,235,313	145,235,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share repurchases as part of an announced plan	$ (3,895)	$ (2)		(3,893)
Share repurchases as part of an announced plan (in shares)		(195,000)
Offering costs	(97)		(97)
Dividends to common stockholders ($0.84 (YTD 2016) and $0.63 (YTD 2017) per share), dividends to stockholders of subsidiary, and dividends reinvested	(91,706)		(79)	(91,619)		(8)
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax	3,757	$ 3	3,754
Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax (in shares)		255,000
Net income applicable to noncontrolling interest	(10)					(10)
Net income applicable to Piedmont	164,947			164,947
Other comprehensive income	3,296				3,296
Balance at Sep. 30, 2017	$ 2,173,995	$ 1,453	$ 3,676,706	$ (1,511,428)	$ 5,400	$ 1,864
Balance (in shares) at Sep. 30, 2017	145,294,845	145,295,000

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 164,937	$ 69,536
Operating distributions received from unconsolidated joint ventures	0	579
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	90,827	94,948
Amortization of debt issuance costs	1,214	1,264
Other amortization	57,146	53,325
Impairment loss on real estate assets	0	33,901
Stock compensation expense	6,657	7,630
Equity in income of unconsolidated joint ventures	(3,872)	(354)
Gain on sale of real estate assets, net	(115,951)	(73,758)
Changes in assets and liabilities:
Decrease in tenant and straight-line rent receivables, net	(15,040)	(17,393)
(Increase)/decrease in restricted cash and escrows	(656)	3,451
Increase in prepaid expenses and other assets	(4,580)	(3,429)
(Decrease)/increase in accounts payable and accrued expenses	(5,863)	307
Decrease in deferred income	1,513	2,029
Net cash provided by operating activities	176,332	172,036
Cash Flows from Investing Activities:
Acquisition of real estate assets, related intangibles, and cash held in escrow for acquisitions	0	(66,900)
Capitalized expenditures, net of accruals	(65,407)	(88,391)
Investment in consolidated joint venture	0	(165,848)
Net sales proceeds from wholly-owned properties	375,199	304,902
Net sales proceeds from unconsolidated joint ventures	12,334	0
Investments in unconsolidated joint ventures	(1,162)	0
Deferred lease costs paid	(19,419)	(15,345)
Net cash provided by/(used in) investing activities	301,545	(31,582)
Cash Flows from Financing Activities:
Debt issuance costs paid	(101)	(212)
Proceeds from debt	147,000	552,000
Repayments of debt	(466,046)	(589,532)
Costs of issuance of common stock	(97)	(239)
Value of shares withheld to pay tax obligations related to employee stock compensation	(3,385)	(2,328)
Repurchases of common stock as part of announced plan	(3,895)	(7,943)
Dividends paid and discount on dividend reinvestments	(122,237)	(91,609)
Net cash used in financing activities	(448,761)	(139,863)
Net increase in cash and cash equivalents	29,116	591
Cash and cash equivalents, beginning of period	6,992	5,441
Cash and cash equivalents, end of period	36,108	6,032
Supplemental Disclosures of Significant Noncash Investing and Financing Activities:
Accrued dividends and discount on dividend reinvestments	(30,531)	0
Accrued capital expenditures and deferred lease costs	8,590	24,624
Investment in consolidated joint venture	$ 63,026	$ 0

Organization	9 Months Ended
Organization	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Piedmont Office Realty Trust, Inc. (“Piedmont”) (NYSE: PDM) is a Maryland corporation that operates in a manner so as to qualify as a real estate investment trust (“REIT”) for federal income tax purposes and engages in the acquisition, development, management, and ownership of commercial real estate properties throughout the United States, including properties that are under construction, are newly constructed, or have operating histories. Piedmont was incorporated in 1997 and commenced operations in 1998. Piedmont conducts business primarily through Piedmont Operating Partnership, L.P. (“Piedmont OP”), a Delaware limited partnership, as well as performing the management of its buildings through two wholly-owned subsidiaries, Piedmont Government Services, LLC and Piedmont Office Management, LLC. Piedmont owns 99.9% of, and is the sole general partner of, Piedmont OP and as such, possesses full legal control and authority over the operations of Piedmont OP. The remaining 0.1% ownership interest of Piedmont OP is held indirectly by Piedmont through its wholly-owned subsidiary, Piedmont Office Holdings, Inc. ("POH"), the sole limited partner of Piedmont OP. Piedmont OP owns properties directly, through wholly-owned subsidiaries, and through consolidated joint ventures. References to Piedmont herein shall include Piedmont and all of its subsidiaries, including Piedmont OP and its subsidiaries and joint ventures. As of September 30, 2017, Piedmont owned 66 in-service office properties. Piedmont's total consolidated portfolio consists of approximately 19 million square feet of primarily Class A commercial office space, and was 89.2% leased as of September 30, 2017. As of September 30, 2017, approximately 88% of Piedmont's ALR was generated from select sub-markets located primarily within eight major office markets located in the Eastern-half of the United States: Atlanta, Boston, Chicago, Dallas, Minneapolis, New York, Orlando, and Washington, D.C. Piedmont internally evaluates all of its real estate assets as one operating segment, and accordingly, does not report segment information.

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The consolidated financial statements of Piedmont have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”), including the instructions to Form 10-Q and Article 10 of Regulation S-X, and do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair presentation of the results for such periods. Results for these interim periods are not necessarily indicative of a full year’s results. Piedmont’s consolidated financial statements include the accounts of Piedmont, Piedmont’s wholly-owned subsidiaries, any variable interest entity ("VIE") for which Piedmont or any of its wholly-owned subsidiaries is considered to have the power to direct the activities of the entity and the obligation to absorb losses/right to receive benefits, or any entity in which Piedmont or any of its wholly-owned subsidiaries owns a controlling interest. In determining whether Piedmont or Piedmont OP has a controlling interest, the following factors, among others, are considered: equity ownership, voting rights, protective rights of investors, and participatory rights of investors. For further information, refer to the financial statements and footnotes included in Piedmont’s Amended Annual Report on Form 10-K/A for the year ended December 31, 2016. All intercompany balances and transactions have been eliminated upon consolidation. Further, Piedmont has formed special purpose entities to acquire and hold real estate. Each special purpose entity is a separate legal entity. Consequently, the assets of these special purpose entities are not available to all creditors of Piedmont. The assets owned by these special purpose entities are being reported on a consolidated basis with Piedmont’s assets for financial reporting purposes only. Use of Estimates The preparation of the accompanying consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and notes. Actual results could differ from those estimates. Income Taxes Piedmont has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended, and has operated as such, beginning with its taxable year ended December 31, 1998. To qualify as a REIT, Piedmont must meet certain organizational and operational requirements, including a requirement to distribute at least 90% of its annual REIT taxable income. As a REIT, Piedmont is generally not subject to federal income taxes, subject to fulfilling, among other things, this distribution requirement. Piedmont is subject to certain taxes related to the operations of properties in certain locations, as well as operations conducted by its taxable REIT subsidiary, POH, which have been provided for in the financial statements. Reclassifications Certain prior period amounts presented in Piedmont's Amended Annual Report on Form 10-K/A for the year ended December 31, 2016 have been reclassified to conform to the current period financial statement presentation. The reclassifications relate to the Two Independence Square building, located in Washington, D.C., which was first classified as held for sale as of March 31, 2017, and was sold on July 5, 2017. Applicable balances related to the same asset remain classified as held for sale as of December 31, 2016. Recent Accounting Pronouncements The Financial Accounting Standards Board (the "FASB") has issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09") and Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606) Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08"). The amendments in ASU 2014-09, which are further clarified in ASU 2016-08, as well as Accounting Standards Update 2016-10, Accounting Standards Update 2016-12, and Accounting Standards Update 2016-20 (collectively the "Revenue Recognition Amendments"), change the criteria for the recognition of certain revenue streams to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services using a five-step determination process. Steps 1 through 5 involve (i) identifying contracts with a customer, (ii) identifying the performance obligations in the contract, (iii) determining the transaction price, (iv) allocating the transaction price to the performance obligations, and (v) recognizing revenue as an entity satisfies a performance obligation. The revenues impacted by the Revenue Recognition Amendments include a portion of Piedmont's tenant reimbursement revenues and property management fee revenues. Lease contracts and reimbursement revenues associated with property taxes and insurance are specifically excluded from the Revenue Recognition Amendments. The Revenue Recognition Amendments are effective in the first quarter of 2018 for Piedmont. Management has substantially completed its initial assessment of the impact of adoption of the Revenue Recognition Amendments. Approximately 90% of Piedmont's total revenues are derived from either long-term leases with its tenants or reimbursement of property tax and insurance expenses, which are excluded from the scope of the Revenue Recognition Amendments. In addition, based on management's assessment to date, Piedmont does not expect the timing of the recognition of reimbursement revenue and revenue from management agreements to change as a result of the new guidance, though certain classifications will change between rental revenue and tenant reimbursements. Finally, management has determined, and the FASB has confirmed, that the evaluation of non-lease components under the new Revenue Recognition Amendments will not be effective until Accounting Standards Update No. 2016-02, Leases (Topic 842), ("ASU 2016-02") becomes effective (see further discussion below), which will be first quarter of 2019 for Piedmont. Although management continues to evaluate the guidance and disclosures required by the Revenue Recognition Amendments, Piedmont does not anticipate any material impact to its consolidated financial statements as a result of adoption. The FASB has issued Accounting Standards Update No. 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets ("ASU 2017-05"). The provisions of ASU 2017-05 define the term "in substance nonfinancial asset" as a financial asset promised to a counterparty in a contract if substantially all of the fair value of the assets (recognized and unrecognized) is concentrated in nonfinancial assets. Further, it states that nonfinancial assets should be derecognized once the counterparty obtains control. Finally, the amendments provide clarification for partial sales of nonfinancial assets. ASU 2017-05 is effective concurrent with the Revenue Recognition Amendments (detailed above), which will be the first quarter of 2018 for Piedmont. Although management continues to evaluate the guidance and disclosures required by ASU 2017-05, Piedmont does not anticipate a material change in how it recognizes, measures, and classifies the gain or loss on the disposition of real estate in its consolidated financial statements as a result of adoption. The FASB has issued Accounting Standards Update No. 2016-01, Financial Instruments - Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). The amendments in ASU 2016-01 require equity investments, except those accounted for under the equity method of accounting, to be measured at estimated fair value with changes in fair value recognized in net income. Additionally, ASU 2016-01 simplifies the impairment assessment of equity investments, and eliminates certain disclosure requirements. The amendments in ASU 2016-01 are effective in the first quarter of 2018, and Piedmont does not anticipate any material impact to its consolidated financial statements as a result of adoption. The FASB has issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash (a consensus of the FASB Emerging Issues Task Force) ("ASU 2016-18"). The provisions of ASU 2016-18 require entities to show changes in restricted cash and cash equivalents in addition to cash and cash equivalents in the statement of cash flows. As a result, entities will no longer present transfers between restricted and unrestricted cash in the statement of cash flows. Disclosures are required to reconcile the amount presented on the statement of cash flows to the balance sheet, as well as disclosing the nature of restriction on the restricted cash balances. ASU 2016-18 is effective for Piedmont in the first quarter of 2018, with early adoption permitted. Piedmont does not anticipate any material impact to its consolidated financial statements as a result of adoption. The FASB has issued ASU 2016-02, which fundamentally changes the definition of a lease, as well as the accounting for operating leases by requiring lessees to recognize assets and liabilities which arise from the lease, consisting of a liability to make lease payments (the lease liability) and a right-of-use asset, representing the right to use the leased asset over the term of the lease. Accounting for leases by lessors is substantially unchanged from prior practice as lessors will continue to recognize lease revenue on a straight-line basis; however, ASU 2016-02 defines certain tenant reimbursements as non-lease components which will be subject to the guidance under ASU 2014-09. The amendments in ASU 2016-02 are effective in the first quarter of 2019, and Piedmont is currently evaluating the potential impact of adoption. The FASB has issued Accounting Standards Update No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). The provisions of ASU 2016-13 replace the "incurred loss" approach with an "expected loss" model for impairing trade and other receivables, held-to-maturity debt securities, net investment in leases, and off-balance-sheet credit exposures, which will generally result in earlier recognition of allowances for credit losses. Additionally, the provisions change the classification of credit losses related to available-for-sale securities to an allowance, rather than a direct reduction of the amortized cost of the securities. ASU 2016-13 is effective in the first quarter of 2020, with early adoption permitted as of January 1, 2019. Piedmont is currently evaluating the potential impact of adoption. The FASB has issued Accounting Standards Update No. 2017-04, Intangibles—Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment ("ASU 2017-04"). The provisions of ASU 2017-04 simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test, which is generally performed annually unless events or circumstances arise which would necessitate evaluating the carrying value for impairment in the interim. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a entity’s goodwill with the carrying amount of that goodwill by determining the fair value of its assets and liabilities (including unrecognized assets and liabilities) following the procedures that would be required in a business combination. Under the provisions of ASU 2017-04, an entity would instead recognize an impairment charge for the amount by which the carrying amount exceeds the entity’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that entity. ASU 2017-04 is effective in the first quarter of 2020, with early adoption permitted as of the first interim or annual impairment test of goodwill after January 1, 2017. Piedmont is currently evaluating the potential impact of adoption.

Debt

9 Months Ended

Sep. 30, 2017

Debt Disclosure [Abstract]

Debt

During the three months ended September 30, 2017, Piedmont fully repaid the $140 Million WDC Fixed-Rate Loans prior to the maturity date without penalty and repaid the outstanding balance of the $500 Million Unsecured 2015 Line of Credit, using a portion of the net proceeds from the sale of the Two Independence Square building (see Note 9).

The following table summarizes the terms of Piedmont’s indebtedness outstanding as of September 30, 2017 and December 31, 2016 (in thousands):



Facility ⁽¹⁾	Stated Rate		Effective Rate ⁽²⁾			Maturity		Amount Outstanding as of
Facility ⁽¹⁾	Stated Rate		Effective Rate ⁽²⁾			Maturity		September 30, 2017		December 31, 2016
Secured (Fixed)
$140 Million WDC Fixed-Rate Loans	5.76	%	5.76	%		11/1/2017		$	—	$	140,000
$35 Million Fixed-Rate Loan ⁽³⁾	5.55	%	3.75	%		9/1/2021		30,903		31,583
$160 Million Fixed-Rate Loan ⁽⁴⁾	3.48	%	3.58	%		7/5/2022		160,000		160,000
Net premium and unamortized debt issuance costs								1,020		1,161
Subtotal/Weighted Average ⁽⁵⁾	3.82	%						191,923		332,744
Unsecured (Variable and Fixed)
$170 Million Unsecured 2015 Term Loan ⁽⁶⁾	LIBOR + 1.125%		2.37	%		5/15/2018		170,000		170,000
$300 Million Unsecured 2013 Term Loan	LIBOR + 1.20%		2.78	%	⁽⁷⁾	1/31/2019		300,000		300,000
$500 Million Unsecured 2015 Line of Credit ⁽⁶⁾	LIBOR + 1.00%		—	%		6/18/2019	⁽⁸⁾	—		178,000
$300 Million Unsecured 2011 Term Loan	LIBOR + 1.15%		3.35	%	⁽⁷⁾	1/15/2020		300,000		300,000
$350 Million Senior Notes	3.40	%	3.43	%		6/01/2023		350,000		350,000
$400 Million Senior Notes	4.45	%	4.10	%		3/15/2024		400,000		400,000
Discounts and unamortized debt issuance costs								(8,337)		(10,269)
Subtotal/Weighted Average ⁽⁵⁾	3.43	%						1,511,663		1,687,731
Total/Weighted Average ⁽⁵⁾	3.47	%						$	1,703,586	$	2,020,475


⁽¹⁾	Other than the $35 Million Fixed-Rate Loan, all of Piedmont’s outstanding debt as of September 30, 2017 and December 31, 2016 is interest-only.


⁽²⁾	Effective rate after consideration of settled or in-place interest rate swap agreements, issuance premiums/discounts, and/or fair market value adjustments upon assumption of debt.


⁽³⁾	Collateralized by the 5 Wall Street building in Burlington, Massachusetts.


⁽⁴⁾	Collateralized by the 1901 Market Street building in Philadelphia, Pennsylvania.


⁽⁵⁾	Weighted average is based on contractual balance of outstanding debt and the stated or effectively fixed interest rates in the table as of September 30, 2017.


⁽⁶⁾	On a periodic basis, Piedmont may select from multiple interest rate options, including the prime rate and various-length LIBOR locks. All LIBOR selections are subject to an additional spread over the selected rate based on Piedmont’s current credit rating.


⁽⁷⁾	Facility has a stated variable rate; however, Piedmont has entered into interest rate swap agreements which effectively fix, exclusive of Piedmont's credit rating, the rate shown as the effective rate.


⁽⁸⁾	Piedmont may extend the term for up to one additional year (through two available six month extensions to a final extended maturity date of June 18, 2020) provided Piedmont is not then in default and upon payment of extension fees.

Piedmont made interest payments on all debt facilities, including interest rate swap cash settlements, of approximately $18.0 million and $18.5 million for the three months ended September 30, 2017 and 2016, respectively, and approximately $54.0 million and $53.2 million for the nine months ended September 30, 2017 and 2016, respectively. Also, Piedmont capitalized interest of approximately $37,000 and $1.5 million for the three months ended September 30, 2017 and 2016, respectively, and approximately $0.2 million and $3.4 million for the nine months ended September 30, 2017 and 2016, respectively. As of September 30, 2017, Piedmont believes it was in compliance with all financial covenants associated with its debt instruments. See Note 6 for a description of Piedmont’s estimated fair value of debt as of September 30, 2017.

Variable Interest Entities

9 Months Ended

Sep. 30, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Variable Interest Entities

Variable interest holders who have the power to direct the activities of the VIE that most significantly impact the entity’s economic performance and have the obligation to absorb the majority of losses of the entity or the right to receive significant benefits of the entity must consolidate the VIE. Each of the following VIEs has the sole purpose of holding land and office buildings and their resulting operations, and are classified in the accompanying consolidated balance sheets in the same manner as Piedmont’s wholly-owned properties.

A summary of Piedmont’s interests in, and consolidation treatment of, its VIEs and their related carrying values as of September 30, 2017 and December 31, 2016 is as follows (net carrying amount in millions):



Entity	Piedmont’s % Ownership of Entity		Related Building	Consolidated/ Unconsolidated	Net Carrying Amount as of September 30, 2017		Net Carrying Amount as of December 31, 2016			Primary Beneficiary Considerations
1201 Eye Street N.W. Associates, LLC	98.6%	⁽¹⁾	1201 Eye Street	Consolidated	$	82.1	$	(6.7	)	In accordance with the partnership’s governing documents, Piedmont currently receives 100% of the cash flow of the entity and has sole discretion in directing the management and leasing activities of the building.
1225 Eye Street N.W. Associates, LLC	98.1%	⁽¹⁾	1225 Eye Street	Consolidated	$	66.2	$	9.9		In accordance with the partnership’s governing documents, Piedmont currently receives 100% of the cash flow of the entity and has sole discretion in directing the management and leasing activities of the building.
Piedmont 500 W. Monroe Fee, LLC	100%		500 W. Monroe	Consolidated	$	265.2	$	262.4		The Omnibus Agreement with the previous owner includes equity participation rights for the previous owner, if certain financial returns are achieved; however, Piedmont has sole decision making authority and is entitled to 100% of the economic benefits of the property until such returns are met.

⁽¹⁾During the three months ended September 30, 2017, Piedmont repaid a $140 million mortgage secured by the 1201 and 1225 Eye Street properties located in Washington, D.C., and recapitalized the 1201 and 1225 Eye Street N.W. Associates, LLCs, increasing Piedmont's ownership from 49.5% in each of the LLCs to the amounts stated above.

Derivative Instruments

9 Months Ended

Sep. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Instruments

Risk Management Objective of Using Derivatives

In addition to operational risks which arise in the normal course of business, Piedmont is exposed to economic risks such as interest rate, liquidity, and credit risk. In certain situations, Piedmont has entered into derivative financial instruments such as interest rate swap agreements and other similar agreements to manage interest rate risk exposure arising from current or future variable rate debt transactions. Interest rate swap agreements involve the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. Piedmont’s objective in using interest rate derivatives is to add stability to interest expense and to manage its exposure to interest rate movements.

Cash Flow Hedges of Interest Rate Risk

Interest rate swaps designated as cash flow hedges involve the receipt of variable-rate amounts from a counterparty in exchange for Piedmont making fixed-rate payments over the life of the agreements without changing the underlying notional amount. As of September 30, 2017, Piedmont was party to various interest rate swap agreements, all of which are designated as effective cash flow hedges and fully hedge the variable cash flows covering the entire outstanding balances of the $300 Million Unsecured 2011 Term Loan and the $300 Million Unsecured 2013 Term Loan. The maximum length of time over which Piedmont is hedging its exposure to the variability in future cash flows for forecasted transactions is 27 months.

A detail of Piedmont’s interest rate derivatives outstanding as of September 30, 2017 is as follows:

Interest Rate Derivatives:

Number of Swap Agreements

Associated Debt Instrument

Total Notional Amount

(in millions)

Effective Date

Maturity Date

Interest rate swaps

$300 Million Unsecured 2013 Term Loan

200

1/30/2014

1/31/2019

Interest rate swaps

$300 Million Unsecured 2013 Term Loan

100

8/29/2014

1/31/2019

Interest rate swaps

$300 Million Unsecured 2011 Term Loan

300

11/22/2016

1/15/2020

Total

600

Piedmont presents its interest rate derivatives on its consolidated balance sheets on a gross basis as interest rate swap assets and interest rate swap liabilities. A detail of Piedmont’s interest rate derivatives on a gross and net basis as of September 30, 2017 and December 31, 2016, respectively, is as follows (in thousands):



Interest rate swaps classified as:	September 30, 2017			December 31, 2016
Gross derivative assets	$	34		$	—
Gross derivative liabilities	(3,915		)	(8,169		)
Net derivative asset/(liability)	$	(3,881	)	$	(8,169	)

The effective portion of Piedmont's interest rate derivatives, including the gain/(loss) on previously settled forward swaps, that was recorded in the accompanying consolidated statements of income for the three and nine months ended September 30, 2017 and 2016, respectively, was as follows (in thousands):



	Three Months Ended				Nine Months Ended
Interest Rate Swaps in Cash Flow Hedging Relationships	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Amount of gain/(loss) recognized in OCI	$	175	$	2,847	$	307	$	(12,182	)
Amount of previously recorded loss reclassified from accumulated OCI into interest expense	$	653	$	1,045	$	2,936	$	3,291

Piedmont estimates that approximately $1.2 million will be reclassified from accumulated other comprehensive loss to interest expense over the next twelve months. Piedmont recognized no loss related to hedge ineffectiveness of its cash flow hedges during the three and nine months ended September 30, 2017 and 2016, respectively.

Additionally, see Note 6 for fair value disclosures of Piedmont's derivative instruments.

Credit-risk-related Contingent Features

Piedmont has agreements with its derivative counterparties that contain a provision whereby if Piedmont defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then Piedmont could also be declared in default on its derivative obligations. If Piedmont were to breach any of the contractual provisions of the derivative contracts, it could be required to settle its obligations under the agreements at their termination value of the estimated fair values plus accrued interest, or approximately $4.0 million as of September 30, 2017. Additionally, Piedmont has rights of set-off under certain of its derivative agreements related to potential termination fees and amounts payable under the agreements, if a termination were to occur.

- Definition

The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts.

+ References

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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/presentationRef
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Reference 9: http://www.xbrl.org/2003/role/presentationRef
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 16: http://www.xbrl.org/2003/role/presentationRef
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Reference 19: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Fair Value Measurement of Financial Instruments

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Fair Value Measurement of Financial Instruments

Piedmont considers its cash and cash equivalents, tenant receivables, restricted cash and escrows, accounts payable and accrued expenses, interest rate swap agreements, and debt to meet the definition of financial instruments. The following table sets forth the carrying and estimated fair value for each of Piedmont’s financial instruments, as well as its level within the GAAP fair value hierarchy, as of September 30, 2017 and December 31, 2016, respectively (in thousands):



	September 30, 2017					December 31, 2016
Financial Instrument	Carrying Value		Estimated Fair Value		Level Within Fair Value Hierarchy	Carrying Value		Estimated Fair Value		Level Within Fair Value Hierarchy
Assets:
Cash and cash equivalents⁽¹⁾	$	36,108	$	36,108	Level 1	$	6,992	$	6,992	Level 1
Tenant receivables, net⁽¹⁾	$	12,802	$	12,802	Level 1	$	26,494	$	26,494	Level 1
Restricted cash and escrows⁽¹⁾	$	1,260	$	1,260	Level 1	$	1,212	$	1,212	Level 1
Interest rate swaps	$	34	$	34	Level 2	$	—	$	—	Level 2
Liabilities:
Accounts payable and accrued expenses⁽¹⁾	$	13,465	$	13,465	Level 1	$	44,733	$	44,733	Level 1
Interest rate swaps	$	3,915	$	3,915	Level 2	$	8,169	$	8,169	Level 2
Debt, net	$	1,703,586	$	1,731,584	Level 2	$	2,020,475	$	2,027,436	Level 2


⁽¹⁾	For the periods presented, the carrying value of these financial instruments approximates estimated fair value due to their short-term maturity.

Piedmont's debt was carried at book value as of September 30, 2017 and December 31, 2016; however, Piedmont's estimate of its estimated fair value is disclosed in the table above. Piedmont uses widely accepted valuation techniques including discounted cash flow analysis based on the contractual terms of the debt facilities, including the period to maturity of each instrument, and uses observable market-based inputs for similar debt facilities which have transacted recently in the market. Therefore, the estimated fair values determined are considered to be based on significant other observable inputs (Level 2). Scaling adjustments are made to these inputs to make them applicable to the remaining life of Piedmont's outstanding debt. Piedmont has not changed its valuation technique for estimating the fair value of its debt.

Piedmont’s interest rate swap and forward starting interest rate swap agreements presented above, and further discussed in Note 5, are classified as “Interest rate swap” assets and liabilities in the accompanying consolidated balance sheets and were carried at estimated fair value as of September 30, 2017 and December 31, 2016. The valuation of these derivative instruments was determined using widely accepted valuation techniques including discounted cash flow analysis based on the contractual terms of the derivatives, including the period to maturity of each instrument, and uses observable market-based inputs, including interest rate curves and implied volatilities. Therefore, the estimated fair values determined are considered to be based on significant other observable inputs (Level 2). In addition, Piedmont considered both its own and the respective counterparties’ risk of nonperformance in determining the estimated fair value of its derivative financial instruments by estimating the current and potential future exposure under the derivative financial instruments that both Piedmont and the counterparties were at risk for as of the valuation date. The credit risk of Piedmont and its counterparties were factored into the calculation of the estimated fair value of the interest rate swaps; however, as of September 30, 2017 and December 31, 2016, this credit valuation adjustment did not comprise a material portion of the estimated fair value. Therefore, Piedmont believes that any unobservable inputs used to determine the estimated fair values of its derivative financial instruments are not significant to the fair value measurements in their entirety, and does not consider any of its derivative financial instruments to be Level 3 assets or liabilities.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Impairment Loss on Real Estate Assets

9 Months Ended

Sep. 30, 2017

Real Estate [Abstract]

Impairment Loss on Real Estate Assets

Piedmont recorded impairment loss on real estate assets for the three and nine months ended September 30, 2017 and 2016, respectively, as follows (in thousands):



	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
150 West Jefferson⁽¹⁾	$	—	$	—	$	—	$	8,258
9221 Corporate Boulevard ⁽²⁾	—		—		—		2,692
9200 and 9211 Corporate Boulevard⁽³⁾	—		22,951		—		22,951
Total impairment loss on real estate assets⁽⁴⁾	$	—	$	22,951	$	—	$	33,901


⁽¹⁾	Piedmont recognized an impairment loss on real estate assets based upon the difference between the carrying value of the asset and the anticipated contract sales price, less estimated selling costs.

⁽²⁾

Piedmont, using a probability-weighted model heavily weighted towards the short-term sale of the 9221 Corporate Boulevard building in Rockville, Maryland, determined that the carrying value would not be recovered from the undiscounted future operating cash flows expected from the use of the asset and its eventual disposition. As a result, Piedmont recognized a loss on impairment of approximately $2.7 million during the nine months ended September 30, 2016 calculated as the difference between the carrying value of the asset and the anticipated contract sales price, less estimated selling costs.

⁽³⁾

Piedmont elected to sell its remaining two assets and exit the Rockville, Maryland sub-market of Washington, D.C, after selling the 9221 Corporate Boulevard building in July 2016 (mentioned above). Upon management's change in its hold period assumption for the assets from a long-term hold to a near-term sale, Piedmont recognized an impairment loss of approximately $23.0 million. The impairment loss was calculated as the difference between the carrying value of the asset and the anticipated contracted sales price, less estimated selling costs. Piedmont reclassified the properties as held for sale, recognized an impairment loss, entered into a binding contract, and subsequently sold the 9200 and 9211 Corporate Boulevard buildings during the three months ended September 30, 2016.


⁽⁴⁾	The fair value measurements used in the evaluation of the non-financial assets above are considered to be Level 1 valuations within the fair value hierarchy as defined by GAAP, as there are direct observations and transactions involving the assets by unrelated, third-party purchasers.

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments Under Existing Lease Agreements Under its existing lease agreements, Piedmont may be required to fund significant tenant improvements, leasing commissions, and building improvements. In addition, certain agreements contain provisions that require Piedmont to issue corporate or property guarantees to provide funding for capital improvements or other financial obligations. Piedmont classifies its capital improvements into two categories: (i) improvements which maintain the building's existing asset value and its revenue generating capacity (“non-incremental capital expenditures”) and (ii) improvements which incrementally enhance the building's asset value by expanding its revenue generating capacity (“incremental capital expenditures”). As of September 30, 2017, commitments to fund potential non-incremental capital expenditures over the next five years for tenant improvements totaled approximately $32.1 million related to Piedmont's existing lease portfolio over the respective lease terms, the majority of which Piedmont estimates may be required to be funded over the next three years based on when the underlying leases commence. For most of Piedmont’s leases, the timing of the actual funding of these tenant improvements is largely dependent upon tenant requests for reimbursement. In some cases, these obligations may expire with the leases without further recourse to Piedmont. As of September 30, 2017, commitments for incremental capital expenditures for tenant improvements associated with executed leases totaled approximately $15.2 million. Contingencies Related to Tenant Audits/Disputes Certain lease agreements include provisions that grant tenants the right to engage independent auditors to audit their annual operating expense reconciliations. Such audits may result in the re-interpretation of language in the lease agreements which could result in the refund of previously recognized tenant reimbursement revenues, resulting in financial loss to Piedmont. Piedmont recorded no such reductions in reimbursement revenues related to such tenant audits/disputes during the three months ended September 30, 2017 and 2016, respectively, and $0.3 million and $0 of such reductions in reimbursement revenues related to such tenant audits/disputes during the nine months ended September 30, 2017 and 2016, respectively.

Property Dispositions and Assets Held for Sale

9 Months Ended

Sep. 30, 2017

Discontinued Operations and Disposal Groups [Abstract]

Property Dispositions and Assets Held for Sale

Properties sold during the nine months ended September 30, 2017 and 2016 did not meet the criteria to be reported as discontinued operations. The operational results for these properties prior to their sale dates are presented as continuing operations in the accompanying consolidated statements of income, and the gain/(loss) on sale is presented separately on the face of the income statement. Details of such properties sold are presented below (in thousands):



Buildings Sold	Location	Date of Sale	Gain/(Loss) on Sale			Net Sales Proceeds
1055 East Colorado Boulevard	Pasadena, California	April 21, 2016	$	29,461		$	60,076
Fairway Center II	Brea, California	April 28, 2016	$	14,405		$	33,062
1901 Main Street	Irvine, California	May 2, 2016	$	29,964		$	63,149
9221 Corporate Boulevard	Rockville, Maryland	July 27, 2016	$	(192	)	$	12,035
150 West Jefferson	Detroit, Michigan	July 29, 2016	$	(680	)	$	77,827
9200 and 9211 Corporate Boulevard	Rockville, Maryland	September 28, 2016	$	(41	)	$	12,518
Sarasota Commerce Center II	Sarasota, Florida	June 16, 2017	$	6,493		$	23,090
Two Independence Square	Washington, D.C.	July 5, 2017	$	109,516		$	352,180

Sale of the 8560 Upland Drive building

During the three months ended September 30, 2017, Piedmont sold its 72% interest in the 8560 Upland Drive building in Denver, Colorado for approximately $12.7 million which resulted in net sales proceeds of $12.3 million and a gain on sale of approximately $3.7 million, which is included in income from unconsolidated joint ventures in the accompanying consolidated statements of income.

Assets Held for Sale

In February 2017, Piedmont reclassified the Two Independence Square building from real estate assets held for use to real estate assets held for sale as a result of entering into a binding agreement to sell the property. The sale of the Two Independence Square building closed on July 5, 2017. Details of assets held for sale as of September 30, 2017 and December 31, 2016 are presented below (in thousands):



	September 30, 2017		December 31, 2016
Real estate assets held for sale, net:
Land	$	—	$	52,710
Building and improvements, less accumulated depreciation of $0 and $88,319 as of September 30, 2017 and December 31, 2016, respectively	—		173,218
Construction in progress	—		11
Total real estate assets held for sale, net	$	—	$	225,939

Other assets held for sale, net:
Straight-line rent receivables	$	—	$	2,059
Prepaid expenses and other assets	—		454
Deferred lease costs, less accumulated amortization of $0 and $2,825 as of September 30, 2017 and December 31, 2016, respectively	—		7,302
Total other assets held for sale, net	$	—	$	9,815

- Definition

The entire disclosure related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

+ References

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-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721659-107760

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721671-107760

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5D
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721677-107760

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1474-107760

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721683-107760

+ Details

Stock Based Compensation

9 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock Based Compensation

The Compensation Committee of Piedmont's Board of Directors has periodically granted deferred stock awards to all of Piedmont's employees and independent directors. Employee awards typically vest ratably over a multi-year period and independent director awards vest over one year. Certain employees' long-term equity incentive program is split equally between the time-vested awards described above and a multi-year performance share program whereby awards may be earned based upon Piedmont's total stockholder return ("TSR") relative to a peer group's TSR. The peer group is predetermined by the Board of Directors. Any shares earned are awarded at the end of the multi-year performance period and vest upon award.

A rollforward of Piedmont's equity based award activity for the nine months ended September 30, 2017 is as follows:



	Shares		Weighted-Average Grant Date Fair Value
Unvested Stock Awards as of December 31, 2016	944,223		$	19.44
Deferred Stock Awards Granted	299,251		$	21.38
Change in Estimated Potential Future Performance Share Awards, net of forfeitures	(7,828	)	$	23.65
Performance Stock Awards Vested	(118,446	)	$	22.00
Deferred Stock Awards Vested	(302,474	)	$	19.35
Deferred Stock Awards Forfeited	(7,200	)	$	19.79
Unvested Stock Awards as of September 30, 2017	807,526		$	21.39

The following table provides additional information regarding stock award activity during the three and nine months ended September 30, 2017 and 2016, respectively (in thousands, except per share amounts):



	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Weighted-Average Grant Date Fair Value of Deferred Stock Granted During the Period	$	—	$	—	$	21.38	$	19.96
Total Grant Date Fair Value of Deferred Stock Vested During the Period	$	11	$	108	$	5,852	$	4,766
Share-based Liability Awards Paid During the Period⁽¹⁾	$	—	$	—	$	2,877	$	1,127


⁽¹⁾	Amounts reflect the issuance of performance share awards related to the 2014-16 and 2013-15 Performance Share Plans during the nine months ended September 30, 2017 and 2016, respectively.

A detail of Piedmont’s outstanding stock awards as of September 30, 2017 is as follows:



Date of grant	Type of Award	Net Shares Granted ⁽¹⁾	Grant Date Fair Value		Vesting Schedule	Unvested Shares as of September 30, 2017
January 3, 2014	Deferred Stock Award	86,769	$	16.56	Of the shares granted, 20% vested or will vest on January 3, 2015, 2016, 2017, 2018, and 2019, respectively.	35,094
May 1, 2015	Deferred Stock Award	216,837	$	17.59	Of the shares granted, 25% vested on the date of grant, and 25% vested or will vest on May 1, 2016, 2017, and 2018, respectively.	67,114
May 1, 2015	Fiscal Year 2015-2017 Performance Share Program	—	$	18.42	Shares awarded, if any, will vest immediately upon determination of award in 2018.	143,846	⁽²⁾
May 24, 2016	Deferred Stock Award	233,011	$	19.91	Of the shares granted, 25% vested on the date of grant, and 25% vested or will vest on May 24, 2017, 2018, and 2019, respectively.	133,092
May 24, 2016	Fiscal Year 2016-2018 Performance Share Program	—	$	23.02	Shares awarded, if any, will vest immediately upon determination of award in 2019.	103,790	⁽²⁾
May 18, 2017	Deferred Stock Award-Board of Directors	26,187	$	21.38	Of the shares granted, 100% will vest by May 18, 2018.	26,187
May 18, 2017	Deferred Stock Award	246,740	$	21.38	Of the shares granted, 25% vested on the date of grant, and 25% vested or will vest on May 18, 2018, 2019, and 2020, respectively.	200,899
May 18, 2017	Fiscal Year 2017-2019 Performance Share Program	—	$	30.45	Shares awarded, if any, will vest immediately upon determination of award in 2020.	97,504	⁽²⁾
Total						807,526


⁽¹⁾	Amounts reflect the total grant to employees and independent directors, net of shares surrendered upon vesting to satisfy required minimum tax withholding obligations through September 30, 2017.


⁽²⁾	Estimated based on Piedmont's cumulative TSR for the respective performance period through September 30, 2017. Share estimates are subject to change in future periods based upon Piedmont's relative performance compared to its peers' total stockholder return.

During the three months ended September 30, 2017 and 2016, Piedmont recognized approximately $1.3 million and $2.0 million of compensation expense related to stock awards, all of which is related to the amortization of unvested shares. During the nine months ended September 30, 2017 and 2016, Piedmont recognized approximately $7.0 million and $7.7 million of compensation expense related to stock awards, of which $5.2 million and $6.2 million related to the amortization of unvested shares, respectively. During the nine months ended September 30, 2017, a net total of 254,873 shares were issued to employees and independent directors. As of September 30, 2017, approximately $5.1 million of unrecognized compensation cost related to unvested deferred stock awards remained, which Piedmont will record in its consolidated statements of income over a weighted-average vesting period of approximately one year.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References + Details

Earnings Per Share

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Earnings Per Share

There are no adjustments to “Net income applicable to Piedmont” for the diluted earnings per share computations. Adjustments to the carrying amount of non-controlling interest as a result of the measurement of a redeemable equity participation do not impact net income or comprehensive income; rather such adjustments are treated as the repurchase of a non-controlling interest.

Net income per share-basic is calculated as net income available to common stockholders divided by the weighted average number of common shares outstanding during the period. Net income per share-diluted is calculated as net income available to common stockholders divided by the diluted weighted average number of common shares outstanding during the period, including unvested deferred stock awards. Diluted weighted average number of common shares reflects the potential dilution under the treasury stock method that would occur if the remaining unvested deferred stock awards vested and resulted in additional common shares outstanding. Unvested deferred stock awards which are determined to be anti-dilutive are not included in the calculation of diluted weighted average common shares.

The following table reconciles the denominator for the basic and diluted earnings per share computations shown on the consolidated statements of income for the three and nine months ended September 30, 2017 and 2016, respectively (in thousands):



	Three Months Ended		Nine Months Ended
	September 30, 2017	September 30, 2016	September 30, 2017	September 30, 2016
Weighted-average common shares – basic	145,416	145,231	145,372	145,229
Plus: Incremental weighted-average shares from time-vested deferred and performance stock awards	303	438	308	372
Weighted-average common shares – diluted	145,719	145,669	145,680	145,601

Common stock issued and outstanding as of period end			145,295	145,234

Guarantor and Non-Guarantor Financial Information

9 Months Ended

Sep. 30, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Guarantor and Non-Guarantor Financial Information

The following condensed consolidating financial information for Piedmont Operating Partnership, L.P. (the "Issuer"), Piedmont Office Realty Trust, Inc. (the "Guarantor"), and the other directly and indirectly owned subsidiaries of the Guarantor (the "Non-Guarantor Subsidiaries") is provided pursuant to the requirements of Rule 3-10 of Regulation S-X regarding financial statements of guarantors and issuers of guaranteed registered securities. The Issuer is a wholly-owned subsidiary of the Guarantor, and all guarantees by the Guarantor of securities issued by the Issuer are full and unconditional. The principal elimination entries relate to investments in subsidiaries and intercompany balances and transactions, including transactions with the Non-Guarantor Subsidiaries.



Condensed Consolidated Balance Sheets
As of September 30, 2017
(in thousands)	Issuer		Guarantor			Non-Guarantor Subsidiaries		Eliminations			Consolidated
Assets:
Real estate assets, at cost:
Land	$	43,929	$	—		$	571,005	$	—		$	614,934
Buildings and improvements, less accumulated depreciation	206,700		—			2,516,763		(300		)	2,723,163
Intangible lease assets, less accumulated amortization	317		—			78,383		—			78,700
Construction in progress	797		—			8,160		—			8,957
Total real estate assets	251,743		—			3,174,311		(300		)	3,425,754
Investments in and amounts due from unconsolidated joint ventures	49		—			—		—			49
Cash and cash equivalents	25,884		150			10,074		—			36,108
Tenant and straight-line rent receivables, net	17,556		—			177,855		—			195,411
Advances to affiliates	6,257,405		1,576,739			—		(7,834,144		)	—
Investment in subsidiary	—		3,538,945			177		(3,539,122		)	—
Notes receivable	88,910		—			144,500		(233,410		)	—
Prepaid expenses, restricted cash, escrows, and other assets	4,905		38			25,358		(809		)	29,492
Goodwill	98,918		—			—		—			98,918
Interest rate swaps	34		—			—		—			34
Deferred lease costs, net	13,927		—			260,957		—			274,884
Total assets	$	6,759,331	$	5,115,872		$	3,793,232	$	(11,607,785	)	$	4,060,650
Liabilities:
Debt, net	$	1,511,587	$	—		$	425,409	$	(233,410	)	$	1,703,586
Accounts payable, accrued expenses, and accrued capital expenditures	16,546		652			91,731		(809		)	108,120
Advances from affiliates	790,748		5,226,546			1,915,105		(7,932,399		)	—
Deferred income	3,728		—			26,242		—			29,970
Intangible lease liabilities, net	—		—			41,064		—			41,064
Interest rate swaps	3,915		—			—		—			3,915
Total liabilities	2,326,524		5,227,198			2,499,551		(8,166,618		)	1,886,655
Stockholders’ Equity:
Common stock	—		1,453			—		—			1,453
Additional paid-in capital	3,534,946		3,679,578			1,304		(3,539,122		)	3,676,706
Retained/(cumulative distributions in excess of) earnings	892,461		(3,792,357		)	1,290,513		97,955			(1,511,428		)
Other comprehensive loss	5,400		—			—		—			5,400
Piedmont stockholders’ equity	4,432,807		(111,326		)	1,291,817		(3,441,167		)	2,172,131
Noncontrolling interest	—		—			1,864		—			1,864
Total stockholders’ equity	4,432,807		(111,326		)	1,293,681		(3,441,167		)	2,173,995
Total liabilities and stockholders’ equity	$	6,759,331	$	5,115,872		$	3,793,232	$	(11,607,785	)	$	4,060,650



Condensed Consolidated Balance Sheets
As of December 31, 2016
(in thousands)	Issuer		Guarantor			Non-Guarantor Subsidiaries		Eliminations			Consolidated
Assets:
Real estate assets, at cost:
Land	$	46,133	$	—		$	571,005	$	—		$	617,138
Buildings and improvements, less accumulated depreciation	228,194		—			2,526,212		(300		)	2,754,106
Intangible lease assets, less accumulated amortization	725		—			98,970		—			99,695
Construction in progress	145		—			34,669		—			34,814
Real estate assets held for sale, net	—		—			225,939		—			225,939
Total real estate assets	275,197		—			3,456,795		(300		)	3,731,692
Investments in and amounts due from unconsolidated joint ventures	7,360		—			—		—			7,360
Cash and cash equivalents	3,674		150			3,168		—			6,992
Tenant and straight-line rent receivables, net	20,159		—			170,124		—			190,283
Advances to affiliates	6,464,135		1,315,616			—		(7,779,751		)	—
Investment in subsidiary	—		3,630,564			181		(3,630,745		)	—
Notes receivable	88,910		—			95,790		(184,700		)	—
Prepaid expenses, restricted cash, escrows, and other assets	6,189		—			20,121		(1,897		)	24,413
Goodwill	98,918		—			—		—			98,918
Deferred lease costs, net	16,550		—			282,145		—			298,695
Other assets held for sale, net	—		—			9,815		—			9,815
Total assets	$	6,981,092	$	4,946,330		$	4,038,139	$	(11,597,393	)	$	4,368,168
Liabilities:
Debt, net	$	1,701,933	$	—		$	503,242	$	(184,700	)	$	2,020,475
Accounts payable, accrued expenses, and accrued capital expenditures	17,365		31,230			118,712		(1,897		)	165,410
Advances from affiliates	708,340		5,071,521			2,098,146		(7,878,007		)	—
Deferred income	5,206		—			23,200		—			28,406
Intangible lease liabilities, net	—		—			48,005		—			48,005
Interest rate swaps	8,169		—			—		—			8,169
Total liabilities	2,441,013		5,102,751			2,791,305		(8,064,604		)	2,270,465
Stockholders’ Equity:
Common stock	—		1,452			—		—			1,452
Additional paid-in capital	3,626,564		3,676,000			1,309		(3,630,745		)	3,673,128
Retained/(cumulative distributions in excess of) earnings	911,411		(3,833,873		)	1,243,643		97,956			(1,580,863		)
Other comprehensive income	2,104		—			—		—			2,104
Piedmont stockholders’ equity	4,540,079		(156,421		)	1,244,952		(3,532,789		)	2,095,821
Noncontrolling interest	—		—			1,882		—			1,882
Total stockholders’ equity	4,540,079		(156,421		)	1,246,834		(3,532,789		)	2,097,703
Total liabilities and stockholders’ equity	$	6,981,092	$	4,946,330		$	4,038,139	$	(11,597,393	)	$	4,368,168



Condensed Consolidated Statements of Income
For the three months ended September 30, 2017
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	10,232		$	—		$	103,544		$	(426	)	$	113,350
Tenant reimbursements	2,376			—			21,562			(142		)	23,796
Property management fee revenue	—			—			4,553			(4,112		)	441
	12,608			—			129,659			(4,680		)	137,587
Expenses:
Property operating costs	5,372			—			53,398			(4,680		)	54,090
Depreciation	3,199			—			26,801			—			30,000
Amortization	740			—			17,383			—			18,123
General and administrative	1,539			77			5,002			—			6,618
	10,850			77			102,584			(4,680		)	108,831
Real estate operating income/(loss)	1,758			(77		)	27,075			—			28,756
Other income (expense):
Interest expense	(13,795		)	—			(6,354		)	3,966			(16,183		)
Other income/(expense)	2,404			—			1,852			(3,966		)	290
Equity in income of unconsolidated joint ventures	3,754			—			—			—			3,754
	(7,637		)	—			(4,502		)	—			(12,139		)
Income/(loss) from continuing operations	(5,879		)	(77		)	22,573			—			16,617
Discontinued operations:
Operating income	—			—			—			—			—
Income from discontinued operations	—			—			—			—			—
Gain/(loss) on sale of real estate assets, net	(4		)	—			109,516			—			109,512
Net income/(loss)	(5,883		)	(77		)	132,089			—			126,129
Plus: Net income applicable to noncontrolling interest	—			—			4			—			4
Net income/(loss) applicable to Piedmont	$	(5,883	)	$	(77	)	$	132,093		$	—		$	126,133



Condensed Consolidated Statements of Income
For the three months ended September 30, 2016
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	12,862		$	—		$	101,423		$	(464	)	$	113,821
Tenant reimbursements	3,430			—			20,970			(237		)	24,163
Property management fee revenue	—			—			3,985			(3,484		)	501
	16,292			—			126,378			(4,185		)	138,485
Expenses:
Property operating costs	7,820			—			51,287			(4,240		)	54,867
Depreciation	3,617			—			27,993			—			31,610
Amortization	863			—			17,777			—			18,640
Impairment loss on real estate assets	—			—			22,951			—			22,951
General and administrative	7,187			83			9,016			(8,857		)	7,429
	19,487			83			129,024			(13,097		)	135,497
Real estate operating income/(loss)	(3,195		)	(83		)	(2,646		)	8,912			2,988
Other income (expense):
Interest expense	(11,799		)	—			(6,949		)	3,252			(15,496		)
Other income/(expense)	2,608			—			(76		)	(3,252		)	(720		)
Net recoveries from casualty events	—			—			34			—			34
Equity in income of unconsolidated joint ventures	129			—			—			—			129
	(9,062		)	—			(6,991		)	—			(16,053		)
Income/(loss) from continuing operations	(12,257		)	(83		)	(9,637		)	8,912			(13,065		)
Discontinued operations:
Operating income	—			—			1			—			1
Income from discontinued operations	—			—			1			—			1
Gain/(loss) on sale of real estate assets, net	134			—			(191		)	—			(57		)
Net income/(loss)	(12,123		)	(83		)	(9,827		)	8,912			(13,121		)
Plus: Net income applicable to noncontrolling interest	—			—			14			—			14
Net income/(loss) applicable to Piedmont	$	(12,123	)	$	(83	)	$	(9,813	)	$	8,912		$	(13,107	)



Condensed Consolidated Statements of Income
For the nine months ended September 30, 2017
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	32,749		$	—		$	329,669		$	(1,370	)	$	361,048
Tenant reimbursements	8,341			—			64,372			(373		)	72,340
Property management fee revenue	—			—			13,753			(12,412		)	1,341
	41,090			—			407,794			(14,155		)	434,729
Expenses:
Property operating costs	17,027			—			162,381			(14,155		)	165,253
Depreciation	9,943			—			80,884			—			90,827
Amortization	2,399			—			55,453			—			57,852
General and administrative	4,798			261			18,191			—			23,250
	34,167			261			316,909			(14,155		)	337,182
Real estate operating income/(loss)	6,923			(261		)	90,885			—			97,547
Other income (expense):
Interest expense	(43,049		)	—			(20,868		)	11,256			(52,661		)
Other income/(expense)	6,873			—			4,611			(11,256		)	228
Equity in income of unconsolidated joint ventures	3,872			—			—			—			3,872
	(32,304		)	—			(16,257		)	—			(48,561		)
Income/(loss) from continuing operations	(25,381		)	(261		)	74,628			—			48,986
Discontinued operations:
Operating income	—			—			—			—			—
Income from discontinued operations	—			—			—			—			—
Gain on sale of real estate assets, net	6,430			—			109,521			—			115,951
Net income/(loss)	(18,951		)	(261		)	184,149			—			164,937
Plus: Net income applicable to noncontrolling interest	—			—			10			—			10
Net income/(loss) applicable to Piedmont	$	(18,951	)	$	(261	)	$	184,159		$	—		$	164,947



Condensed Consolidated Statements of Income
For the nine months ended September 30, 2016
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	42,990		$	—		$	299,319		$	(1,983	)	$	340,326
Tenant reimbursements	10,455			—			59,950			(405		)	70,000
Property management fee revenue	—			—			12,480			(11,002		)	1,478
	53,445			—			371,749			(13,390		)	411,804
Expenses:
Property operating costs	24,583			—			150,369			(13,514		)	161,438
Depreciation	12,993			—			81,955			—			94,948
Amortization	2,854			—			50,994			—			53,848
Impairment loss of real estate assets	8,259			—			25,642			—			33,901
General and administrative	22,802			251			28,881			(28,416		)	23,518
	71,491			251			337,841			(41,930		)	367,653
Real estate operating income/(loss)	(18,046		)	(251		)	33,908			28,540			44,151
Other income (expense):
Interest expense	(36,159		)	—			(20,354		)	8,219			(48,294		)
Other income/(expense)	7,008			282			462			(8,219		)	(467		)
Net recoveries from casualty events	—			—			34			—			34
Equity in income of unconsolidated joint ventures	354			—			—			—			354
	(28,797		)	282			(19,858		)	—			(48,373		)
Net income/(loss)	(46,843		)	31			14,050			28,540			(4,222		)
Discontinued operations:
Operating income	—			—			—			—			—
Income from discontinued operations	—			—			—			—			—
Gain on sale of real estate assets, net	30,096			—			43,662			—			73,758
Net income/(loss)	(16,747		)	31			57,712			28,540			69,536
Plus: Net income applicable to noncontrolling interest	—			—			7			—			7
Net income/(loss) applicable to Piedmont	$	(16,747	)	$	31		$	57,719		$	28,540		$	69,543



Condensed Consolidated Statements of Cash Flows
For the nine months ended September 30, 2017
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Net Cash Provided by/(Used in) Operating Activities	$	(15,467	)	$	4,335		$	187,464		$	—		$	176,332

Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	(793		)	—			(64,614		)	—			(65,407		)
Intercompany note receivable	—			—			(48,710		)	48,710			—
Net sales proceeds from wholly-owned properties	23,028			—			352,171			—			375,199
Net sales proceeds received from unconsolidated joint ventures	12,334			—			—			—			12,334
Investments in unconsolidated joint ventures	(1,162		)	—			—			—			(1,162		)
Deferred lease costs paid	(858		)	—			(18,561		)	—			(19,419		)
Net cash provided by investing activities	32,549			—			220,286			48,710			301,545
Cash Flows from Financing Activities:
Debt issuance costs paid	(102		)	—			1			—			(101		)
Proceeds from debt	147,000			—			—			—			147,000
Repayments of debt	(325,000		)	—			(141,046		)	—			(466,046		)
Intercompany note payable	(14,289		)	—			62,999			(48,710		)	—
Costs of issuance of common stock	—			(97		)	—			—			(97		)
Value of shares withheld to pay tax obligations related to employee stock compensation	—			(3,385		)	—			—			(3,385		)
Repurchases of common stock as part of announced plan	—			(3,895		)	—			—			(3,895		)
(Distributions to)/repayments from affiliates	197,519			125,271			(322,790		)	—			—
Dividends paid and discount on dividend reinvestments	—			(122,229		)	(8		)	—			(122,237		)
Net cash used in financing activities	5,128			(4,335		)	(400,844		)	(48,710		)	(448,761		)
Net increase in cash and cash equivalents	22,210			—			6,906			—			29,116
Cash and cash equivalents, beginning of period	3,674			150			3,168			—			6,992
Cash and cash equivalents, end of period	$	25,884		$	150		$	10,074		$	—		$	36,108



Condensed Consolidated Statements of Cash Flows
For the nine months ended September 30, 2016
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Net Cash Provided by/(Used in) Operating Activities	$	(18,977	)	$	4,121		$	158,352		$	28,540		$	172,036

Cash Flows from Investing Activities:
Investment in real estate assets, consolidated joint venture, and real estate related intangibles, net of accruals	(24,255		)	—			(296,884		)	—			(321,139		)
Intercompany note receivable	440			—			(71,900		)	71,460			—
Net sales proceeds from wholly-owned properties	187,192			—			117,710			—			304,902
Deferred lease costs paid	(2,021		)	—			(13,324		)	—			(15,345		)
Net cash provided by/(used in) investing activities	161,356			—			(264,398		)	71,460			(31,582		)
Cash Flows from Financing Activities:
Debt issuance costs paid	(212		)	—			—			—			(212		)
Proceeds from debt	552,000			—			—			—			552,000
Repayments of debt	(421,000		)	—			(168,532		)	—			(589,532		)
Intercompany note payable	(9,600		)	—			81,060			(71,460		)	—
Costs of issuance of common stock	—			(239		)	—			—			(239		)
Value of shares withheld to pay tax obligations related to employee stock compensation	—			(2,328		)	—			—			(2,328		)
Repurchases of common stock as part of announced plan	—			(7,943		)	—			—			(7,943		)
(Distributions to)/repayments from affiliates	(262,150		)	97,990			192,700			(28,540		)	—
Dividends paid and discount on dividend reinvestments	—			(91,601		)	(8		)	—			(91,609		)
Net cash provided by/(used in) financing activities	(140,962		)	(4,121		)	105,220			(100,000		)	(139,863		)
Net increase/(decrease) in cash and cash equivalents	1,417			—			(826		)	—			591
Cash and cash equivalents, beginning of period	2,174			150			3,117			—			5,441
Cash and cash equivalents, end of period	$	3,591		$	150		$	2,291		$	—		$	6,032

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Fourth Quarter Dividend Declaration On October 31, 2017, the Board of Directors of Piedmont declared dividends for the fourth quarter 2017 in the amount of $0.21 per common share outstanding to stockholders of record as of the close of business on November 24, 2017. Such dividends are to be paid on January 4, 2018.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	The consolidated financial statements of Piedmont have been prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”), including the instructions to Form 10-Q and Article 10 of Regulation S-X, and do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the statements for the unaudited interim periods presented include all adjustments, which are of a normal and recurring nature, necessary for a fair presentation of the results for such periods. Results for these interim periods are not necessarily indicative of a full year’s results.
Principles of Consolidation	Piedmont’s consolidated financial statements include the accounts of Piedmont, Piedmont’s wholly-owned subsidiaries, any variable interest entity ("VIE") for which Piedmont or any of its wholly-owned subsidiaries is considered to have the power to direct the activities of the entity and the obligation to absorb losses/right to receive benefits, or any entity in which Piedmont or any of its wholly-owned subsidiaries owns a controlling interest. In determining whether Piedmont or Piedmont OP has a controlling interest, the following factors, among others, are considered: equity ownership, voting rights, protective rights of investors, and participatory rights of investors. For further information, refer to the financial statements and footnotes included in Piedmont’s Amended Annual Report on Form 10-K/A for the year ended December 31, 2016. All intercompany balances and transactions have been eliminated upon consolidation. Further, Piedmont has formed special purpose entities to acquire and hold real estate. Each special purpose entity is a separate legal entity. Consequently, the assets of these special purpose entities are not available to all creditors of Piedmont. The assets owned by these special purpose entities are being reported on a consolidated basis with Piedmont’s assets for financial reporting purposes only.
Use of Estimates	Use of Estimates The preparation of the accompanying consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the accompanying consolidated financial statements and notes. Actual results could differ from those estimates.
Income Taxes	Income Taxes Piedmont has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended, and has operated as such, beginning with its taxable year ended December 31, 1998. To qualify as a REIT, Piedmont must meet certain organizational and operational requirements, including a requirement to distribute at least 90% of its annual REIT taxable income. As a REIT, Piedmont is generally not subject to federal income taxes, subject to fulfilling, among other things, this distribution requirement. Piedmont is subject to certain taxes related to the operations of properties in certain locations, as well as operations conducted by its taxable REIT subsidiary, POH, which have been provided for in the financial statements.
Reclassifications	Reclassifications Certain prior period amounts presented in Piedmont's Amended Annual Report on Form 10-K/A for the year ended December 31, 2016 have been reclassified to conform to the current period financial statement presentation. The reclassifications relate to the Two Independence Square building, located in Washington, D.C., which was first classified as held for sale as of March 31, 2017, and was sold on July 5, 2017. Applicable balances related to the same asset remain classified as held for sale as of December 31, 2016.
Recent Accounting Pronouncements	Recent Accounting Pronouncements The Financial Accounting Standards Board (the "FASB") has issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09") and Accounting Standards Update No. 2016-08, Revenue from Contracts with Customers (Topic 606) Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08"). The amendments in ASU 2014-09, which are further clarified in ASU 2016-08, as well as Accounting Standards Update 2016-10, Accounting Standards Update 2016-12, and Accounting Standards Update 2016-20 (collectively the "Revenue Recognition Amendments"), change the criteria for the recognition of certain revenue streams to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services using a five-step determination process. Steps 1 through 5 involve (i) identifying contracts with a customer, (ii) identifying the performance obligations in the contract, (iii) determining the transaction price, (iv) allocating the transaction price to the performance obligations, and (v) recognizing revenue as an entity satisfies a performance obligation. The revenues impacted by the Revenue Recognition Amendments include a portion of Piedmont's tenant reimbursement revenues and property management fee revenues. Lease contracts and reimbursement revenues associated with property taxes and insurance are specifically excluded from the Revenue Recognition Amendments. The Revenue Recognition Amendments are effective in the first quarter of 2018 for Piedmont. Management has substantially completed its initial assessment of the impact of adoption of the Revenue Recognition Amendments. Approximately 90% of Piedmont's total revenues are derived from either long-term leases with its tenants or reimbursement of property tax and insurance expenses, which are excluded from the scope of the Revenue Recognition Amendments. In addition, based on management's assessment to date, Piedmont does not expect the timing of the recognition of reimbursement revenue and revenue from management agreements to change as a result of the new guidance, though certain classifications will change between rental revenue and tenant reimbursements. Finally, management has determined, and the FASB has confirmed, that the evaluation of non-lease components under the new Revenue Recognition Amendments will not be effective until Accounting Standards Update No. 2016-02, Leases (Topic 842), ("ASU 2016-02") becomes effective (see further discussion below), which will be first quarter of 2019 for Piedmont. Although management continues to evaluate the guidance and disclosures required by the Revenue Recognition Amendments, Piedmont does not anticipate any material impact to its consolidated financial statements as a result of adoption. The FASB has issued Accounting Standards Update No. 2017-05, Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets ("ASU 2017-05"). The provisions of ASU 2017-05 define the term "in substance nonfinancial asset" as a financial asset promised to a counterparty in a contract if substantially all of the fair value of the assets (recognized and unrecognized) is concentrated in nonfinancial assets. Further, it states that nonfinancial assets should be derecognized once the counterparty obtains control. Finally, the amendments provide clarification for partial sales of nonfinancial assets. ASU 2017-05 is effective concurrent with the Revenue Recognition Amendments (detailed above), which will be the first quarter of 2018 for Piedmont. Although management continues to evaluate the guidance and disclosures required by ASU 2017-05, Piedmont does not anticipate a material change in how it recognizes, measures, and classifies the gain or loss on the disposition of real estate in its consolidated financial statements as a result of adoption. The FASB has issued Accounting Standards Update No. 2016-01, Financial Instruments - Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). The amendments in ASU 2016-01 require equity investments, except those accounted for under the equity method of accounting, to be measured at estimated fair value with changes in fair value recognized in net income. Additionally, ASU 2016-01 simplifies the impairment assessment of equity investments, and eliminates certain disclosure requirements. The amendments in ASU 2016-01 are effective in the first quarter of 2018, and Piedmont does not anticipate any material impact to its consolidated financial statements as a result of adoption. The FASB has issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash (a consensus of the FASB Emerging Issues Task Force) ("ASU 2016-18"). The provisions of ASU 2016-18 require entities to show changes in restricted cash and cash equivalents in addition to cash and cash equivalents in the statement of cash flows. As a result, entities will no longer present transfers between restricted and unrestricted cash in the statement of cash flows. Disclosures are required to reconcile the amount presented on the statement of cash flows to the balance sheet, as well as disclosing the nature of restriction on the restricted cash balances. ASU 2016-18 is effective for Piedmont in the first quarter of 2018, with early adoption permitted. Piedmont does not anticipate any material impact to its consolidated financial statements as a result of adoption. The FASB has issued ASU 2016-02, which fundamentally changes the definition of a lease, as well as the accounting for operating leases by requiring lessees to recognize assets and liabilities which arise from the lease, consisting of a liability to make lease payments (the lease liability) and a right-of-use asset, representing the right to use the leased asset over the term of the lease. Accounting for leases by lessors is substantially unchanged from prior practice as lessors will continue to recognize lease revenue on a straight-line basis; however, ASU 2016-02 defines certain tenant reimbursements as non-lease components which will be subject to the guidance under ASU 2014-09. The amendments in ASU 2016-02 are effective in the first quarter of 2019, and Piedmont is currently evaluating the potential impact of adoption. The FASB has issued Accounting Standards Update No. 2016-13, Financial Instruments—Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). The provisions of ASU 2016-13 replace the "incurred loss" approach with an "expected loss" model for impairing trade and other receivables, held-to-maturity debt securities, net investment in leases, and off-balance-sheet credit exposures, which will generally result in earlier recognition of allowances for credit losses. Additionally, the provisions change the classification of credit losses related to available-for-sale securities to an allowance, rather than a direct reduction of the amortized cost of the securities. ASU 2016-13 is effective in the first quarter of 2020, with early adoption permitted as of January 1, 2019. Piedmont is currently evaluating the potential impact of adoption. The FASB has issued Accounting Standards Update No. 2017-04, Intangibles—Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment ("ASU 2017-04"). The provisions of ASU 2017-04 simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test, which is generally performed annually unless events or circumstances arise which would necessitate evaluating the carrying value for impairment in the interim. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a entity’s goodwill with the carrying amount of that goodwill by determining the fair value of its assets and liabilities (including unrecognized assets and liabilities) following the procedures that would be required in a business combination. Under the provisions of ASU 2017-04, an entity would instead recognize an impairment charge for the amount by which the carrying amount exceeds the entity’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that entity. ASU 2017-04 is effective in the first quarter of 2020, with early adoption permitted as of the first interim or annual impairment test of goodwill after January 1, 2017. Piedmont is currently evaluating the potential impact of adoption.
Risk Management Objective of Using Derivatives	Risk Management Objective of Using Derivatives In addition to operational risks which arise in the normal course of business, Piedmont is exposed to economic risks such as interest rate, liquidity, and credit risk. In certain situations, Piedmont has entered into derivative financial instruments such as interest rate swap agreements and other similar agreements to manage interest rate risk exposure arising from current or future variable rate debt transactions. Interest rate swap agreements involve the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. Piedmont’s objective in using interest rate derivatives is to add stability to interest expense and to manage its exposure to interest rate movements.

- Definition

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

+ References + Details

Debt (Tables)

9 Months Ended

Sep. 30, 2017

Debt Disclosure [Abstract]

Schedule of Debt

The following table summarizes the terms of Piedmont’s indebtedness outstanding as of September 30, 2017 and December 31, 2016 (in thousands):



Facility ⁽¹⁾	Stated Rate		Effective Rate ⁽²⁾			Maturity		Amount Outstanding as of
Facility ⁽¹⁾	Stated Rate		Effective Rate ⁽²⁾			Maturity		September 30, 2017		December 31, 2016
Secured (Fixed)
$140 Million WDC Fixed-Rate Loans	5.76	%	5.76	%		11/1/2017		$	—	$	140,000
$35 Million Fixed-Rate Loan ⁽³⁾	5.55	%	3.75	%		9/1/2021		30,903		31,583
$160 Million Fixed-Rate Loan ⁽⁴⁾	3.48	%	3.58	%		7/5/2022		160,000		160,000
Net premium and unamortized debt issuance costs								1,020		1,161
Subtotal/Weighted Average ⁽⁵⁾	3.82	%						191,923		332,744
Unsecured (Variable and Fixed)
$170 Million Unsecured 2015 Term Loan ⁽⁶⁾	LIBOR + 1.125%		2.37	%		5/15/2018		170,000		170,000
$300 Million Unsecured 2013 Term Loan	LIBOR + 1.20%		2.78	%	⁽⁷⁾	1/31/2019		300,000		300,000
$500 Million Unsecured 2015 Line of Credit ⁽⁶⁾	LIBOR + 1.00%		—	%		6/18/2019	⁽⁸⁾	—		178,000
$300 Million Unsecured 2011 Term Loan	LIBOR + 1.15%		3.35	%	⁽⁷⁾	1/15/2020		300,000		300,000
$350 Million Senior Notes	3.40	%	3.43	%		6/01/2023		350,000		350,000
$400 Million Senior Notes	4.45	%	4.10	%		3/15/2024		400,000		400,000
Discounts and unamortized debt issuance costs								(8,337)		(10,269)
Subtotal/Weighted Average ⁽⁵⁾	3.43	%						1,511,663		1,687,731
Total/Weighted Average ⁽⁵⁾	3.47	%						$	1,703,586	$	2,020,475


⁽¹⁾	Other than the $35 Million Fixed-Rate Loan, all of Piedmont’s outstanding debt as of September 30, 2017 and December 31, 2016 is interest-only.


⁽²⁾	Effective rate after consideration of settled or in-place interest rate swap agreements, issuance premiums/discounts, and/or fair market value adjustments upon assumption of debt.


⁽³⁾	Collateralized by the 5 Wall Street building in Burlington, Massachusetts.


⁽⁴⁾	Collateralized by the 1901 Market Street building in Philadelphia, Pennsylvania.


⁽⁵⁾	Weighted average is based on contractual balance of outstanding debt and the stated or effectively fixed interest rates in the table as of September 30, 2017.


⁽⁶⁾	On a periodic basis, Piedmont may select from multiple interest rate options, including the prime rate and various-length LIBOR locks. All LIBOR selections are subject to an additional spread over the selected rate based on Piedmont’s current credit rating.


⁽⁷⁾	Facility has a stated variable rate; however, Piedmont has entered into interest rate swap agreements which effectively fix, exclusive of Piedmont's credit rating, the rate shown as the effective rate.


⁽⁸⁾	Piedmont may extend the term for up to one additional year (through two available six month extensions to a final extended maturity date of June 18, 2020) provided Piedmont is not then in default and upon payment of extension fees.

Variable Interest Entities (Tables)

9 Months Ended

Sep. 30, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Variable Interest Entities



Entity	Piedmont’s % Ownership of Entity		Related Building	Consolidated/ Unconsolidated	Net Carrying Amount as of September 30, 2017		Net Carrying Amount as of December 31, 2016			Primary Beneficiary Considerations
1201 Eye Street N.W. Associates, LLC	98.6%	⁽¹⁾	1201 Eye Street	Consolidated	$	82.1	$	(6.7	)	In accordance with the partnership’s governing documents, Piedmont currently receives 100% of the cash flow of the entity and has sole discretion in directing the management and leasing activities of the building.
1225 Eye Street N.W. Associates, LLC	98.1%	⁽¹⁾	1225 Eye Street	Consolidated	$	66.2	$	9.9		In accordance with the partnership’s governing documents, Piedmont currently receives 100% of the cash flow of the entity and has sole discretion in directing the management and leasing activities of the building.
Piedmont 500 W. Monroe Fee, LLC	100%		500 W. Monroe	Consolidated	$	265.2	$	262.4		The Omnibus Agreement with the previous owner includes equity participation rights for the previous owner, if certain financial returns are achieved; however, Piedmont has sole decision making authority and is entitled to 100% of the economic benefits of the property until such returns are met.

- Definition

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

+ References + Details

Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Notional Amounts of Outstanding Derivative Positions

A detail of Piedmont’s interest rate derivatives outstanding as of September 30, 2017 is as follows:

Interest Rate Derivatives:

Number of Swap Agreements

Associated Debt Instrument

Total Notional Amount

(in millions)

Effective Date

Maturity Date

Interest rate swaps

$300 Million Unsecured 2013 Term Loan

200

1/30/2014

1/31/2019

Interest rate swaps

$300 Million Unsecured 2013 Term Loan

100

8/29/2014

1/31/2019

Interest rate swaps

$300 Million Unsecured 2011 Term Loan

300

11/22/2016

1/15/2020

Total

600

Schedule of Interest Rate Derivatives

A detail of Piedmont’s interest rate derivatives on a gross and net basis as of September 30, 2017 and December 31, 2016, respectively, is as follows (in thousands):



Interest rate swaps classified as:	September 30, 2017			December 31, 2016
Gross derivative assets	$	34		$	—
Gross derivative liabilities	(3,915		)	(8,169		)
Net derivative asset/(liability)	$	(3,881	)	$	(8,169	)

Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss)



	Three Months Ended				Nine Months Ended
Interest Rate Swaps in Cash Flow Hedging Relationships	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Amount of gain/(loss) recognized in OCI	$	175	$	2,847	$	307	$	(12,182	)
Amount of previously recorded loss reclassified from accumulated OCI into interest expense	$	653	$	1,045	$	2,936	$	3,291

Fair Value Measurement of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping

The following table sets forth the carrying and estimated fair value for each of Piedmont’s financial instruments, as well as its level within the GAAP fair value hierarchy, as of September 30, 2017 and December 31, 2016, respectively (in thousands):



	September 30, 2017					December 31, 2016
Financial Instrument	Carrying Value		Estimated Fair Value		Level Within Fair Value Hierarchy	Carrying Value		Estimated Fair Value		Level Within Fair Value Hierarchy
Assets:
Cash and cash equivalents⁽¹⁾	$	36,108	$	36,108	Level 1	$	6,992	$	6,992	Level 1
Tenant receivables, net⁽¹⁾	$	12,802	$	12,802	Level 1	$	26,494	$	26,494	Level 1
Restricted cash and escrows⁽¹⁾	$	1,260	$	1,260	Level 1	$	1,212	$	1,212	Level 1
Interest rate swaps	$	34	$	34	Level 2	$	—	$	—	Level 2
Liabilities:
Accounts payable and accrued expenses⁽¹⁾	$	13,465	$	13,465	Level 1	$	44,733	$	44,733	Level 1
Interest rate swaps	$	3,915	$	3,915	Level 2	$	8,169	$	8,169	Level 2
Debt, net	$	1,703,586	$	1,731,584	Level 2	$	2,020,475	$	2,027,436	Level 2


⁽¹⁾	For the periods presented, the carrying value of these financial instruments approximates estimated fair value due to their short-term maturity.

Impairment Loss on Real Estate Assets (Tables)

9 Months Ended

Sep. 30, 2017

Real Estate [Abstract]

Details of Impairment of Long-Lived Assets Held and Used by Asset

Piedmont recorded impairment loss on real estate assets for the three and nine months ended September 30, 2017 and 2016, respectively, as follows (in thousands):



	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
150 West Jefferson⁽¹⁾	$	—	$	—	$	—	$	8,258
9221 Corporate Boulevard ⁽²⁾	—		—		—		2,692
9200 and 9211 Corporate Boulevard⁽³⁾	—		22,951		—		22,951
Total impairment loss on real estate assets⁽⁴⁾	$	—	$	22,951	$	—	$	33,901


⁽¹⁾	Piedmont recognized an impairment loss on real estate assets based upon the difference between the carrying value of the asset and the anticipated contract sales price, less estimated selling costs.

⁽²⁾

⁽³⁾


⁽⁴⁾	The fair value measurements used in the evaluation of the non-financial assets above are considered to be Level 1 valuations within the fair value hierarchy as defined by GAAP, as there are direct observations and transactions involving the assets by unrelated, third-party purchasers.

Details of assets held for sale as of September 30, 2017 and December 31, 2016 are presented below (in thousands):



	September 30, 2017		December 31, 2016
Real estate assets held for sale, net:
Land	$	—	$	52,710
Building and improvements, less accumulated depreciation of $0 and $88,319 as of September 30, 2017 and December 31, 2016, respectively	—		173,218
Construction in progress	—		11
Total real estate assets held for sale, net	$	—	$	225,939

Other assets held for sale, net:
Straight-line rent receivables	$	—	$	2,059
Prepaid expenses and other assets	—		454
Deferred lease costs, less accumulated amortization of $0 and $2,825 as of September 30, 2017 and December 31, 2016, respectively	—		7,302
Total other assets held for sale, net	$	—	$	9,815

Property Dispositions and Assets Held for Sale (Tables)

9 Months Ended

Sep. 30, 2017

Discontinued Operations and Disposal Groups [Abstract]

Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures

Details of such properties sold are presented below (in thousands):



Buildings Sold	Location	Date of Sale	Gain/(Loss) on Sale			Net Sales Proceeds
1055 East Colorado Boulevard	Pasadena, California	April 21, 2016	$	29,461		$	60,076
Fairway Center II	Brea, California	April 28, 2016	$	14,405		$	33,062
1901 Main Street	Irvine, California	May 2, 2016	$	29,964		$	63,149
9221 Corporate Boulevard	Rockville, Maryland	July 27, 2016	$	(192	)	$	12,035
150 West Jefferson	Detroit, Michigan	July 29, 2016	$	(680	)	$	77,827
9200 and 9211 Corporate Boulevard	Rockville, Maryland	September 28, 2016	$	(41	)	$	12,518
Sarasota Commerce Center II	Sarasota, Florida	June 16, 2017	$	6,493		$	23,090
Two Independence Square	Washington, D.C.	July 5, 2017	$	109,516		$	352,180

Details of Impairment of Long-Lived Assets Held and Used by Asset

Piedmont recorded impairment loss on real estate assets for the three and nine months ended September 30, 2017 and 2016, respectively, as follows (in thousands):



	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
150 West Jefferson⁽¹⁾	$	—	$	—	$	—	$	8,258
9221 Corporate Boulevard ⁽²⁾	—		—		—		2,692
9200 and 9211 Corporate Boulevard⁽³⁾	—		22,951		—		22,951
Total impairment loss on real estate assets⁽⁴⁾	$	—	$	22,951	$	—	$	33,901


⁽¹⁾	Piedmont recognized an impairment loss on real estate assets based upon the difference between the carrying value of the asset and the anticipated contract sales price, less estimated selling costs.

⁽²⁾

⁽³⁾


⁽⁴⁾	The fair value measurements used in the evaluation of the non-financial assets above are considered to be Level 1 valuations within the fair value hierarchy as defined by GAAP, as there are direct observations and transactions involving the assets by unrelated, third-party purchasers.

Details of assets held for sale as of September 30, 2017 and December 31, 2016 are presented below (in thousands):



	September 30, 2017		December 31, 2016
Real estate assets held for sale, net:
Land	$	—	$	52,710
Building and improvements, less accumulated depreciation of $0 and $88,319 as of September 30, 2017 and December 31, 2016, respectively	—		173,218
Construction in progress	—		11
Total real estate assets held for sale, net	$	—	$	225,939

Other assets held for sale, net:
Straight-line rent receivables	$	—	$	2,059
Prepaid expenses and other assets	—		454
Deferred lease costs, less accumulated amortization of $0 and $2,825 as of September 30, 2017 and December 31, 2016, respectively	—		7,302
Total other assets held for sale, net	$	—	$	9,815

- Definition

Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=65878427&loc=SL51721533-107759

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721665-107760

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1474-107760

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=64827811&loc=d3e1361-107760

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721683-107760

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=64862545&loc=SL51724579-110230

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5C
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721675-107760

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721663-107760

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64862545&loc=d3e2941-110230

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721659-107760

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5A
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721671-107760

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5D
-URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721677-107760

+ Details

Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Nonvested Share Activity

A rollforward of Piedmont's equity based award activity for the nine months ended September 30, 2017 is as follows:



	Shares		Weighted-Average Grant Date Fair Value
Unvested Stock Awards as of December 31, 2016	944,223		$	19.44
Deferred Stock Awards Granted	299,251		$	21.38
Change in Estimated Potential Future Performance Share Awards, net of forfeitures	(7,828	)	$	23.65
Performance Stock Awards Vested	(118,446	)	$	22.00
Deferred Stock Awards Vested	(302,474	)	$	19.35
Deferred Stock Awards Forfeited	(7,200	)	$	19.79
Unvested Stock Awards as of September 30, 2017	807,526		$	21.39



	Three Months Ended				Nine Months Ended
	September 30, 2017		September 30, 2016		September 30, 2017		September 30, 2016
Weighted-Average Grant Date Fair Value of Deferred Stock Granted During the Period	$	—	$	—	$	21.38	$	19.96
Total Grant Date Fair Value of Deferred Stock Vested During the Period	$	11	$	108	$	5,852	$	4,766
Share-based Liability Awards Paid During the Period⁽¹⁾	$	—	$	—	$	2,877	$	1,127


⁽¹⁾	Amounts reflect the issuance of performance share awards related to the 2014-16 and 2013-15 Performance Share Plans during the nine months ended September 30, 2017 and 2016, respectively.

Schedule of Outstanding Employee Stock Awards

A detail of Piedmont’s outstanding stock awards as of September 30, 2017 is as follows:



Date of grant	Type of Award	Net Shares Granted ⁽¹⁾	Grant Date Fair Value		Vesting Schedule	Unvested Shares as of September 30, 2017
January 3, 2014	Deferred Stock Award	86,769	$	16.56	Of the shares granted, 20% vested or will vest on January 3, 2015, 2016, 2017, 2018, and 2019, respectively.	35,094
May 1, 2015	Deferred Stock Award	216,837	$	17.59	Of the shares granted, 25% vested on the date of grant, and 25% vested or will vest on May 1, 2016, 2017, and 2018, respectively.	67,114
May 1, 2015	Fiscal Year 2015-2017 Performance Share Program	—	$	18.42	Shares awarded, if any, will vest immediately upon determination of award in 2018.	143,846	⁽²⁾
May 24, 2016	Deferred Stock Award	233,011	$	19.91	Of the shares granted, 25% vested on the date of grant, and 25% vested or will vest on May 24, 2017, 2018, and 2019, respectively.	133,092
May 24, 2016	Fiscal Year 2016-2018 Performance Share Program	—	$	23.02	Shares awarded, if any, will vest immediately upon determination of award in 2019.	103,790	⁽²⁾
May 18, 2017	Deferred Stock Award-Board of Directors	26,187	$	21.38	Of the shares granted, 100% will vest by May 18, 2018.	26,187
May 18, 2017	Deferred Stock Award	246,740	$	21.38	Of the shares granted, 25% vested on the date of grant, and 25% vested or will vest on May 18, 2018, 2019, and 2020, respectively.	200,899
May 18, 2017	Fiscal Year 2017-2019 Performance Share Program	—	$	30.45	Shares awarded, if any, will vest immediately upon determination of award in 2020.	97,504	⁽²⁾
Total						807,526


⁽¹⁾	Amounts reflect the total grant to employees and independent directors, net of shares surrendered upon vesting to satisfy required minimum tax withholding obligations through September 30, 2017.


⁽²⁾	Estimated based on Piedmont's cumulative TSR for the respective performance period through September 30, 2017. Share estimates are subject to change in future periods based upon Piedmont's relative performance compared to its peers' total stockholder return.

Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2017

Earnings Per Share [Abstract]

Schedule of Weighted Average Number of Shares



	Three Months Ended		Nine Months Ended
	September 30, 2017	September 30, 2016	September 30, 2017	September 30, 2016
Weighted-average common shares – basic	145,416	145,231	145,372	145,229
Plus: Incremental weighted-average shares from time-vested deferred and performance stock awards	303	438	308	372
Weighted-average common shares – diluted	145,719	145,669	145,680	145,601

Common stock issued and outstanding as of period end			145,295	145,234

Guarantor and Non-Guarantor Financial Information (Tables)

9 Months Ended

Sep. 30, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Condensed Consolidated Balance Sheets



Condensed Consolidated Balance Sheets
As of September 30, 2017
(in thousands)	Issuer		Guarantor			Non-Guarantor Subsidiaries		Eliminations			Consolidated
Assets:
Real estate assets, at cost:
Land	$	43,929	$	—		$	571,005	$	—		$	614,934
Buildings and improvements, less accumulated depreciation	206,700		—			2,516,763		(300		)	2,723,163
Intangible lease assets, less accumulated amortization	317		—			78,383		—			78,700
Construction in progress	797		—			8,160		—			8,957
Total real estate assets	251,743		—			3,174,311		(300		)	3,425,754
Investments in and amounts due from unconsolidated joint ventures	49		—			—		—			49
Cash and cash equivalents	25,884		150			10,074		—			36,108
Tenant and straight-line rent receivables, net	17,556		—			177,855		—			195,411
Advances to affiliates	6,257,405		1,576,739			—		(7,834,144		)	—
Investment in subsidiary	—		3,538,945			177		(3,539,122		)	—
Notes receivable	88,910		—			144,500		(233,410		)	—
Prepaid expenses, restricted cash, escrows, and other assets	4,905		38			25,358		(809		)	29,492
Goodwill	98,918		—			—		—			98,918
Interest rate swaps	34		—			—		—			34
Deferred lease costs, net	13,927		—			260,957		—			274,884
Total assets	$	6,759,331	$	5,115,872		$	3,793,232	$	(11,607,785	)	$	4,060,650
Liabilities:
Debt, net	$	1,511,587	$	—		$	425,409	$	(233,410	)	$	1,703,586
Accounts payable, accrued expenses, and accrued capital expenditures	16,546		652			91,731		(809		)	108,120
Advances from affiliates	790,748		5,226,546			1,915,105		(7,932,399		)	—
Deferred income	3,728		—			26,242		—			29,970
Intangible lease liabilities, net	—		—			41,064		—			41,064
Interest rate swaps	3,915		—			—		—			3,915
Total liabilities	2,326,524		5,227,198			2,499,551		(8,166,618		)	1,886,655
Stockholders’ Equity:
Common stock	—		1,453			—		—			1,453
Additional paid-in capital	3,534,946		3,679,578			1,304		(3,539,122		)	3,676,706
Retained/(cumulative distributions in excess of) earnings	892,461		(3,792,357		)	1,290,513		97,955			(1,511,428		)
Other comprehensive loss	5,400		—			—		—			5,400
Piedmont stockholders’ equity	4,432,807		(111,326		)	1,291,817		(3,441,167		)	2,172,131
Noncontrolling interest	—		—			1,864		—			1,864
Total stockholders’ equity	4,432,807		(111,326		)	1,293,681		(3,441,167		)	2,173,995
Total liabilities and stockholders’ equity	$	6,759,331	$	5,115,872		$	3,793,232	$	(11,607,785	)	$	4,060,650



Condensed Consolidated Balance Sheets
As of December 31, 2016
(in thousands)	Issuer		Guarantor			Non-Guarantor Subsidiaries		Eliminations			Consolidated
Assets:
Real estate assets, at cost:
Land	$	46,133	$	—		$	571,005	$	—		$	617,138
Buildings and improvements, less accumulated depreciation	228,194		—			2,526,212		(300		)	2,754,106
Intangible lease assets, less accumulated amortization	725		—			98,970		—			99,695
Construction in progress	145		—			34,669		—			34,814
Real estate assets held for sale, net	—		—			225,939		—			225,939
Total real estate assets	275,197		—			3,456,795		(300		)	3,731,692
Investments in and amounts due from unconsolidated joint ventures	7,360		—			—		—			7,360
Cash and cash equivalents	3,674		150			3,168		—			6,992
Tenant and straight-line rent receivables, net	20,159		—			170,124		—			190,283
Advances to affiliates	6,464,135		1,315,616			—		(7,779,751		)	—
Investment in subsidiary	—		3,630,564			181		(3,630,745		)	—
Notes receivable	88,910		—			95,790		(184,700		)	—
Prepaid expenses, restricted cash, escrows, and other assets	6,189		—			20,121		(1,897		)	24,413
Goodwill	98,918		—			—		—			98,918
Deferred lease costs, net	16,550		—			282,145		—			298,695
Other assets held for sale, net	—		—			9,815		—			9,815
Total assets	$	6,981,092	$	4,946,330		$	4,038,139	$	(11,597,393	)	$	4,368,168
Liabilities:
Debt, net	$	1,701,933	$	—		$	503,242	$	(184,700	)	$	2,020,475
Accounts payable, accrued expenses, and accrued capital expenditures	17,365		31,230			118,712		(1,897		)	165,410
Advances from affiliates	708,340		5,071,521			2,098,146		(7,878,007		)	—
Deferred income	5,206		—			23,200		—			28,406
Intangible lease liabilities, net	—		—			48,005		—			48,005
Interest rate swaps	8,169		—			—		—			8,169
Total liabilities	2,441,013		5,102,751			2,791,305		(8,064,604		)	2,270,465
Stockholders’ Equity:
Common stock	—		1,452			—		—			1,452
Additional paid-in capital	3,626,564		3,676,000			1,309		(3,630,745		)	3,673,128
Retained/(cumulative distributions in excess of) earnings	911,411		(3,833,873		)	1,243,643		97,956			(1,580,863		)
Other comprehensive income	2,104		—			—		—			2,104
Piedmont stockholders’ equity	4,540,079		(156,421		)	1,244,952		(3,532,789		)	2,095,821
Noncontrolling interest	—		—			1,882		—			1,882
Total stockholders’ equity	4,540,079		(156,421		)	1,246,834		(3,532,789		)	2,097,703
Total liabilities and stockholders’ equity	$	6,981,092	$	4,946,330		$	4,038,139	$	(11,597,393	)	$	4,368,168

Condensed Consolidated Statements of Income



Condensed Consolidated Statements of Income
For the three months ended September 30, 2017
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	10,232		$	—		$	103,544		$	(426	)	$	113,350
Tenant reimbursements	2,376			—			21,562			(142		)	23,796
Property management fee revenue	—			—			4,553			(4,112		)	441
	12,608			—			129,659			(4,680		)	137,587
Expenses:
Property operating costs	5,372			—			53,398			(4,680		)	54,090
Depreciation	3,199			—			26,801			—			30,000
Amortization	740			—			17,383			—			18,123
General and administrative	1,539			77			5,002			—			6,618
	10,850			77			102,584			(4,680		)	108,831
Real estate operating income/(loss)	1,758			(77		)	27,075			—			28,756
Other income (expense):
Interest expense	(13,795		)	—			(6,354		)	3,966			(16,183		)
Other income/(expense)	2,404			—			1,852			(3,966		)	290
Equity in income of unconsolidated joint ventures	3,754			—			—			—			3,754
	(7,637		)	—			(4,502		)	—			(12,139		)
Income/(loss) from continuing operations	(5,879		)	(77		)	22,573			—			16,617
Discontinued operations:
Operating income	—			—			—			—			—
Income from discontinued operations	—			—			—			—			—
Gain/(loss) on sale of real estate assets, net	(4		)	—			109,516			—			109,512
Net income/(loss)	(5,883		)	(77		)	132,089			—			126,129
Plus: Net income applicable to noncontrolling interest	—			—			4			—			4
Net income/(loss) applicable to Piedmont	$	(5,883	)	$	(77	)	$	132,093		$	—		$	126,133



Condensed Consolidated Statements of Income
For the three months ended September 30, 2016
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	12,862		$	—		$	101,423		$	(464	)	$	113,821
Tenant reimbursements	3,430			—			20,970			(237		)	24,163
Property management fee revenue	—			—			3,985			(3,484		)	501
	16,292			—			126,378			(4,185		)	138,485
Expenses:
Property operating costs	7,820			—			51,287			(4,240		)	54,867
Depreciation	3,617			—			27,993			—			31,610
Amortization	863			—			17,777			—			18,640
Impairment loss on real estate assets	—			—			22,951			—			22,951
General and administrative	7,187			83			9,016			(8,857		)	7,429
	19,487			83			129,024			(13,097		)	135,497
Real estate operating income/(loss)	(3,195		)	(83		)	(2,646		)	8,912			2,988
Other income (expense):
Interest expense	(11,799		)	—			(6,949		)	3,252			(15,496		)
Other income/(expense)	2,608			—			(76		)	(3,252		)	(720		)
Net recoveries from casualty events	—			—			34			—			34
Equity in income of unconsolidated joint ventures	129			—			—			—			129
	(9,062		)	—			(6,991		)	—			(16,053		)
Income/(loss) from continuing operations	(12,257		)	(83		)	(9,637		)	8,912			(13,065		)
Discontinued operations:
Operating income	—			—			1			—			1
Income from discontinued operations	—			—			1			—			1
Gain/(loss) on sale of real estate assets, net	134			—			(191		)	—			(57		)
Net income/(loss)	(12,123		)	(83		)	(9,827		)	8,912			(13,121		)
Plus: Net income applicable to noncontrolling interest	—			—			14			—			14
Net income/(loss) applicable to Piedmont	$	(12,123	)	$	(83	)	$	(9,813	)	$	8,912		$	(13,107	)



Condensed Consolidated Statements of Income
For the nine months ended September 30, 2017
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	32,749		$	—		$	329,669		$	(1,370	)	$	361,048
Tenant reimbursements	8,341			—			64,372			(373		)	72,340
Property management fee revenue	—			—			13,753			(12,412		)	1,341
	41,090			—			407,794			(14,155		)	434,729
Expenses:
Property operating costs	17,027			—			162,381			(14,155		)	165,253
Depreciation	9,943			—			80,884			—			90,827
Amortization	2,399			—			55,453			—			57,852
General and administrative	4,798			261			18,191			—			23,250
	34,167			261			316,909			(14,155		)	337,182
Real estate operating income/(loss)	6,923			(261		)	90,885			—			97,547
Other income (expense):
Interest expense	(43,049		)	—			(20,868		)	11,256			(52,661		)
Other income/(expense)	6,873			—			4,611			(11,256		)	228
Equity in income of unconsolidated joint ventures	3,872			—			—			—			3,872
	(32,304		)	—			(16,257		)	—			(48,561		)
Income/(loss) from continuing operations	(25,381		)	(261		)	74,628			—			48,986
Discontinued operations:
Operating income	—			—			—			—			—
Income from discontinued operations	—			—			—			—			—
Gain on sale of real estate assets, net	6,430			—			109,521			—			115,951
Net income/(loss)	(18,951		)	(261		)	184,149			—			164,937
Plus: Net income applicable to noncontrolling interest	—			—			10			—			10
Net income/(loss) applicable to Piedmont	$	(18,951	)	$	(261	)	$	184,159		$	—		$	164,947



Condensed Consolidated Statements of Income
For the nine months ended September 30, 2016
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Revenues:
Rental income	$	42,990		$	—		$	299,319		$	(1,983	)	$	340,326
Tenant reimbursements	10,455			—			59,950			(405		)	70,000
Property management fee revenue	—			—			12,480			(11,002		)	1,478
	53,445			—			371,749			(13,390		)	411,804
Expenses:
Property operating costs	24,583			—			150,369			(13,514		)	161,438
Depreciation	12,993			—			81,955			—			94,948
Amortization	2,854			—			50,994			—			53,848
Impairment loss of real estate assets	8,259			—			25,642			—			33,901
General and administrative	22,802			251			28,881			(28,416		)	23,518
	71,491			251			337,841			(41,930		)	367,653
Real estate operating income/(loss)	(18,046		)	(251		)	33,908			28,540			44,151
Other income (expense):
Interest expense	(36,159		)	—			(20,354		)	8,219			(48,294		)
Other income/(expense)	7,008			282			462			(8,219		)	(467		)
Net recoveries from casualty events	—			—			34			—			34
Equity in income of unconsolidated joint ventures	354			—			—			—			354
	(28,797		)	282			(19,858		)	—			(48,373		)
Net income/(loss)	(46,843		)	31			14,050			28,540			(4,222		)
Discontinued operations:
Operating income	—			—			—			—			—
Income from discontinued operations	—			—			—			—			—
Gain on sale of real estate assets, net	30,096			—			43,662			—			73,758
Net income/(loss)	(16,747		)	31			57,712			28,540			69,536
Plus: Net income applicable to noncontrolling interest	—			—			7			—			7
Net income/(loss) applicable to Piedmont	$	(16,747	)	$	31		$	57,719		$	28,540		$	69,543

Condensed Consolidated Statements of Cash Flows



Condensed Consolidated Statements of Cash Flows
For the nine months ended September 30, 2017
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Net Cash Provided by/(Used in) Operating Activities	$	(15,467	)	$	4,335		$	187,464		$	—		$	176,332

Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	(793		)	—			(64,614		)	—			(65,407		)
Intercompany note receivable	—			—			(48,710		)	48,710			—
Net sales proceeds from wholly-owned properties	23,028			—			352,171			—			375,199
Net sales proceeds received from unconsolidated joint ventures	12,334			—			—			—			12,334
Investments in unconsolidated joint ventures	(1,162		)	—			—			—			(1,162		)
Deferred lease costs paid	(858		)	—			(18,561		)	—			(19,419		)
Net cash provided by investing activities	32,549			—			220,286			48,710			301,545
Cash Flows from Financing Activities:
Debt issuance costs paid	(102		)	—			1			—			(101		)
Proceeds from debt	147,000			—			—			—			147,000
Repayments of debt	(325,000		)	—			(141,046		)	—			(466,046		)
Intercompany note payable	(14,289		)	—			62,999			(48,710		)	—
Costs of issuance of common stock	—			(97		)	—			—			(97		)
Value of shares withheld to pay tax obligations related to employee stock compensation	—			(3,385		)	—			—			(3,385		)
Repurchases of common stock as part of announced plan	—			(3,895		)	—			—			(3,895		)
(Distributions to)/repayments from affiliates	197,519			125,271			(322,790		)	—			—
Dividends paid and discount on dividend reinvestments	—			(122,229		)	(8		)	—			(122,237		)
Net cash used in financing activities	5,128			(4,335		)	(400,844		)	(48,710		)	(448,761		)
Net increase in cash and cash equivalents	22,210			—			6,906			—			29,116
Cash and cash equivalents, beginning of period	3,674			150			3,168			—			6,992
Cash and cash equivalents, end of period	$	25,884		$	150		$	10,074		$	—		$	36,108



Condensed Consolidated Statements of Cash Flows
For the nine months ended September 30, 2016
(in thousands)	Issuer			Guarantor			Non-Guarantor Subsidiaries			Eliminations			Consolidated
Net Cash Provided by/(Used in) Operating Activities	$	(18,977	)	$	4,121		$	158,352		$	28,540		$	172,036

Cash Flows from Investing Activities:
Investment in real estate assets, consolidated joint venture, and real estate related intangibles, net of accruals	(24,255		)	—			(296,884		)	—			(321,139		)
Intercompany note receivable	440			—			(71,900		)	71,460			—
Net sales proceeds from wholly-owned properties	187,192			—			117,710			—			304,902
Deferred lease costs paid	(2,021		)	—			(13,324		)	—			(15,345		)
Net cash provided by/(used in) investing activities	161,356			—			(264,398		)	71,460			(31,582		)
Cash Flows from Financing Activities:
Debt issuance costs paid	(212		)	—			—			—			(212		)
Proceeds from debt	552,000			—			—			—			552,000
Repayments of debt	(421,000		)	—			(168,532		)	—			(589,532		)
Intercompany note payable	(9,600		)	—			81,060			(71,460		)	—
Costs of issuance of common stock	—			(239		)	—			—			(239		)
Value of shares withheld to pay tax obligations related to employee stock compensation	—			(2,328		)	—			—			(2,328		)
Repurchases of common stock as part of announced plan	—			(7,943		)	—			—			(7,943		)
(Distributions to)/repayments from affiliates	(262,150		)	97,990			192,700			(28,540		)	—
Dividends paid and discount on dividend reinvestments	—			(91,601		)	(8		)	—			(91,609		)
Net cash provided by/(used in) financing activities	(140,962		)	(4,121		)	105,220			(100,000		)	(139,863		)
Net increase/(decrease) in cash and cash equivalents	1,417			—			(826		)	—			591
Cash and cash equivalents, beginning of period	2,174			150			3,117			—			5,441
Cash and cash equivalents, end of period	$	3,591		$	150		$	2,291		$	—		$	6,032

Organization (Details) ft² in Millions	9 Months Ended
Organization (Details) ft² in Millions	Sep. 30, 2017 ft² segment property subsidiary market
Real Estate Properties [Line Items]
Number of wholly-owned subsidiaries \| subsidiary	2
Percentage ownership by sole general partner	99.90%
Percentage ownership by sole limited partner	0.10%
Percentage of annualized lease revenue	88.00%
Number of operating segments \| segment	1
U.S.
Real Estate Properties [Line Items]
Number of major U.S. office markets \| market	8
In Service Office Properties
Real Estate Properties [Line Items]
Number of real estate properties \| property	66
Square footage of real estate property \| ft²	19
Percentage leased	89.20%

Summary of Significant Accounting Policies (Details)	9 Months Ended
Summary of Significant Accounting Policies (Details)	Sep. 30, 2017
Total Revenues Derived from Long Term Leases to Tenants or Reimbursement of Property Tax and Insurance Expenses \| Sales Revenue, Net
Concentration Risk [Line Items]
Percentage of total revenues	90.00%

Debt (Details)		9 Months Ended
Debt (Details)	Aug. 01, 2017 USD ($)	Sep. 30, 2017 USD ($) period	Jul. 05, 2017 USD ($)	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
Weighted average rate		3.47%
Amount Outstanding		$ 1,703,586,000		$ 2,020,475,000
Secured Debt
Debt Instrument [Line Items]
Weighted average rate		3.82%
Amount Outstanding		$ 191,923,000		332,744,000
Net premium, discounts, and unamortized debt issuance costs		1,020,000		1,161,000
Secured Debt \| $140 Million WDC Fixed-Rate Loans
Debt Instrument [Line Items]
Face amount of debt instrument		$ 140,000,000
Stated Rate		5.76%
Effective interest rate		5.76%
Amount Outstanding		$ 0		140,000,000
Amount fully repaid	$ 140,000,000
Secured Debt \| $35 Million Fixed-Rate Loan
Debt Instrument [Line Items]
Face amount of debt instrument		$ 35,000,000
Stated Rate		5.55%
Effective interest rate		3.75%
Amount Outstanding		$ 30,903,000		31,583,000
Secured Debt \| $160 Million Fixed Rate Loan
Debt Instrument [Line Items]
Face amount of debt instrument		$ 160,000,000
Stated Rate		3.48%
Effective interest rate		3.58%
Amount Outstanding		$ 160,000,000		160,000,000
Unsecured Debt
Debt Instrument [Line Items]
Weighted average rate		3.43%
Amount Outstanding		$ 1,511,663,000		1,687,731,000
Net premium, discounts, and unamortized debt issuance costs		(8,337,000)		(10,269,000)
Unsecured Debt \| $170 Million Unsecured 2015 Term Loan
Debt Instrument [Line Items]
Face amount of debt instrument		$ 170,000,000
Effective interest rate		2.37%
Amount Outstanding		$ 170,000,000		170,000,000
Unsecured Debt \| $170 Million Unsecured 2015 Term Loan \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		1.125%
Unsecured Debt \| $300 Million Unsecured 2013 Term Loan
Debt Instrument [Line Items]
Face amount of debt instrument		$ 300,000,000
Amount Outstanding		$ 300,000,000		300,000,000
Unsecured Debt \| $300 Million Unsecured 2013 Term Loan \| Interest rate swaps
Debt Instrument [Line Items]
Effective interest rate		2.78%
Unsecured Debt \| $300 Million Unsecured 2013 Term Loan \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		1.20%
Unsecured Debt \| $500 Million Unsecured 2015 Line of Credit \| Line of Credit
Debt Instrument [Line Items]
Face amount of debt instrument		$ 500,000,000
Effective interest rate		0.00%
Amount Outstanding		$ 0		178,000,000
Maximum extension period		1 year
Number of extension periods \| period		2
Extension period		6 months
Amount of line of credit			$ 500,000,000
Unsecured Debt \| $500 Million Unsecured 2015 Line of Credit \| Line of Credit \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
Unsecured Debt \| $300 Million Unsecured 2011 Term Loan
Debt Instrument [Line Items]
Face amount of debt instrument		$ 300,000,000
Amount Outstanding		$ 300,000,000		300,000,000
Unsecured Debt \| $300 Million Unsecured 2011 Term Loan \| Interest rate swaps
Debt Instrument [Line Items]
Effective interest rate		3.35%
Unsecured Debt \| $300 Million Unsecured 2011 Term Loan \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate		1.15%
Unsecured Debt \| $350 Million Senior Notes
Debt Instrument [Line Items]
Face amount of debt instrument		$ 350,000,000
Stated Rate		3.40%
Effective interest rate		3.43%
Amount Outstanding		$ 350,000,000		350,000,000
Unsecured Debt \| $400 Million Senior Notes
Debt Instrument [Line Items]
Face amount of debt instrument		$ 400,000,000
Stated Rate		4.45%
Effective interest rate		4.10%
Amount Outstanding		$ 400,000,000		$ 400,000,000

Debt (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Debt (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Debt Disclosure [Abstract]
Interest payments on debt facilities	$ 18,000	$ 18,500	$ 54,000	$ 53,200
Capitalized interest	$ 37	$ 1,500	$ 200	$ 3,400

Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Eye Street 1201 N.W. Associates LLC
Variable Interest Entity [Line Items]
Piedmont’s % Ownership of Entity			98.60%
Net Carrying Amount	$ 82.1		$ 82.1	$ (6.7)
Primary Beneficiary Considerations, percentage of cash flow and economic benefits	100.00%		100.00%
Eye Street 1225 N.W. Associates LLC
Variable Interest Entity [Line Items]
Piedmont’s % Ownership of Entity			98.10%
Net Carrying Amount	$ 66.2		$ 66.2	9.9
Primary Beneficiary Considerations, percentage of cash flow and economic benefits	100.00%		100.00%
Piedmont 500 W. Monroe Fee LLC
Variable Interest Entity [Line Items]
Piedmont’s % Ownership of Entity			100.00%
Net Carrying Amount	$ 265.2		$ 265.2	$ 262.4
Primary Beneficiary Considerations, percentage of cash flow and economic benefits	100.00%		100.00%
Eye Street 1201 NW Associates LLC and Eye Street 1225, NW Associates LLC [Member]
Variable Interest Entity [Line Items]
Piedmont’s % Ownership of Entity		49.50%
Repayment of secured mortgage	$ 140.0

Derivative Instruments (Details)	3 Months Ended		9 Months Ended
Derivative Instruments (Details)	Sep. 30, 2017 USD ($) contract	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) contract	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Derivative [Line Items]
Maximum period of extension term			27 months
Interest Rate Cash Flow Hedge Derivative at Fair Value, Net [Abstract]
Gross derivative assets	$ (34,000)		$ (34,000)		$ 0
Gross derivative liabilities	(3,915,000)		(3,915,000)		(8,169,000)
Net derivative asset/(liability)	(3,881,000)		(3,881,000)		$ (8,169,000)
Loss to be reclassified from accumulated other comprehensive loss to interest expense over next twelve months	1,200,000		1,200,000
Loss related to hedge ineffectiveness and terminations of cash flow hedges	0	$ 0	0	$ 0
Interest rate swaps
Derivative [Line Items]
Total notional value	600,000,000		600,000,000
Interest rate swaps \| Interest Expense
Interest Rate Cash Flow Hedge Derivative at Fair Value, Net [Abstract]
Amount of gain/(loss) recognized in OCI	175,000	2,847,000	307,000	(12,182,000)
Amount of previously recorded loss reclassified from accumulated OCI into interest expense	653,000	$ 1,045,000	2,936,000	$ 3,291,000
Credit Risk Contract
Interest Rate Cash Flow Hedge Derivative at Fair Value, Net [Abstract]
Assets needed for immediate settlement, aggregate fair value	4,000,000		4,000,000
Unsecured Debt \| $300 Million Unsecured 2013 Term Loan
Derivative [Line Items]
Face amount of debt instrument	$ 300,000,000		$ 300,000,000
Unsecured Debt \| $300 Million Unsecured 2013 Term Loan \| Interest Rate Swap 1 through 4
Derivative [Line Items]
Number of Swap Agreements \| contract	4		4
Total notional value	$ 200,000,000		$ 200,000,000
Unsecured Debt \| $300 Million Unsecured 2013 Term Loan \| Interest Rate Swap 5 through 6
Derivative [Line Items]
Number of Swap Agreements \| contract	2		2
Total notional value	$ 100,000,000		$ 100,000,000
Unsecured Debt \| $300 Million Unsecured 2011 Term Loan
Derivative [Line Items]
Face amount of debt instrument	$ 300,000,000		$ 300,000,000
Unsecured Debt \| $300 Million Unsecured 2011 Term Loan \| Interest Rate Swap 7 through 9
Derivative [Line Items]
Number of Swap Agreements \| contract	3		3
Total notional value	$ 300,000,000		$ 300,000,000

Fair Value Measurement of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	$ 34	$ 0
Interest rate swaps	3,915	8,169
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	36,108	6,992
Restricted cash and escrows	1,260	1,212
Accounts payable and accrued expenses	13,465	44,733
Debt, net	1,703,586	2,020,475
Interest rate swaps \| Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	34	0
Interest rate swaps	3,915	8,169
Tenant receivables, net \| Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Tenant receivables, net	12,802	26,494
Level 1 \| Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	36,108	6,992
Restricted cash and escrows	1,260	1,212
Accounts payable and accrued expenses	13,465	44,733
Level 1 \| Tenant receivables, net \| Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Tenant receivables, net	12,802	26,494
Level 2 \| Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, net	1,731,584	2,027,436
Level 2 \| Interest rate swaps \| Estimated Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swaps	34	0
Interest rate swaps	$ 3,915	$ 8,169

Impairment Loss on Real Estate Assets (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jul. 31, 2016 property
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment loss on real estate assets	$ 0	$ 22,951	$ 0	$ 33,901
Disposal Group, Held-for-sale, Not Discontinued Operations \| 150 West Jefferson
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment loss on real estate assets	0	0	0	8,258
Disposal Group, Held-for-sale, Not Discontinued Operations \| 9200 and 9211 Corporate Boulevard
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment loss on real estate assets	0	22,951	0	22,951
Number of real estate properties sold \| property					2
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| 9221 Corporate Boulevard
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment loss on real estate assets	$ 0	$ 0	$ 0	2,692
Impairment loss				2,700
Disposal Group, Disposed of by Sale, Not Discontinued Operations \| 9200 and 9211 Corporate Boulevard
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment loss				$ 23,000

Commitments and Contingencies (Details)	3 Months Ended		9 Months Ended
Commitments and Contingencies (Details)	Sep. 30, 2017 USD ($) category	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) category	Sep. 30, 2016 USD ($)
Loss Contingencies [Line Items]
Number of tenant and building improvement categories \| category	2		2
Collectibility of Tenant Reimbursements
Loss Contingencies [Line Items]
Reductions in reimbursement revenues	$ 0	$ 0	$ 300,000	$ 0
Non-Incremental Capital Expenditures
Loss Contingencies [Line Items]
Period for commitments for funding non-incremental capital expenditures			5 years
Potential obligations for tenant improvements	32,100,000		$ 32,100,000
Non-Incremental Capital Expenditures \| Maximum
Loss Contingencies [Line Items]
Period for commitments for funding non-incremental capital expenditures			3 years
Incremental Capital Expenditures
Loss Contingencies [Line Items]
Potential obligations for tenant improvements	$ 15,200,000		$ 15,200,000

Property Dispositions and Assets Held for Sale (Property Dispositions) (Details) - Disposal Group, Disposed of by Sale, Not Discontinued Operations - USD ($) $ in Thousands	Jul. 05, 2017	Jun. 16, 2017	Sep. 28, 2016	Jul. 29, 2016	Jul. 27, 2016	May 02, 2016	Apr. 28, 2016	Apr. 21, 2016
1055 East Colorado Boulevard
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale								$ 29,461
Net Sales Proceeds								$ 60,076
Fairway Center II
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale							$ 14,405
Net Sales Proceeds							$ 33,062
1901 Main Street
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale						$ 29,964
Net Sales Proceeds						$ 63,149
9221 Corporate Boulevard
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale					$ (192)
Net Sales Proceeds					$ 12,035
150 West Jefferson
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale				$ (680)
Net Sales Proceeds				$ 77,827
9200 and 9211 Corporate Boulevard
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale			$ (41)
Net Sales Proceeds			$ 12,518
Sarasota Commerce Center II
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale		$ 6,493
Net Sales Proceeds		$ 23,090
Two Independence Square
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain/(Loss) on Sale	$ 109,516
Net Sales Proceeds	$ 352,180

Property Dispositions and Assets Held for Sale (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales proceeds from equity method investment		$ 12,334	$ 0
8560 Upland Drive building \| Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percent of interest sold	72.00%	72.00%
Amount of investment sold	$ 12,700
Net sales proceeds from equity method investment	12,300
Gain on sale of equity method investment	$ 3,700

Property Dispositions and Assets Held for Sale (Assets Held-for-Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total other assets held for sale, net	$ 0	$ 9,815
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total real estate assets held for sale, net	0	225,939
Straight-line rent receivables	0	2,059
Prepaid expenses and other assets	0	454
Deferred lease costs, less accumulated amortization of $0 and $2,825 as of September 30, 2017 and December 31, 2016, respectively	0	7,302
Accumulated amortization on deferred lease costs	0	2,825
Total other assets held for sale, net	0	9,815
Disposal Group, Held-for-sale, Not Discontinued Operations \| Land
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate assets held for sale, net:	0	52,710
Disposal Group, Held-for-sale, Not Discontinued Operations \| Building and building improvements
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate assets held for sale, net:	0	173,218
Accumulated depreciation (building improvements)	0	88,319
Disposal Group, Held-for-sale, Not Discontinued Operations \| Construction in progress
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Real estate assets held for sale, net:	$ 0	$ 11

Stock Based Compensation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to stock awards	$ 1.3	$ 2.0	$ 7.0	$ 7.7
Amortization of unvested shares			$ 5.2	$ 6.2
Total shares issued to employees, directors, and officers (in shares)			254,873
Unrecognized compensation cost related to nonvested	$ 5.1		$ 5.1
Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested, weighted-average vesting period			1 year
Stock Awards \| Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			1 year

Stock Based Compensation (Rollforward of Stock Awards) (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Unvested Stock Awards, Beginning of period (in shares)			944,223
Unvested Stock Awards, End of period (in shares)	807,526		807,526
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Unvested Stock Awards, Weighted-Average Grant Date Fair Value, Beginning of period (in dollars per share)			$ 19.44
Unvested Stock Awards, Weighted-Average Grant Date Fair Value, End of period (in dollars per share)	$ 21.39		$ 21.39
Deferred Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Deferred Stock Awards Granted (in shares)			299,251
Performance Stock Awards and Deferred Stock Awards Vested (in shares)			(302,474)
Deferred Stock Awards Forfeited (in shares)			(7,200)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Deferred Stock Awards Granted, Weighted-Average Grant Date Fair Value (in dollars per share)	$ 0.00	$ 0.00	$ 21.38	$ 19.96
Performance Stock Awards and Deferred Stock Awards Vested, Weighted-Average Grant Date Fair Value (in dollars per share)			19.35
Deferred Stock Awards Forfeited, Weighted-Average Grant Date Fair Value (in dollars per share)			$ 19.79
Performance Share Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Change in Estimated Potential Future Performance Share Awards, net of forfeitures (in shares)			(7,828)
Performance Stock Awards and Deferred Stock Awards Vested (in shares)			(118,446)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Change in Estimated Potential Future Performance Share Awards, net of forfeitures, Weighted-Average Grant Date Fair Value (in dollars per share)			$ 23.65
Performance Stock Awards and Deferred Stock Awards Vested, Weighted-Average Grant Date Fair Value (in dollars per share)			$ 22.00

Stock Based Compensation (Additional Information Regarding Stock Award Activity) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Deferred Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value of Deferred Stock Granted During the Period (in dollars per share)	$ 0.00	$ 0.00	$ 21.38	$ 19.96
Total Grant Date Fair Value of Deferred Stock Vested During the Period	$ 11	$ 108	$ 5,852	$ 4,766
Performance Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Liability Awards Paid During the Period	$ 0	$ 0	$ 2,877	$ 1,127

Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
Earnings Per Share (Details) - shares	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Earnings Per Share [Abstract]
Weighted-average common shares outstanding – basic (in shares)	145,415,678	145,231,160	145,372,182	145,228,755
Plus: Incremental weighted-average shares from time-vested deferred and performance stock awards (in shares)	303,000	438,000	308,000	372,000
Weighted-average common shares outstanding – diluted (in shares)	145,719,431	145,669,237	145,679,582	145,601,026
Common stock, shares issued (in shares)	145,294,845	145,234,000	145,294,845	145,234,000	145,235,313
Common stock, shares outstanding (in shares)	145,294,845	145,234,000	145,294,845	145,234,000	145,235,313

Guarantor and Non-Guarantor Financial Information (Condensed Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Assets:
Land	$ 614,934	$ 617,138
Buildings and improvements, less accumulated depreciation	2,723,163	2,754,106
Intangible lease assets, less accumulated amortization	78,700	99,695
Construction in progress	8,957	34,814
Real estate assets held for sale, net	0	225,939
Total real estate assets	3,425,754	3,731,692
Investments in and amounts due from unconsolidated joint ventures	49	7,360
Cash and cash equivalents	36,108	6,992	$ 6,032	$ 5,441
Tenant and straight-line rent receivables, net	195,411	190,283
Advances to affiliates	0	0
Investment in subsidiary	0	0
Note receivable	0	0
Prepaid expenses, restricted cash, escrows, and other assets	29,492	24,413
Goodwill	98,918	98,918
Interest rate swaps	34	0
Deferred lease costs, net	274,884	298,695
Other assets held for sale, net	0	9,815
Total assets	4,060,650	4,368,168
Liabilities:
Debt, net	1,703,586	2,020,475
Accounts payable, accrued expenses, and accrued capital expenditures	108,120	165,410
Advances from affiliates	0	0
Deferred income	29,970	28,406
Intangible lease liabilities, net	41,064	48,005
Interest rate swaps	3,915	8,169
Total liabilities	1,886,655	2,270,465
Stockholders’ Equity:
Common stock	1,453	1,452
Additional paid-in capital	3,676,706	3,673,128
Cumulative distributions in excess of earnings	(1,511,428)	(1,580,863)
Other comprehensive loss income	5,400	2,104
Piedmont stockholders’ equity	2,172,131	2,095,821
Noncontrolling interest	1,864	1,882
Total stockholders’ equity	2,173,995	2,097,703		2,123,420
Total liabilities and stockholders’ equity	4,060,650	4,368,168
Eliminations
Assets:
Land	0	0
Buildings and improvements, less accumulated depreciation	(300)	(300)
Intangible lease assets, less accumulated amortization	0	0
Construction in progress	0	0
Real estate assets held for sale, net		0
Total real estate assets	(300)	(300)
Investments in and amounts due from unconsolidated joint ventures	0	0
Cash and cash equivalents	0	0	0	0
Tenant and straight-line rent receivables, net	0	0
Advances to affiliates	(7,834,144)	(7,779,751)
Investment in subsidiary	(3,539,122)	(3,630,745)
Note receivable	(233,410)	(184,700)
Prepaid expenses, restricted cash, escrows, and other assets	(809)	(1,897)
Goodwill	0	0
Interest rate swaps	0
Deferred lease costs, net	0	0
Other assets held for sale, net		0
Total assets	(11,607,785)	(11,597,393)
Liabilities:
Debt, net	(233,410)	(184,700)
Accounts payable, accrued expenses, and accrued capital expenditures	(809)	(1,897)
Advances from affiliates	(7,932,399)	(7,878,007)
Deferred income	0	0
Intangible lease liabilities, net	0	0
Interest rate swaps	0	0
Total liabilities	(8,166,618)	(8,064,604)
Stockholders’ Equity:
Common stock	0	0
Additional paid-in capital	(3,539,122)	(3,630,745)
Cumulative distributions in excess of earnings	97,955	97,956
Other comprehensive loss income	0	0
Piedmont stockholders’ equity	(3,441,167)	(3,532,789)
Noncontrolling interest	0	0
Total stockholders’ equity	(3,441,167)	(3,532,789)
Total liabilities and stockholders’ equity	(11,607,785)	(11,597,393)
Issuer
Assets:
Land	43,929	46,133
Buildings and improvements, less accumulated depreciation	206,700	228,194
Intangible lease assets, less accumulated amortization	317	725
Construction in progress	797	145
Real estate assets held for sale, net		0
Total real estate assets	251,743	275,197
Investments in and amounts due from unconsolidated joint ventures	49	7,360
Cash and cash equivalents	25,884	3,674	3,591	2,174
Tenant and straight-line rent receivables, net	17,556	20,159
Advances to affiliates	6,257,405	6,464,135
Investment in subsidiary	0	0
Note receivable	88,910	88,910
Prepaid expenses, restricted cash, escrows, and other assets	4,905	6,189
Goodwill	98,918	98,918
Interest rate swaps	34
Deferred lease costs, net	13,927	16,550
Other assets held for sale, net		0
Total assets	6,759,331	6,981,092
Liabilities:
Debt, net	1,511,587	1,701,933
Accounts payable, accrued expenses, and accrued capital expenditures	16,546	17,365
Advances from affiliates	790,748	708,340
Deferred income	3,728	5,206
Intangible lease liabilities, net	0	0
Interest rate swaps	3,915	8,169
Total liabilities	2,326,524	2,441,013
Stockholders’ Equity:
Common stock	0	0
Additional paid-in capital	3,534,946	3,626,564
Cumulative distributions in excess of earnings	892,461	911,411
Other comprehensive loss income	5,400	2,104
Piedmont stockholders’ equity	4,432,807	4,540,079
Noncontrolling interest	0	0
Total stockholders’ equity	4,432,807	4,540,079
Total liabilities and stockholders’ equity	6,759,331	6,981,092
Guarantor
Assets:
Land	0	0
Buildings and improvements, less accumulated depreciation	0	0
Intangible lease assets, less accumulated amortization	0	0
Construction in progress	0	0
Real estate assets held for sale, net		0
Total real estate assets	0	0
Investments in and amounts due from unconsolidated joint ventures	0	0
Cash and cash equivalents	150	150	150	150
Tenant and straight-line rent receivables, net	0	0
Advances to affiliates	1,576,739	1,315,616
Investment in subsidiary	3,538,945	3,630,564
Note receivable	0	0
Prepaid expenses, restricted cash, escrows, and other assets	38	0
Goodwill	0	0
Interest rate swaps	0
Deferred lease costs, net	0	0
Other assets held for sale, net		0
Total assets	5,115,872	4,946,330
Liabilities:
Debt, net	0	0
Accounts payable, accrued expenses, and accrued capital expenditures	652	31,230
Advances from affiliates	5,226,546	5,071,521
Deferred income	0	0
Intangible lease liabilities, net	0	0
Interest rate swaps	0	0
Total liabilities	5,227,198	5,102,751
Stockholders’ Equity:
Common stock	1,453	1,452
Additional paid-in capital	3,679,578	3,676,000
Cumulative distributions in excess of earnings	(3,792,357)	(3,833,873)
Other comprehensive loss income	0	0
Piedmont stockholders’ equity	(111,326)	(156,421)
Noncontrolling interest	0	0
Total stockholders’ equity	(111,326)	(156,421)
Total liabilities and stockholders’ equity	5,115,872	4,946,330
Non-Guarantor Subsidiaries
Assets:
Land	571,005	571,005
Buildings and improvements, less accumulated depreciation	2,516,763	2,526,212
Intangible lease assets, less accumulated amortization	78,383	98,970
Construction in progress	8,160	34,669
Real estate assets held for sale, net		225,939
Total real estate assets	3,174,311	3,456,795
Investments in and amounts due from unconsolidated joint ventures	0	0
Cash and cash equivalents	10,074	3,168	$ 2,291	$ 3,117
Tenant and straight-line rent receivables, net	177,855	170,124
Advances to affiliates	0	0
Investment in subsidiary	177	181
Note receivable	144,500	95,790
Prepaid expenses, restricted cash, escrows, and other assets	25,358	20,121
Goodwill	0	0
Interest rate swaps	0
Deferred lease costs, net	260,957	282,145
Other assets held for sale, net		9,815
Total assets	3,793,232	4,038,139
Liabilities:
Debt, net	425,409	503,242
Accounts payable, accrued expenses, and accrued capital expenditures	91,731	118,712
Advances from affiliates	1,915,105	2,098,146
Deferred income	26,242	23,200
Intangible lease liabilities, net	41,064	48,005
Interest rate swaps	0	0
Total liabilities	2,499,551	2,791,305
Stockholders’ Equity:
Common stock	0	0
Additional paid-in capital	1,304	1,309
Cumulative distributions in excess of earnings	1,290,513	1,243,643
Other comprehensive loss income	0	0
Piedmont stockholders’ equity	1,291,817	1,244,952
Noncontrolling interest	1,864	1,882
Total stockholders’ equity	1,293,681	1,246,834
Total liabilities and stockholders’ equity	$ 3,793,232	$ 4,038,139

Guarantor and Non-Guarantor Financial Information (Condensed Consolidated Statements of Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Revenues:
Rental income	$ 113,350	$ 113,821	$ 361,048	$ 340,326
Tenant reimbursements	23,796	24,163	72,340	70,000
Property management fee revenue	441	501	1,341	1,478
Total revenues	137,587	138,485	434,729	411,804
Expenses:
Property operating costs	54,090	54,867	165,253	161,438
Depreciation	30,000	31,610	90,827	94,948
Amortization	18,123	18,640	57,852	53,848
Impairment loss on real estate assets	0	22,951	0	33,901
General and administrative	6,618	7,429	23,250	23,518
Operating expenses	108,831	135,497	337,182	367,653
Real estate operating income	28,756	2,988	97,547	44,151
Other income (expense):
Interest expense	(16,183)	(15,496)	(52,661)	(48,294)
Other income/(expense)	290	(720)	228	(467)
Net recoveries from casualty events	0	34	0	34
Equity in income of unconsolidated joint ventures	3,754	129	3,872	354
Other income (expense)	(12,139)	(16,053)	(48,561)	(48,373)
Income/(loss) from continuing operations	16,617	(13,065)	48,986	(4,222)
Discontinued operations:
Operating income	0	1	0	0
Income from discontinued operations	0	1	0	0
Gain/(loss) on sale of real estate assets, net	109,512	(57)	115,951	73,758
Net income/(loss)	126,129	(13,121)	164,937	69,536
Plus: Net income applicable to noncontrolling interest	4	14	10	7	$ 15
Net income/(loss) applicable to Piedmont	126,133	(13,107)	164,947	69,543	$ 99,732
Eliminations
Revenues:
Rental income	(426)	(464)	(1,370)	(1,983)
Tenant reimbursements	(142)	(237)	(373)	(405)
Property management fee revenue	(4,112)	(3,484)	(12,412)	(11,002)
Total revenues	(4,680)	(4,185)	(14,155)	(13,390)
Expenses:
Property operating costs	(4,680)	(4,240)	(14,155)	(13,514)
Depreciation	0	0	0	0
Amortization	0	0	0	0
Impairment loss on real estate assets		0		0
General and administrative	0	(8,857)	0	(28,416)
Operating expenses	(4,680)	(13,097)	(14,155)	(41,930)
Real estate operating income	0	8,912	0	28,540
Other income (expense):
Interest expense	3,966	3,252	11,256	8,219
Other income/(expense)	(3,966)	(3,252)	(11,256)	(8,219)
Net recoveries from casualty events		0		0
Equity in income of unconsolidated joint ventures	0	0	0	0
Other income (expense)	0	0	0	0
Income/(loss) from continuing operations	0	8,912	0	28,540
Discontinued operations:
Operating income	0	0	0	0
Income from discontinued operations	0	0	0	0
Gain/(loss) on sale of real estate assets, net	0	0	0	0
Net income/(loss)	0	8,912	0	28,540
Plus: Net income applicable to noncontrolling interest	0	0	0	0
Net income/(loss) applicable to Piedmont	0	8,912	0	28,540
Issuer
Revenues:
Rental income	10,232	12,862	32,749	42,990
Tenant reimbursements	2,376	3,430	8,341	10,455
Property management fee revenue	0	0	0	0
Total revenues	12,608	16,292	41,090	53,445
Expenses:
Property operating costs	5,372	7,820	17,027	24,583
Depreciation	3,199	3,617	9,943	12,993
Amortization	740	863	2,399	2,854
Impairment loss on real estate assets		0		8,259
General and administrative	1,539	7,187	4,798	22,802
Operating expenses	10,850	19,487	34,167	71,491
Real estate operating income	1,758	(3,195)	6,923	(18,046)
Other income (expense):
Interest expense	(13,795)	(11,799)	(43,049)	(36,159)
Other income/(expense)	2,404	2,608	6,873	7,008
Net recoveries from casualty events		0		0
Equity in income of unconsolidated joint ventures	3,754	129	3,872	354
Other income (expense)	(7,637)	(9,062)	(32,304)	(28,797)
Income/(loss) from continuing operations	(5,879)	(12,257)	(25,381)	(46,843)
Discontinued operations:
Operating income	0	0	0	0
Income from discontinued operations	0	0	0	0
Gain/(loss) on sale of real estate assets, net	(4)	134	6,430	30,096
Net income/(loss)	(5,883)	(12,123)	(18,951)	(16,747)
Plus: Net income applicable to noncontrolling interest	0	0	0	0
Net income/(loss) applicable to Piedmont	(5,883)	(12,123)	(18,951)	(16,747)
Guarantor
Revenues:
Rental income	0	0	0	0
Tenant reimbursements	0	0	0	0
Property management fee revenue	0	0	0	0
Total revenues	0	0	0	0
Expenses:
Property operating costs	0	0	0	0
Depreciation	0	0	0	0
Amortization	0	0	0	0
Impairment loss on real estate assets		0		0
General and administrative	77	83	261	251
Operating expenses	77	83	261	251
Real estate operating income	(77)	(83)	(261)	(251)
Other income (expense):
Interest expense	0	0	0	0
Other income/(expense)	0	0	0	282
Net recoveries from casualty events		0		0
Equity in income of unconsolidated joint ventures	0	0	0	0
Other income (expense)	0	0	0	282
Income/(loss) from continuing operations	(77)	(83)	(261)	31
Discontinued operations:
Operating income	0	0	0	0
Income from discontinued operations	0	0	0	0
Gain/(loss) on sale of real estate assets, net	0	0	0	0
Net income/(loss)	(77)	(83)	(261)	31
Plus: Net income applicable to noncontrolling interest	0	0	0	0
Net income/(loss) applicable to Piedmont	(77)	(83)	(261)	31
Non-Guarantor Subsidiaries
Revenues:
Rental income	103,544	101,423	329,669	299,319
Tenant reimbursements	21,562	20,970	64,372	59,950
Property management fee revenue	4,553	3,985	13,753	12,480
Total revenues	129,659	126,378	407,794	371,749
Expenses:
Property operating costs	53,398	51,287	162,381	150,369
Depreciation	26,801	27,993	80,884	81,955
Amortization	17,383	17,777	55,453	50,994
Impairment loss on real estate assets		22,951		25,642
General and administrative	5,002	9,016	18,191	28,881
Operating expenses	102,584	129,024	316,909	337,841
Real estate operating income	27,075	(2,646)	90,885	33,908
Other income (expense):
Interest expense	(6,354)	(6,949)	(20,868)	(20,354)
Other income/(expense)	1,852	(76)	4,611	462
Net recoveries from casualty events		34		34
Equity in income of unconsolidated joint ventures	0	0	0	0
Other income (expense)	(4,502)	(6,991)	(16,257)	(19,858)
Income/(loss) from continuing operations	22,573	(9,637)	74,628	14,050
Discontinued operations:
Operating income	0	1	0	0
Income from discontinued operations	0	1	0	0
Gain/(loss) on sale of real estate assets, net	109,516	(191)	109,521	43,662
Net income/(loss)	132,089	(9,827)	184,149	57,712
Plus: Net income applicable to noncontrolling interest	4	14	10	7
Net income/(loss) applicable to Piedmont	$ 132,093	$ (9,813)	$ 184,159	$ 57,719

Guarantor and Non-Guarantor Financial Information (Condensed Consolidated Statements of Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	$ 176,332	$ 172,036
Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	(65,407)	(321,139)
Intercompany note receivable	0	0
Net sales proceeds from wholly-owned properties	375,199	304,902
Net sales proceeds from unconsolidated joint ventures	12,334	0
Investments in unconsolidated joint ventures	(1,162)	0
Deferred lease costs paid	(19,419)	(15,345)
Net cash provided by/(used in) investing activities	301,545	(31,582)
Cash Flows from Financing Activities:
Debt issuance costs paid	(101)	(212)
Proceeds from debt	147,000	552,000
Repayments of debt	(466,046)	(589,532)
Intercompany note payable	0	0
Costs of issuance of common stock	(97)	(239)
Value of shares withheld to pay tax obligations related to employee stock compensation	(3,385)	(2,328)
Repurchases of common stock as part of announced plan	(3,895)	(7,943)
(Distributions to)/repayments from affiliates	0	0
Dividends paid and discount on dividend reinvestments	(122,237)	(91,609)
Net cash used in financing activities	(448,761)	(139,863)
Net increase in cash and cash equivalents	29,116	591
Cash and cash equivalents, beginning of period	6,992	5,441
Cash and cash equivalents, end of period	36,108	6,032
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	0	28,540
Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	0	0
Intercompany note receivable	48,710	71,460
Net sales proceeds from wholly-owned properties	0	0
Net sales proceeds from unconsolidated joint ventures	0
Investments in unconsolidated joint ventures	0
Deferred lease costs paid	0	0
Net cash provided by/(used in) investing activities	48,710	71,460
Cash Flows from Financing Activities:
Debt issuance costs paid	0	0
Proceeds from debt	0	0
Repayments of debt	0	0
Intercompany note payable	(48,710)	(71,460)
Costs of issuance of common stock	0	0
Value of shares withheld to pay tax obligations related to employee stock compensation	0	0
Repurchases of common stock as part of announced plan	0	0
(Distributions to)/repayments from affiliates	0	(28,540)
Dividends paid and discount on dividend reinvestments	0	0
Net cash used in financing activities	(48,710)	(100,000)
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Issuer
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	(15,467)	(18,977)
Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	(793)	(24,255)
Intercompany note receivable	0	440
Net sales proceeds from wholly-owned properties	23,028	187,192
Net sales proceeds from unconsolidated joint ventures	12,334
Investments in unconsolidated joint ventures	(1,162)
Deferred lease costs paid	(858)	(2,021)
Net cash provided by/(used in) investing activities	32,549	161,356
Cash Flows from Financing Activities:
Debt issuance costs paid	(102)	(212)
Proceeds from debt	147,000	552,000
Repayments of debt	(325,000)	(421,000)
Intercompany note payable	(14,289)	(9,600)
Costs of issuance of common stock	0	0
Value of shares withheld to pay tax obligations related to employee stock compensation	0	0
Repurchases of common stock as part of announced plan	0	0
(Distributions to)/repayments from affiliates	197,519	(262,150)
Dividends paid and discount on dividend reinvestments	0	0
Net cash used in financing activities	5,128	(140,962)
Net increase in cash and cash equivalents	22,210	1,417
Cash and cash equivalents, beginning of period	3,674	2,174
Cash and cash equivalents, end of period	25,884	3,591
Guarantor
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	4,335	4,121
Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	0	0
Intercompany note receivable	0	0
Net sales proceeds from wholly-owned properties	0	0
Net sales proceeds from unconsolidated joint ventures	0
Investments in unconsolidated joint ventures	0
Deferred lease costs paid	0	0
Net cash provided by/(used in) investing activities	0	0
Cash Flows from Financing Activities:
Debt issuance costs paid	0	0
Proceeds from debt	0	0
Repayments of debt	0	0
Intercompany note payable	0	0
Costs of issuance of common stock	(97)	(239)
Value of shares withheld to pay tax obligations related to employee stock compensation	(3,385)	(2,328)
Repurchases of common stock as part of announced plan	(3,895)	(7,943)
(Distributions to)/repayments from affiliates	125,271	97,990
Dividends paid and discount on dividend reinvestments	(122,229)	(91,601)
Net cash used in financing activities	(4,335)	(4,121)
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	150	150
Cash and cash equivalents, end of period	150	150
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	187,464	158,352
Cash Flows from Investing Activities:
Investment in real estate assets and real estate related intangibles, net of accruals	(64,614)	(296,884)
Intercompany note receivable	(48,710)	(71,900)
Net sales proceeds from wholly-owned properties	352,171	117,710
Net sales proceeds from unconsolidated joint ventures	0
Investments in unconsolidated joint ventures	0
Deferred lease costs paid	(18,561)	(13,324)
Net cash provided by/(used in) investing activities	220,286	(264,398)
Cash Flows from Financing Activities:
Debt issuance costs paid	1	0
Proceeds from debt	0	0
Repayments of debt	(141,046)	(168,532)
Intercompany note payable	62,999	81,060
Costs of issuance of common stock	0	0
Value of shares withheld to pay tax obligations related to employee stock compensation	0	0
Repurchases of common stock as part of announced plan	0	0
(Distributions to)/repayments from affiliates	(322,790)	192,700
Dividends paid and discount on dividend reinvestments	(8)	(8)
Net cash used in financing activities	(400,844)	105,220
Net increase in cash and cash equivalents	6,906	(826)
Cash and cash equivalents, beginning of period	3,168	3,117
Cash and cash equivalents, end of period	$ 10,074	$ 2,291

Subsequent Events (Details)	Oct. 31, 2017 $ / shares
Subsequent Event
Subsequent Event [Line Items]
Dividends declared (in dollars per share)	$ 0.21

Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Statement of Stockholders' Equity [Abstract]
Dividends to common stockholders per share (in USD per share)	$ 0.63	$ 0.84

Stock Based Compensation (Outstanding Employee Stock Awards) (Details) - $ / shares	May 18, 2017	May 24, 2016	May 01, 2015	Jan. 03, 2014	Sep. 30, 2017	Dec. 31, 2016
Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant Date Fair Value (in dollars per share)					$ 21.39	$ 19.44
Unvested Shares (in shares)					807,526	944,223
Deferred Stock Awards \| Deferred Stock Award, Granted January 3, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)				86,769
Grant Date Fair Value (in dollars per share)				$ 16.56
Unvested Shares (in shares)					35,094
Deferred Stock Awards \| Deferred Stock Award, Granted January 3, 2014 \| Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				20.00%
Deferred Stock Awards \| Deferred Stock Award, Granted January 3, 2014 \| Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				20.00%
Deferred Stock Awards \| Deferred Stock Award, Granted January 3, 2014 \| Share-based Compensation Award, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				20.00%
Deferred Stock Awards \| Deferred Stock Award, Granted January 3, 2014 \| Share-based Compensation Award, Tranche Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				20.00%
Deferred Stock Awards \| Deferred Stock Award, Granted January 3, 2014 \| Share-based Compensation Award, Tranche Five
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				20.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 1, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)			216,837
Grant Date Fair Value (in dollars per share)			$ 17.59
Unvested Shares (in shares)					67,114
Deferred Stock Awards \| Deferred Stock Award, Granted May 1, 2015 \| Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 1, 2015 \| Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 1, 2015 \| Share-based Compensation Award, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 1, 2015 \| Share-based Compensation Award, Tranche Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 24, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)		233,011
Grant Date Fair Value (in dollars per share)		$ 19.91
Unvested Shares (in shares)					133,092
Deferred Stock Awards \| Deferred Stock Award, Granted May 24, 2016 \| Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 24, 2016 \| Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 24, 2016 \| Share-based Compensation Award, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 24, 2016 \| Share-based Compensation Award, Tranche Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)	246,740
Grant Date Fair Value (in dollars per share)	$ 21.38
Unvested Shares (in shares)					200,899
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017 \| Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)	26,187
Grant Date Fair Value (in dollars per share)	$ 21.38
Unvested Shares (in shares)					26,187
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017 \| Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017 \| Share-based Compensation Award, Tranche One \| Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	100.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017 \| Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017 \| Share-based Compensation Award, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Deferred Stock Awards \| Deferred Stock Award, Granted May 18, 2017 \| Share-based Compensation Award, Tranche Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Performance Share Awards \| Performance Share Program Award, Granted May 1, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)			0
Grant Date Fair Value (in dollars per share)			$ 18.42
Unvested Shares (in shares)					143,846
Performance Share Awards \| Performance Share Program Award, Granted May 24, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)		0
Grant Date Fair Value (in dollars per share)		$ 23.02
Unvested Shares (in shares)					103,790
Performance Share Awards \| Performance Share Program Award, Granted May 18, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Shares Granted (in shares)	0
Grant Date Fair Value (in dollars per share)	$ 30.45
Unvested Shares (in shares)					97,504