Accounting Policies [Abstract] Summary of Significant Accounting Policies Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Office properties [Member] Office properties [Member] Legal Entity [Axis] Entity [Domain] Unconsolidated Joint Venture [Member] Unconsolidated Joint Venture [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] Number of wholly-owned subsidiaries Number Of Wholly Owned Management Subsidiaries Number Of Wholly Owned Management Subsidiaries Percentage ownership by sole general partner Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Percentage ownership by sole limited partner Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest Number of real estate properties Number of Real Estate Properties Number of redevelopment assets Number of Real Estate Properties To Be Redeveloped The number of real estate properties owned as of the balance sheet date which are not in service because they are subject to redevelopment. Number of office properties under development Number of Real Estate Properties Under Development Number of Real Estate Properties Under Development Square footage of real estate property Area of Real Estate Property Percentage leased Percentage of Leased Real Estate Properties Percentage of Leased Real Estate Properties Percentage of annualized lease revenue Operating Leases, Income Statement, Percentage of Annualized Lease Revenue Operating Leases, Income Statement, Percentage of Annualized Lease Revenue Number of operating segments Number of Operating Segments Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Variable Interest Entities by Classification of Entity [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Eye Street 1201 N.W. Associates LLC [Member] Eye Street 1201 NW Associates LLC [Member] Eye Street 1201 NW Associates LLC [Member] Eye Street 1225 N.W. Associates LLC [Member] Eye Street 1225 NW Associates LLC [Member] Eye Street 1225 NW Associates LLC [Member] Piedmont 500 W. Monroe Fee LLC [Member] Piedmont 500 W. Monroe Fee LLC [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Piedmont’s % Ownership of Entity Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Net Carrying Amount Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net Variable interest entity, cash flow percent entitled to entity Variable Interest Entity Cash Flow Percent Entitled To Entity Variable Interest Entity Cash Flow Percent Entitled To Entity Earnings Per Share [Abstract] Weighted-average common shares – basic Weighted Average Number of Shares Outstanding, Basic Deferred and performance stock awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted-average common shares outstanding – diluted Weighted Average Number of Shares Outstanding, Diluted Common stock, shares outstanding Common Stock, Shares, Outstanding Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Statement of Comprehensive Income [Abstract] Net income applicable to Piedmont Net Income (Loss) Attributable to Parent Other comprehensive income/(loss): Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Effective portion of gain/(loss) on derivative instruments that are designated and qualify as cash flow hedges (See Note 5) Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Plus: Reclassification of previously recorded loss included in net income (See Note 5) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Gain/(loss) on investment in available for sale securities Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Other comprehensive income/(loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Comprehensive income applicable to Piedmont Comprehensive Income (Loss), Net of Tax, Attributable to Parent Income Statement [Abstract] Revenues: Revenues [Abstract] Rental income Operating Leases, Income Statement, Lease Revenue Tenant reimbursements Tenant Reimbursements Property management fee revenue Management Fees Revenue Total revenues Revenues Expenses: Operating Expenses [Abstract] Property operating costs Direct Costs of Leased and Rented Property or Equipment Depreciation Depreciation, Continuing Operations The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives, from continuing operations. Amortization Adjustment for Amortization, Continuing Operations The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives, from continuing operations. Impairment loss on real estate assets Asset Impairment Charges General and administrative General and Administrative Expense Operating expenses Operating Expenses Real estate operating income Operating Income (Loss) Other income (expense): Nonoperating Income (Expense) [Abstract] Interest expense Interest Expense Other income/(expense) Other Nonoperating Income (Expense) Equity in income of unconsolidated joint ventures Income (Loss) from Equity Method Investments Other income (expense) Nonoperating Income (Expense) Income from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Discontinued operations: Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent [Abstract] Operating loss Disposal Group, Including Discontinued Operation, Operating Income (Loss) Loss from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Gain on sale of real estate assets Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Less: Net income applicable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income applicable to Piedmont Per share information – basic and diluted: Earnings Per Share, Basic and Diluted [Abstract] Income from continuing operations and gain/(loss) on sale of real estate assets (in dollars per share) Income (Loss) from Continuing Operations, Per Basic and Diluted Share Net income applicable to common stockholders (in dollars per share) Earnings Per Share, Basic and Diluted Weighted-average common shares outstanding – basic Real Estate [Abstract] Real Estate [Table] Real Estate [Table] Real Estate [Table] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group, Held-for-sale, Not Discontinued Operations [Member] Disposal Group, Held-for-sale, Not Discontinued Operations [Member] Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] 150 West Jefferson building [Member] WEST JEFFERSON 150 [Member] WEST JEFFERSON 150 [Member] 9221 Corporate Drive [Member] CORPORATE BOULEVARD 9221 [Member] CORPORATE BOULEVARD 9221 [Member] Real Estate [Line Items] Real Estate [Line Items] [Line Items] for Real Estate [Table] Impairment loss on real estate assets held for sale Impairment of Long-Lived Assets to be Disposed of Impairment loss for property that did not meet the requirements for held for sale classification Impairment of Real Estate Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] 3900 Dallas Parkway [Member] DALLAS PARKWAY 3900 [Member] DALLAS PARKWAY 3900 [Member] 5601 Headquarters Drive [Member] HEADQUARTERS DRIVE 5601 [Member] HEADQUARTERS DRIVE 5601 [Member] River Corporate Center [Member] RIVER CORPORATE CENTER [Member] RIVER CORPORATE CENTER [Member] Copper Ridge Center [Member] COPPER RIDGE CENTER [Member] COPPER RIDGE CENTER [Member] 1055 E. Colorado [Member] EAST COLORADO BOULEVARD 1055 [Member] EAST COLORADO BOULEVARD 1055 [Member] Fairway Center II [Member] FAIRWAY CENTER II [Member] FAIRWAY CENTER II [Member] 1901 Main Street [Member] MAIN STREET 1901 [Member] MAIN STREET 1901 [Member] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Notes receivable [Member] Notes Receivable [Member] Schedule of Receivables with Imputed Interest, Name of Receivable with Imputed Interest [Axis] Schedule of Receivables with Imputed Interest, Name of Receivable with Imputed Interest [Axis] Name of Receivable with Imputed Interest [Domain] Name of Receivable with Imputed Interest [Domain] Secured Promissory Note [Member] Secured Promissory Note [Member] Secured Promissory Note [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Gain/(Loss) on Sale Gains (Losses) on Sales of Investment Real Estate Net Sales Proceeds Proceeds from Divestiture of Businesses, Net of Cash Divested Note receivable Financing Receivable, Net Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] CNL Tower I and II [Member] CNL Tower I and II [Member] CNL Tower I and II [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Percentage of controlling interest acquired Business Acquisition, Percentage of Voting Interests Acquired Number of trophy office buildings acquired Business Acquisition, Number of Buildings Business Acquisition, Number of Buildings Amount of acquisition Business Combination, Consideration Transferred Gross sales price Disposal Group, Including Discontinued Operation, Consideration Sales price per square foot Disposal Group, Including Discontinued Operation, Consideration per Square Foot Disposal Group, Including Discontinued Operation, Consideration per Square Foot Schedule of Weighted Average Number of Shares Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Equity Award [Domain] Stock Awards [Member] Stock Awards [Member] Stock Awards [Member] Performance Share Awards [Member] Performance Shares [Member] Deferred Stock Awards [Member] Deferred Stock Award [Member] Deferred Stock Award [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Unvested Stock Awards, Beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Deferred Stock Awards Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Increase in Estimated Potential Future Performance Share Awards (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Increase in Estimated Potential Future Awards Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Increase in Estimated Potential Future Awards Performance Stock Awards and Deferred Stock Awards Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Deferred Stock Awards Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Unvested Stock Awards, End of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Unvested Stock Awards, Weighted-Average Grant Date Fair Value, Beginning of period (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Deferred Stock Awards Granted, Weighted-Average Grant Date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Increase in Estimated Potential Future Performance Share Awards, Weighted-Average Grant Date Fair Value (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Increase in Estimated Potential Future Awards, Weighted Average Grant Date Fair Value Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Increase in Estimated Potential Future Awards, Weighted Average Grant Date Fair Value Performance Stock Awards and Deferred Stock Awards Vested, Weighted-Average Grant Date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Deferred Stock Awards Forfeited, Weighted-Average Grant Date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Unvested Stock Awards, Weighted-Average Grant Date Fair Value, End of period (in dollars per share) Property Dispositions, Assets Held for Sale, and Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Debt Disclosure [Abstract] Schedule of Debt Instruments [Table] Schedule of Debt Instruments [Table] Schedule of Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Secured Debt [Member] Unsecured Debt [Member] Debt Instrument [Axis] Debt Instrument, Name [Domain] $125 Million Fixed Rate Loan [Member] Fixed-Rate 125Million Loan [Member] Fixed-Rate 125Million Loan [Member] $42.5 Million Fixed Rate Loan [Member] Fixed-Rate 42.5Million Loan [Member] Fixed-Rate 42.5Million Loan [Member] $140 Million WDC Fixed Rate Loans [Member] WDC Mortgage Notes [Member] WDC Mortgage Notes [Member] $35 Million Fixed-Rate Loan [Member] Mortgage Loan Maturing September 1, 2021 [Member] Mortgage Loan Maturing September 1, 2021 [Member] $160 Million Fixed Rate Loan [Member] Fixed Rate 160 Million Loan [Member] Fixed Rate 160 Million Loan [Member] $170 Million Unsecured 2015 Term Loan [Member] Unsecured 170 Million 2015 Term Loan [Member] Unsecured 170 Million 2015 Term Loan [Member] $300 million Unsecured 2013 Term Loan [Member] Unsecured 300 million 2013 Term Loan Maturing 2019 [Member] Unsecured 300 million 2013 Term Loan Maturing 2019 [Member] $500 Million Unsecured 2015 Line of Credit [Member] Unsecured 500 Million 2015 Line of Credit [Member] Unsecured 500 Million 2015 Line of Credit [Member] $300 Million Unsecured 2011 Term Loan [Member] $300 Million 2011 Unsecured Term Loan Maturing 2020 [Member] $300 Million 2011 Unsecured Term Loan Maturing 2020 [Member] $350 Million Unsecured Senior Notes [Member] Senior 350 Million Notes [Member] Senior 350 Million Notes [Member] $400 Million Unsecured Senior Notes [Member] Senior 2014 Notes [Member] Senior 2014 Notes [Member] $300 Million Unsecured 2011 Term Loan Maturing 2016 [Member] $300 Million 2011 Unsecured Term Loan Maturing 2016 [Member] $300 Million 2011 Unsecured Term Loan Maturing 2016 [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Line of Credit [Member] Line of Credit [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest Rate Swap [Member] Interest Rate Swap [Member] Debt Instrument [Line Items] Face amount of debt instrument Debt Instrument, Face Amount Rate Debt Instrument, Interest Rate, Stated Percentage Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Weighted Average Rate Debt, Weighted Average Interest Rate Amount Outstanding Notes and Loans Payable Net premium, discounts, and unamortized debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Effective interest rate Debt Instrument, Interest Rate, Effective Percentage LIBOR rate in effect LIBOR Interest Rate In Effect LIBOR Interest Rate In Effect Maximum extension period Line Of Credit Facility, Maximum Maturity Extension Period Line Of Credit Facility, Maximum Maturity Extension Period Number of extension periods Line Of Credit Facility, Number of Maturity Extension Periods Line Of Credit Facility, Number of Maturity Extension Periods Extension period Line Of Credit Facility, Maturity Extension Period Line Of Credit Facility, Maturity Extension Period Effective interest rate Debt Instrument, Interest Rate, Effective Percentage Including Swap Settlement Effective interest rate for the funds borrowed under the debt agreement considering original issue of discount or premium as well as the impact of settled interest rate swaps Guarantor and Non-Guarantor Financial Information Condensed Financial Statements [Text Block] Derivative [Table] Derivative [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Interest Rate Swap 1 through 4 [Member] Interest Rate Swap 1 through 4 [Member] Interest Rate Swap 1 through 4 [Member] Interest Rate Swap 5 through 8 [Member] Interest Rate Swap 5 through 8 [Member] Interest Rate Swap 5 through 8 [Member] Interest Rate Swap 9 through 10 [Member] Interest Rate Swap 9 through 10 [Member] Interest Rate Swap 9 through 10 [Member] Forward Starting Interest Rate Swap 1 through 3 [Member] Forward Starting Interest Rate Swap 1 through 3 [Member] Forward Starting Interest Rate Swap 1 through 3 [Member] Credit Risk Contract [Member] Credit Risk Contract [Member] Income Statement Location [Axis] Income Statement and Other Comprehensive Income (Loss) Location [Domain] Income Statement Location [Domain] Interest Expense [Member] Derivative [Line Items] Derivative [Line Items] Maximum period of extension term Maximum Length of Time Hedged in Cash Flow Hedge Number of Swap Agreements Number of Interest Rate Derivatives Held Total notional value Derivative, Notional Amount Interest Rate Cash Flow Hedge Derivative at Fair Value, Net [Abstract] Interest Rate Cash Flow Hedge Derivative at Fair Value, Net [Abstract] Gross derivative assets Interest Rate Cash Flow Hedge Asset at Fair Value Interest rate swaps Interest Rate Cash Flow Hedge Liability at Fair Value Net derivative liability Interest Rate Cash Flow Hedge Derivative at Fair Value, Net Amount of gain/(loss) recognized in OCI on derivative Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss) Amount of previously recorded loss reclassified from accumulated OCI into interest expense Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net Loss to be reclassified from accumulated other comprehensive loss to interest expense over next twelve months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Loss related to hedge ineffectiveness and terminations of cash flow hedges Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness Assets needed for immediate settlement, aggregate fair value Assets Needed for Immediate Settlement, Aggregate Fair Value Schedule of Condensed Financial Statements [Table] Condensed Financial Statements [Table] Legal Entity [Axis] Entity [Domain] Issuer [Member] Subsidiary Issuer [Member] Guarantor [Member] Guarantor [Member] The registrant that guarantees the debt issued by another entity it controls, either directly or indirectly. The usual condition for control is ownership of a majority (over 50%) of the outstanding voting stock. The power to control may also exist with a lesser percentage of ownership, for example, by contract, lease, agreement with other stockholders or by court decree. Non-Guarantor Subsidiaries [Member] Non-Guarantor Subsidiaries [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Eliminations [Member] Consolidation, Eliminations [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Other income/(expense) Discontinued operations: Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Net income applicable to noncontrolling interest Schedule of Debt Schedule of Debt [Table Text Block] Assets: Assets [Abstract] Land Land Buildings and improvements, less accumulated depreciation Investment Building and Building Improvements, Net Investment Building and Building Improvements, Net Intangible lease assets, less accumulated amortization Finite-Lived Intangible Assets, Net Construction in progress Construction in Progress, Gross Real estate assets held for sale, net Real Estate Held-for-sale Total real estate assets Real Estate Investment Property, Net Investments in and amounts due from unconsolidated joint ventures Unconsolidated Equity Method Investments and Due from Joint Ventures Unconsolidated Equity Method Investments and Due from Joint Ventures Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Tenant and straight-line rent receivables, net Tenant Receivables Including Straight Line Rental Revenue Receivables Tenant Receivables Including Straight Line Rental Revenue Receivables Advances to affiliates Due from Affiliates Investment in subsidiary Investment In Subsidiary Amount of Investment in an affiliate by means of direct or indirect ownership Prepaid expenses, restricted cash, escrows, and other assets Prepaid Expense and Restricted Cash and Cash Equivalents and Other Assets Prepaid Expense and Restricted Cash and Cash Equivalents and Other Assets Goodwill Goodwill Deferred lease costs, net Deferred Costs, Leasing, Net Other assets held for sale, net Disposal Group, Including Discontinued Operation, Other Assets Total assets Assets Liabilities: Liabilities [Abstract] Debt, net Long-term Debt Accounts payable, accrued expenses, and accrued capital expenditures Accounts Payable and Accrued Liabilities Advances from affiliates Due to Affiliate Deferred income Deferred Revenue Intangible lease liabilities, net Off-market Lease, Unfavorable Total liabilities Liabilities Stockholders’ Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Cumulative distributions in excess of earnings Accumulated Distributions in Excess of Net Income Other comprehensive income/(loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Piedmont stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total stockholders’ equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and stockholders’ equity Liabilities and Equity Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Building and improvements Member] Building and Building Improvements [Member] Unsecured Debt [Member] Secured Debt [Member] Statement [Line Items] Statement [Line Items] Assets: Buildings and improvements, accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Intangible lease assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Tenant receivables, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable Deferred lease costs, accumulated amortization Deferred Costs, Leasing, Accumulated Amortization Discount, (premiums) and unamortized debt issuance costs Intangible lease liabilities, accumulated amortization Intangible Lease Liabilities Accumulated Amortization Intangible Lease Liabilities Accumulated Amortization Stockholders’ Equity: Stockholders' Equity Attributable to Parent [Abstract] Shares-in-trust, shares authorized Shares In Trust Authorized Shares In Trust Authorized Shares-in-trust, shares outstanding Shares In Trust, Outstanding Shares In Trust, Outstanding Preferred stock, par value (in dollars per share) Preferred Stock, No Par Value Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Accounting Pronouncements Adopted and Other Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Statement of Stockholders' Equity [Abstract] Statement, Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Common Stock [Member] Additional Paid-In Capital [Member] Additional Paid-in Capital [Member] Cumulative Distributions in Excess of Earnings [Member] Retained Earnings [Member] Other Comprehensive Income/ (Loss) [Member] AOCI Attributable to Parent [Member] Non-controlling Interest [Member] Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Balance (in shares) Share repurchases as part of an announced plan Stock Repurchased and Retired During Period, Value Share repurchases as part of an announced plan, shares Stock Repurchased and Retired During Period, Shares Offering costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Redemption of noncontrolling interest in consolidated variable interest entity Redemption of Noncontrolling Interest in Consolidated Variable Interest Entity Redemption of noncontrolling interest in consolidated variable interest entity Reallocation of noncontrolling interest of subsidiary Noncontrolling Interest, Reallocation of Noncontrolling Interest of Subsidiary Reallocation of noncontrolling interest of subsidiary Dividends to common stockholders ($0.84 (YTD 2015) and $0.42 (YTD 2016) per share), dividends to stockholders of subsidiary, and dividends reinvested Dividends, Minority Interest (Decrease) From Distributions to Noncontrolling Interest Holders and Stock Issued During Period Value Dividend Reinvestment Plan Sum of a) Equity impact of aggregate cash, stock, and paid-in-kind dividends declared for all securities (common shares, preferred shares, etc.) during the period, b) Decrease in noncontrolling interest balance from payment of dividends or other distributions by the non-wholly owned subsidiary or partially owned entity, included in the consolidation of the parent entity, to the noncontrolling interest holders, and c) Value of stock issued during the period from a dividend reinvestment plan (DRP). A dividend reinvestment plan allows the holder of the stock to reinvest dividends paid to them by the entity on new issues of stock or stock purchased and reissued by the entity. Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Shares issued and amortized under the 2007 Omnibus Incentive Plan, net of tax (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Net income applicable to noncontrolling interest Net income applicable to Piedmont Other comprehensive loss Balance Balance (in shares) Land [Member] Land [Member] Construction in progress [Member] Construction in Progress [Member] Real estate assets held for sale, net: Disposal Group, Including Discontinued Operation, Property, Plant and Equipment Accumulated depreciation and amortization Disposal Group, Including Discontinued Operation, Accumulated Depreciation, Property Plant and Equipment Disposal Group, Including Discontinued Operation, Accumulated Depreciation, Property Plant and Equipment Total real estate assets held for sale, net Real Estate Held-for-sale, Net Net carrying amount as of the balance sheet date of investments in land, buildings, finite-lived intangibles, and construction in progress classified as held for sale. Straight-line rent receivables Disposal Group, Including Discontinued Operation, Straight-line Rent Disposal Group, Including Discontinued Operation, Straight-line Rent Prepaid expenses and other assets Disposal Group, Including Discontinued Operation, Prepaid and Other Assets Deferred lease costs, less accumulated amortization of $1,429 and $1,162 as of June 30, 2016 and December 31, 2015, respectively Disposal Group, Including Discontinued Operation, Deferred Lease Costs, Net Disposal Group, Including Discontinued Operation, Deferred Lease Costs, Net Accumulated amortization on deferred lease costs Disposal Group, Including Discontinued Operation, Deferred Lease Costs, Accumulated Amortization Disposal Group, Including Discontinued Operation, Deferred Lease Costs, Accumulated Amortization Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities Cash Flows from Investing Activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Investment in real estate assets and real estate related intangibles, net of accruals Payments to Acquire and Develop Real Estate Intercompany note receivable Payments for (Proceeds from) Intercompany Notes Receivable, Investing Activities Payments for (Proceeds from) Intercompany Notes Receivable, Investing Activities Redemption of noncontrolling interest in unconsolidated variable interest entity Payments for Repurchase of Redeemable Noncontrolling Interest Net sales proceeds from wholly-owned properties Deferred lease costs paid Increase (Decrease) in Lease Acquisition Costs Net cash provided by/(used in) investing activities Net Cash Provided by (Used in) Investing Activities Cash Flows from Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Debt issuance costs paid Payments of Financing Costs Proceeds from debt Proceeds from Notes Payable Repayments of debt Repayments of Notes Payable Intercompany note payable Payments for (Proceeds from) Intercompany Notes Payable Payments for (Proceeds from) Intercompany Notes Payable Costs of issuance of common stock Payments of Stock Issuance Costs Shares withheld to pay tax obligations related to employee stock compensation Payments Related to Tax Withholding for Share-based Compensation Repurchases of common stock as part of announced plan Payments for Repurchase of Common Stock (Distributions to)/repayments from affiliates Payments for (Proceeds from) Intercompany Distributions Payments for (Proceeds from) Intercompany Distributions Dividends paid and discount on dividend reinvestments Payments of Dividends Common Stock, Distributions To Noncontrolling Interest and Discount on Dividend Reinvestment Sum of a) The cash outflow from the distribution of an entity's earnings in the form of dividends to common stockholders, and b) Distributions to noncontrolling interest, and c)Discount on dividend reinvestments. Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net increase/(decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument [Line Items] Amount repaid Repayments of Debt Amount of line of credit Line of Credit Facility, Maximum Borrowing Capacity Number of properties sold Number of Real Estate Properties Sold Number of Real Estate Properties Sold Interest payments on debt facilities Interest Paid Capitalized interest Interest Costs Capitalized Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Category of Item Purchased [Axis] Category of Item Purchased [Axis] Long-term Purchase Commitment, Category of Item Purchased [Domain] Long-term Purchase Commitment, Category of Item Purchased [Domain] Non-Incremental Capital Expenditures [Member] NonIncremental Capital Expenditures [Member] Non-Incremental Capital Expenditures are defined as capital expenditures of a recurring nature related to tenant improvements and leasing commissions that do not incrementally enhance the underlying assets' income generating capacity. We exclude first generation tenant improvements and leasing commissions from this measure, in addition to other capital expenditures that qualify as Incremental Capital Expenditures, as defined above. Incremental Capital Expenditures [Member] Incremental Capital Expenditures [Member] Incremental Capital Expenditures are defined as capital expenditures of a non-recurring nature that incrementally enhance the underlying assets' income generating capacity. Tenant improvements, leasing commissions, building capital and deferred lease incentives ("Leasing Costs") incurred to lease space that was vacant at acquisition, Leasing Costs for spaces vacant for greater than one year, Leasing Costs for spaces at newly acquired properties for which in-place leases expire shortly after acquisition, improvements associated with the expansion of a building and renovations that change the underlying classification of a building are included in this measure. Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Collectibility of Tenant Reimbursements [Member] Collectibility of Tenant Reimbursements [Member] Collectibility of Tenant Reimbursements [Member] Tenant Audits and Disputes [Member] Tenant Audits and Disputes [Member] Tenant Audits and Disputes [Member] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Pending Litigation [Member] Pending Litigation [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Loss Contingencies [Line Items] Number of tenant and building improvement categories Number of Tenant and Building Improvement Categories Number of Tenant and Building Improvement Categories Period for commitments for funding non-incremental capital expenditures Long-term Purchase Commitment, Period Potential obligations for tenant improvements Commitment to Provide Funding to Tenants for Capital Improvements Commitment to Provide Funding to Tenants for Capital Improvements Reductions in reimbursement revenues Loss Contingency, Loss in Period Number of tenants Number of Tenants Number of Tenants Amount of potential loss Loss Contingency, Estimate of Possible Loss Dividends to common stockholders per share Common Stock, Dividends, Per Share, Cash Paid Accounting Changes and Error Corrections [Abstract] New Accounting Pronouncement, Early Adoption [Table] New Accounting Pronouncement, Early Adoption [Table] New Accounting Pronouncement, Early Adoption [Axis] New Accounting Pronouncement, Early Adoption [Axis] New Accounting Principles, Early Adoption [Domain] New Accounting Principles, Early Adoption [Domain] New Accounting Pronouncement, Early Adoption, Effect [Member] New Accounting Pronouncement, Early Adoption, Effect [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-09 [Member] Accounting Standards Update 2016-09 [Member] Accounting Standards Update 2016-09 [Member] New Accounting Pronouncement, Early Adoption [Line Items] New Accounting Pronouncement, Early Adoption [Line Items] Reclassification of share-based payment transactions cash outflows from operating activities to cash outflows from financing activities Debt Debt Disclosure [Text Block] Award Type [Axis] Weighted-Average Grant Date Fair Value of Shares Granted During the Period (per share) Total Grant Date Fair Value of Shares Vested During the Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Share-based Liability Awards Paid During the Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share-based Liabilities Paid During Period The liabilities paid during the accounting period for equity-based compensation. Schedule of Nonvested Share Activity Schedule of Nonvested Share Activity [Table Text Block] Schedule of Outstanding Employee Stock Awards Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Discontinued Operations [Member] Discontinued Operations [Member] Tenant reimbursements Disposal Group, Including Discontinued Operation, Tenant Reimbursement Disposal Group, Including Discontinued Operation, Tenant Reimbursement Revenue Disposal Group, Including Discontinued Operation, Revenue Expenses: Expenses [Abstract] Expenses [Abstract] Property operating costs Disposal Group, Including Discontinued Operation, Property Operating Costs Disposal Group, Including Discontinued Operation, Property Operating Costs General and administrative Disposal Group, Including Discontinued Operation, General and Administrative Expense Expenses Disposal Group, Including Discontinued Operation, Operating Expense Other income/(expense) Other Income and Expenses [Abstract] Operating loss Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Operating distributions received from unconsolidated joint ventures Proceeds from Equity Method Investment, Dividends or Distributions Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation Depreciation Amortization of debt issuance costs Amortization of Financing Costs and Discounts Loss on settlement of forward starting interest rate swaps Deferred Gain/(Loss) on Settlement of Interest Rate Derivative Gain/(Loss) on settlement of interest rate derivative which is recorded as component of accumulated other comprehensive income and recognized as offset/increase to interest expense over the life of the respective underlying debt facility. Other amortization Amortization of Intangible Assets Stock compensation expense Share-based Compensation Equity in income of unconsolidated joint ventures Income (Loss) from Equity Method Investments, Actual Cash Impact Income (Loss) from Equity Method Investments, Actual Cash Impact Gain on sale of real estate assets Gain (Loss) on Disposal of Real Estate Assets Non Cash Impact Represents the total non-cash gain/loss from sales of real estate assets, including property sales which meet the definition of discontinued operations and property sales which do not meet the definition of discontinued operations under ASC No. 2014-08 Changes in assets and liabilities: Increase (Decrease) in Operating Assets [Abstract] Increase in tenant and straight-line rent receivables, net Increase (Decrease) in Accounts Receivable Decrease/(increase) in restricted cash and escrows Increase (Decrease) in Restricted Cash for Operating Activities Increase in prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Decrease in accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities (Decrease)/increase in deferred income Increase (Decrease) in Deferred Revenue Net cash provided by operating activities Acquisition of real estate assets and related intangibles Payments to Acquire Real Estate Capitalized expenditures, net of accruals Payments for Tenant Improvements, Capital Improvements, and to Develop Real Estate Assets Payments for Tenant Improvements, Capital Improvements, and to Develop Real Estate Assets Debt issuance costs paid Payments of Debt Issuance Costs Costs of issuance of common stock Supplemental Disclosures of Significant Noncash Investing and Financing Activities: Supplemental Cash Flow Information [Abstract] Change in accrued share repurchases as part of an announced plan Increase (Decrease) in Accrued Stock Repurchases Increase (Decrease) in Accrued Stock Repurchases Accrued capital expenditures and deferred lease costs Increase Decrease In Accrued Capital Expenditures And Deferred Lease Costs Net change in the balance of accrued lease acquisition costs and accrued capital expenditures during the period. These accrued costs consist of items such as leasing commissions, lease incentives, procurement fees, tenant improvements, and/or general building improvements. Accrued deferred financing costs Debt Issuance Costs Incurred During Noncash or Partial Noncash Transaction Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block] Schedule of Interest Rate Derivatives Schedule of Interest Rate Derivatives [Table Text Block] Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] Impairment Loss on Real Estate Assets Asset Impairment Charges [Text Block] Variable Interest Entities Variable Interest Entity Disclosure [Text Block] Subsequent Events Subsequent Events [Text Block] Fair Value Measurement of Financial Instruments Fair Value Disclosures [Text Block] Earnings Per Share Earnings Per Share [Text Block] Buildings and improvements, less accumulated depreciation of $919,863 and $889,857 as of June 30, 2016 and December 31, 2015, respectively Intangible lease assets, less accumulated amortization of $95,908 and $93,012 as of June 30, 2016 and December 31, 2015, respectively Investments in and amounts due from unconsolidated joint ventures Tenant receivables, net of allowance for doubtful accounts of $141 and $83 as of June 30, 2016 and December 31, 2015, respectively Accounts Receivable, Net Straight-line rent receivables Deferred Rent Receivables, Net Restricted cash and escrows Restricted Cash and Cash Equivalents Prepaid expenses and other assets Prepaid Expense and Other Assets Deferred lease costs, less accumulated amortization of $157,609 and $146,700 as of June 30, 2016 and December 31, 2015, respectively Unsecured debt, net of discount and unamortized debt issuance costs of $11,551 and $12,779 as of June 30, 2016 and December 31, 2015, respectively Unsecured Debt Secured debt, net of premiums and unamortized debt issuance costs of $1,249 and $1,319 as of June 30, 2016 and December 31, 2015, respectively Secured Debt Intangible lease liabilities, less accumulated amortization of $45,130 and $42,315 as of June 30, 2016 and December 31, 2015, respectively Commitments and Contingencies Commitments and Contingencies Shares-in-trust, 150,000,000 shares authorized; none outstanding as of June 30, 2016 or December 31, 2015 Common Stock Held in Trust Preferred stock, no par value, 100,000,000 shares authorized; none outstanding as of June 30, 2016 or December 31, 2015 Preferred Stock, Value, Issued Common stock, $.01 par value, 750,000,000 shares authorized; 145,229,642 and 145,511,644 shares issued and outstanding as of June 30, 2016 and December 31, 2015, respectively Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures Disposal Groups, Including Discontinued Operations [Table Text Block] Disclosure of Long Lived Assets Held-for-sale Disclosure of Long Lived Assets Held-for-sale [Table Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Tenant receivables, net [Member] Trade Accounts Receivable [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Value [Member] Reported Value Measurement [Member] Estimated Fair Value [Member] Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Receivables Receivables, Fair Value Disclosure Restricted cash and escrows Restricted Cash and Escrows, Fair Value Disclosure This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of restricted cash and escrows existing as of the balance sheet date. Accounts payable and accrued expenses Accounts Payable, Fair Value Disclosure Interest rate swap liability Debt Notes Payable, Fair Value Disclosure Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Condensed Consolidated Balance Sheets Condensed Balance Sheet [Table Text Block] Condensed Consolidated Statements of Income Condensed Income Statement [Table Text Block] Condensed Consolidated Statements of Cash Flows Condensed Cash Flow Statement [Table Text Block] Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Performance Share Program Award [Member] Award Date [Axis] Award Date [Axis] Award Date [Domain] Award Date [Domain] Deferred Stock Award, Granted January 3, 2014 [Member] Deferred Stock Award, Granted January 3, 2014 [Member] Deferred Stock Award, Granted January 3, 2014 [Member] Deferred Stock Award, Granted May 9, 2014 [Member] Deferred Stock Award, Granted May 9, 2014 [Member] Deferred Stock Award, Granted May 9, 2014 [Member] Performance Share Program Award, Granted May 9, 2014 [Member] Performance Share Program Award, Granted May 9, 2014 [Member] Performance Share Program Award, Granted May 9, 2014 [Member] Deferred Stock Award, Granted May 1, 2015 [Member] Deferred Stock Award, Granted May 1, 2015 [Member] Deferred Stock Award, Granted May 1, 2015 [Member] Performance Share Program Award, Granted May 1, 2015 [Member] Performance Share Program Award, Granted May 1, 2015 [Member] Performance Share Program Award, Granted May 1, 2015 [Member] Deferred Stock Award, Granted May 12, 2016 [Member] Deferred Stock Award, Granted May 12, 2016 [Member] Deferred Stock Award, Granted May 12, 2016 [Member] Deferred Stock Award, Granted May 24, 2016 [Member] Deferred Stock Award, Granted May 24, 2016 [Member] Deferred Stock Award, Granted May 24, 2016 [Member] Performance Share Program Award, Granted May 24, 2016 [Member] Performance Share Program Award, Granted May 24, 2016 [Member] Performance Share Program Award, Granted May 24, 2016 [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Share-based Compensation Award, Tranche One [Member] Share-based Compensation Award, Tranche One [Member] Share-based Compensation Award, Tranche Two [Member] Share-based Compensation Award, Tranche Two [Member] Share-based Compensation Award, Tranche Three [Member] Share-based Compensation Award, Tranche Three [Member] Share-based Compensation Award, Tranche Four [Member] Share-based Compensation Award, Tranche Four [Member] Share-based Compensation Award, Tranche Four [Member] Share-based Compensation Award, Tranche Five [Member] Share-based Compensation Award, Tranche Five [Member] Share-based Compensation Award, Tranche Five [Member] Net Shares Granted Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Net Shares Granted The number of share grants, net of shares surrendered for taxes, made on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Grant Date Fair Value Vesting percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Unvested Shares Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Equity Award [Domain] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Independent Directors [Member] Director [Member] Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Compensation expense related to stock awards Allocated Share-based Compensation Expense Amortization of unvested shares Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Amortization Of Nonvested Shares Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Amortization Of Nonvested Shares Total shares issued to employees, directors, and officers Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Unrecognized compensation cost related to nonvested Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Unrecognized compensation cost related to nonvested, weighted-average vesting period (in years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition