Subsequent Events [Abstract] Fair Value Measurement of Financial Instruments [Abstract] Fair Value Measurement of Financial Instruments [Abstract] Fair Value Measurement of Financial Instruments Fair Value Disclosures [Text Block] Notes Receivable [Abstract] Notes Receivable [Abstract] Notes Receivable Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Stockholders' Equity Attributable to Parent [Abstract] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Legal Entity [Axis] Entity [Domain] Statement [Line Items] Statement [Line Items] Revenues: Revenues [Abstract] Rental income Operating Leases, Income Statement, Lease Revenue Tenant reimbursements Tenant Reimbursements Property management fee revenue Management Fees Revenue Other rental income Gain (Loss) on Contract Termination 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. 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 Interest and other (expense)/income Other Nonoperating Income Equity in income of unconsolidated joint ventures Income (Loss) from Equity Method Investments (Loss)/gain on consolidation of variable interest entity Variable Interest Entity, Initial Consolidation, Gain (Loss) Nonoperating 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 income Disposal Group, Including Discontinued Operation, Operating Income (Loss) Impairment loss Disposal Group, Including Discontinued Operation, Loss on Write Down Disposal Group Including Discontinued Operation Loss on Write Down Income/(loss) from discontinued operations Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Less: Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to Piedmont Net Income (Loss) Attributable to Parent Per share information - basic and diluted: Earnings Per Share [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Basic and Diluted Share Income/(loss) from discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations, Net of Tax, Per Basic and Diluted Share Income attributable to noncontrolling interest (in dollars per share) Income (Loss) Attributable To Noncontrolling Interest Net Of Tax Per Basic And Diluted Share Income (Loss) Attributable to Noncontrolling Interest Net of Tax per each basic and diluted share of common stock or unit when the per share amount is the same for both basic and diluted shares. Net income available to common stockholders (in dollars per share) Earnings Per Share, Basic and Diluted Weighted-average common shares outstanding - basic Weighted Average Number of Shares Outstanding, Basic Weighted-average common shares outstanding - diluted Weighted Average Number of Shares Outstanding, Diluted Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Operating distributions received from unconsolidated joint ventures 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 deferred financing costs and fair market value adjustments on notes payable Amortization of Financing Costs Other amortization Amortization of Intangible Assets Impairment loss Accretion of notes receivable discount Accretion (Amortization) of Discounts and Premiums, Investments Stock compensation expense Share-based Compensation Equity in income of unconsolidated joint ventures Gain on consolidation of variable interest entity Changes in assets and liabilities: Increase (Decrease) in Operating Assets [Abstract] (Increase)/decrease in tenant receivables, net Increase (Decrease) in Accounts Receivable 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)/increase in accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Decrease in deferred income Increase (Decrease) in Deferred Revenue 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] Investments in real estate assets Payments for Capital Improvements Cash assumed upon consolidation of variable interest entity Assets Assumed Upon Consolidation Of Variable Interest Entity Net assets received as cash upon consolidation of a variable interest entity ("VIE"). Net sales proceeds received from unconsolidated joint ventures Proceeds from Sale of Equity Method Investments Investments in unconsolidated joint ventures Payments to Acquire Equity Method Investments Deferred lease costs paid Increase (Decrease) in Lease Acquisition Costs Net cash 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] Deferred financing costs paid Payments of Financing Costs Proceeds from line of credit and notes payable Proceeds from Notes Payable Repayments of line of credit and notes payable Repayments of Notes Payable Net proceeds from issuance of common stock Proceeds from Issuance of Common Stock Redemption of fractional shares of common stock Payments for Repurchase of Common Stock Dividends paid and discount on dividend reinvestments Payments of Dividends Common Stock and Discount on Dividend Reinvestments Sum of a) The cash outflow from the distribution of an entity's earnings in the form of dividends to common shareholders, and b) Discount on dividend reinvestments. Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net (decrease)/increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Supplemental Disclosures of Significant Noncash Investing and Financing Activities: Supplemental Cash Flow Information [Abstract] Chage in accrued offering costs Increase (Decrease) in Deferred Offering Costs Change in specific incremental costs directly attributable to a proposed or actual offering of securities which are deferred at the end of the reporting period. Accrued capital expenditures and deferred lease costs Increase Decrease In Accrued Capital Expenditures AndDeferred 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. Net assets assumed upon consolidation of variable interest entity, net of notes receivable previously recorded Net Assets Assumed Upon Consolidation Of Variable Interest Entity, Net Of Notes Receivable Previously Recorded Net Assets within a variable interest entity ("VIE") structure assumed at estimated fair market value, net of notes receivable previously recorded. Liabilities assumed upon consolidation of variable interest entity Liabilities Assumed Upon Consolidation Of Variable Interest Entity Liabilities within a variable interest entity ("VIE") structure assumed at estimated fair market value. Redeemable common stock Redeemable Common Stock Value Change in redeemable common stock value during the period. Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Interest Rate Swap [Member] Interest Rate Cap [Member] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Fair Value, Disclosure Item Amounts [Domain] Fair Value, Disclosure Item Amounts [Domain] Carrying (Reported) Amount, Fair Value Disclosure [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] Estimate of Fair Value, Fair Value Disclosure [Member] Estimate of Fair Value, Fair Value Disclosure [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 Tenant receivables, net Receivables, Fair Value Disclosure Accounts Payable Accounts Payable, Fair Value Disclosure Interest rate swap agreements Interest Rate Cash Flow Hedge Liability at Fair Value Line of credit and notes payable Notes Payable, Fair Value Disclosure Line of Credit and Notes Payable [Abstract] Line of Credit and Notes Payable [Abstract] Schedule of Debt Instruments [Table] Schedule of Debt Instruments [Table] Schedule of Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument, Name [Domain] Fixed-Rate $45 Million Loan [Member] Fixed-Rate 45Million Loan [Member] Fixed-Rate 45Million Loan [Member] Mortgage Note, 35 West Wacker Building [Member] Mortgage Note, 35 West Wacker Building [Member] Aon Center Chicago, 4.87% Mortgage Note [Member] Aon Center Chicago 4.87 Mortgage Note [Member] Aon Center Chicago 4.87 Mortgage Note [Member] Aon Center Chicago, 5.70% Mortgage Note [Member] Aon Center Chicago 5.70 Mortgage Note [Member] Aon Center Chicago 5.70 Mortgage Note [Member] Secured Pooled Facility [Member] Secured Pooled Facility [Member] Fixed-Rate $105 Million Loan [Member] Fixed-Rate 105Million Loan [Member] Fixed-Rate 105Million Loan [Member] Fixed-Rate $125 Million Loan [Member] Fixed-Rate 125Million Loan [Member] Fixed-Rate 125Million Loan [Member] Fixed-Rate $42.5 Million Loan [Member] Fixed-Rate 42.5Million Loan [Member] Fixed-Rate 42.5Million Loan [Member] WDC Mortgage Notes [Member] WDC Mortgage Notes [Member] Mortgage Loan, 500 W. Monroe Building [Member] W. Monroe, 500 Mortgage Loan [Member] Mezzanine I Loan-A Participation, 500 W. Monroe Building [Member] W. Monroe, 500 Mezzanine I Loan-A Participation [Member] Unsecured $250 Million Term Loan [Member] Unsecured 250Million Term Loan [Member] Unsecured 250Million Term Loan [Member] Unsecured $500 Million Facility [Member] Unsecured 500Million Facility [Member] Unsecured 500Million Facility [Member] Long-term and Short-term Debt, Type [Axis] Long-term and Short-term Debt, Type [Axis] Long-term and Short-term Debt, Type [Domain] Long-term and Short-term Debt, Type [Domain] Secured Debt [Member] Unsecured Debt [Member] Debt Instrument [Line Items] Debt Instrument, Face Amount Debt Instrument, Face Amount Rate Debt Instrument, Interest Rate, Stated Percentage Debt, Weighted Average Interest Rate Debt, Weighted Average Interest Rate Line of credit and notes payable, outstanding Notes and Loans Payable Interest Payments on Debt Facilities Interest Paid, Net Debt Instrument, Unamortized Discount Debt Instrument, Unamortized Discount Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Basis Spread on Variable Rate Derivative, Cap Interest Rate Derivative, Cap Interest Rate LIBOR Interest Rate In Effect LIBOR Interest Rate In Effect LIBOR Interest Rate In Effect Line Of Credit Facility Extension Period Line Of Credit Facility Extension Period Line of Credit Facility, Extension Fee Percentage Line of Credit Facility, Extension Fee Percentage Debt Instrument, Description of Variable Rate Basis Accounting Policies [Abstract] Income Tax, Policy Income Tax, Policy [Policy Text Block] Derivatives, Methods of Accounting, Hedging Derivatives Derivatives, Methods of Accounting, Hedging Derivatives [Policy Text Block] Earnings Per Share Earnings Per Share [Text Block] Commitments and Contingencies [Abstract] Commitments and Contingencies Abstract Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Subsequent Event [Table] Subsequent Event [Table] Report Date [Axis] Financial Statements Date [Domain] Date 2011-06-30 [Member] Date 2011-06-30 [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Financing [Member] Financing [Member] Dividend Declared [Member] Dividend Declared [Member] Discontinued Operation or Asset Disposal [Member] Discontinued Operation or Asset Disposal [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Percent of Ownership Interest in Real Estate Property Disposal Percent of Ownership Interest In Real Estate Property Disposal Percent of Ownership Interest In Real Estate Property Disposal Real Estate Property Disposal, Sale Price Real Estate Property Disposal Sale Price Real Estate Property Disposal, Sale Price Dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared Statement of Stockholders' Equity [Abstract] Statement, Equity Components [Axis] Statement, 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] Redeemable Common Stock [Member] Redeemable Common Stock [Member] Redeemable Common Stock [Member] Other Comprehensive Loss [Member] Accumulated Other Comprehensive Income (Loss) [Member] Non-controlling Interest [Member] Noncontrolling Interest [Member] Balance, shares Common Stock, Shares, Outstanding Balance, value Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Offering costs associated with issuance of common stock Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Net proceeds from issuance of common stock, shares Stock Issued During Period, Shares, New Issues Net proceeds from issuance of common stock, value Stock Issued During Period, Value, New Issues Redemption of fractional shares of common stock, shares Stock Redeemed or Called During Period, Shares Redemption of fractional shares of common stock, value Stock Redeemed or Called During Period, Value Change in redeemable common stock outstanding Additional Paid In Capital, Change In Redeemable Common Stock Outstanding The change in the value reclassified as Redeemable Common Stock. Dividends to common stockholders ($1.26 (YTD 2010) and $0.63 (YTD 2011) per share), distributions to noncontrolling interest, 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 by the entity. Shares issued under the 2007 Omnibus Incentive Plan, net of tax, shares Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Shares issued under the 2007 Omnibus Incentive Plan, net of tax, value Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Net income attributable to noncontrolling interest Components of comprehensive income: Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Net income Net change in interest rate swap/derivatives Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Balance, value Balance, shares Schedule of Debt Schedule of Debt [Table Text Block] Discontinued Operations [Abstract] Discontinued Operations [Abstract] Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Weighted-average common shares – basic Restricted stock awards Incremental Common Shares Attributable to Share-based Payment Arrangements Weighted-average common shares – diluted Derivative Instruments [Abstract] Derivative Instruments [Abstract] Derivative [Table] Derivative [Table] Derivative Instruments, Gain (Loss) by Income Statement Location [Axis] Interest Expense [Member] Interest Rate Contract [Member] Interest Rate Cap 1 [Member] Interest Rate Cap 1 [Member] Interest Rate Cap 2 [Member] Interest Rate Cap 2 [Member] Derivative [Line Items] Derivative [Line Items] Notional Amount Notional Amount of Interest Rate Cash Flow Hedge Derivatives Amount of 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 Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Interest Rate Fair Value Hedge Derivative at Fair Value, Net Interest Rate Fair Value Hedge Derivative at Fair Value, Net Number of Interest Rate Derivatives Held Acquisitions [Abstract] Acquisitions [Abstract] Schedule of Business Acquisitions, by Acquisition Schedule of Business Acquisitions, by Acquisition [Table Text Block] Organization [Abstract] Organization Abstract Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol 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 Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Subsequent Events Subsequent Events [Text Block] Stock Based Compensation [Abstract] Stock Based Compensation [Abstract] Stock Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Variable Interest Entities [Abstract] Variable Interest Entities [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Variable Interest Entities by Classification of Entity [Axis] Variable Interest Entities by Classification of Entity [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Primary Beneficiary [Member] Eye Street 1201 NW Associates LLC [Member] Eye Street 1201 NW 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] Suwanee Gateway One LLC [Member] Suwanee Gateway One LLC [Member] Medici Atlanta LLC [Member] Medici Atlanta LLC [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Net Carrying Amount Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net Piedmont’s % Ownership of Entity Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Variable Interst Entity, Cash Flow Percent Entitled To Entity Variable Interst Entity Cash Flow Percent Entitled To Entity Variable Interst Entity Cash Flow Percent Entitled To Entity Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] 1200 Enclave Parkway Building [Member] Enclave Parkway Building, 1200 [Member] 1200 Enclave Parkway Building [Member] The Dupree Building [Member] The Dupree Building [Member] The Medici Building [Member] The Medici Building [Member] 500 W. Monroe Building [Member] W. Monroe Building, 500 [Member] W. Monroe Building, 500 [Member] Business Acquisition [Line Items] Number of Buildings Number Of Buildings In Real Estate Properties Number Of Buildings In Real Estate Properties Rentable Square Feet Square Footage Of Rentable Real Estate Property Square Footage Of Rentable Real Estate Property Percentage Occupied as of Acquisition Date Real Estate Properties Leased, Percent Real Estate Properties Leased Percent Acquisition Price Business Acquisition, Cost of Acquired Entity, Purchase Price Schedule of Letters of Credit Schedule of Letters of Credit [Table Text Block] Schedule of Letters of Credit [Table Text Block] Schedule of Weighted Average Number of Shares Schedule of Weighted Average Number of Shares [Table Text Block] Income Tax For Real Estate Investment Trusts [Table] Income Tax For Real Estate Investment Trusts [Table] Income Tax For Real Estate Investment Trusts [Table] Range [Axis] Range [Domain] Minimum [Member] Income Tax For Real Estate Investment Trusts [Line Items] Income Tax For Real Estate Investment Trusts [Line Items] Real Estate Investment Trust Status Required Taxable Income Distribution Rate Real Estate Investment Trust Status Required Taxable Income Distribution Rate Real Estate Investment Trust Status Required Taxable Income Distribution Rate Disclosure of Long Lived Assets Held-for-sale Disclosure of Long Lived Assets Held-for-sale [Table Text Block] Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Real Estate Properties By Type [Axis] Real Estate Properties By Type [Axis] Real Estate Properties Type [Domain] Real Estate Properties Type [Domain] Office properties [Member] Office properties [Member] Building [Member] Industrial buildings [Member] Industrial buildings [Member] Joint Venture [Member] Joint Venture [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] Number of Real Estate Properties Number of Real Estate Properties Number of Metropolitan Areas Number of Metropolitan Areas In Which Entity Operates Number of Metropolitan Areas In Which Entity Operates Square Footage of Real Estate Property Real Estate Properties Leased, Percent Variable Interest Entities Variable Interest Entity, Similar Entity Aggregation, Description Line of Credit and Notes Payable Debt Disclosure [Text Block] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Axis] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Disposal Groups, Including Discontinued Operations, Name [Domain] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale, Name [Domain] Land [Member] Building Improvements [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] Real estate assets held for sale, net: Real Estate Held for Development and Sale, Net [Abstract] Property, Plant, and Equipment, Net Disposal Group, Including Discontinued Operation, Property, Plant, and Equipment, Net Property, Plant, and Equipment, Accumulated Depreciation Disposal Group, Including Discontinued Operation, Accumulated Depreciation, Property Plant and Equipment Disposal Group, Including Discontinued Operation, Accumulated Depreciation, Property Plant and Equipment Real estate assets held for sale, net Real Estate Held-for-sale Other assets held for sale: Other Assets Held For Sale [Abstract] Other assets held for sale [Abstract] Tenant receivables Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Deferred lease costs, Net Disposal Group Including Discontinued Operation Deferred Lease Costs Net Disposal Group Including Discontinued Operation Deferred Lease Costs Net Deferred Lease Costs, Accumulated Amortization Disposal Group, Including Discontinued Operation, Deferred Lease Costs, Accumulated Amortization Disposal Group, Including Discontinued Operation, Deferred Lease Costs, Accumulated Amortization Other assets held for sale Disposal Group, Including Discontinued Operation, Other Assets Rental Income Disposal Group, Including Discontinued Operation, Rental Income Disposal Group, Including Discontinued Operation, Rental Income Tenant Reimbursement 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 Depreciation Disposal Group, Including Discontinued Operation, Depreciation Disposal Group, Including Discontinued Operation, Depreciation Amortization of deferred leasing costs Disposal Group, Including Discontinued Operation, Amortization Disposal Group, Including Discontinued Operation, Amortization General and administrative expense Disposal Group, Including Discontinued Operation, General and Administrative Expense Disposal Group, Including Discontinued Operation, General and Administrative Expense Other expense Disposal Group, Including Discontinued Operation, Other Expense Disposal Group, Including Discontinued Operation, Other Expense Expenses Disposal Group, Including Discontinued Operation, Cost and Expense Disposal Group, Including Discontinued Operation, Cost and Expense Notes Receivable and Variable Interest Entity [Table] Notes Receivable and Variable Interest Entity [Table] Notes Receivable and Variable Interest Entity [Table] Component of Other Income, Nonoperating [Axis] Component of Other Income, Nonoperating, Name [Domain] Operating Cash Flow On Foreclosed Property [Member] Operating Cash Flow On Foreclosed Property [Member] Variable Interest Entity, Initial Consolidation, Gain (Loss) Number of Investments Number of Investments Number of Notes Receivable Matured Number of Notes Receivable Matured Number of Notes Receivable Number of Notes Receivable Other Nonoperating Income Statement of Financial Position [Abstract] Assets: Assets [Abstract] Land Land Buildings and improvements, less accumulated depreciation of $789,718 and $741,723 as of June 30, 2011 and December 31, 2010, respectively Investment Building and Building Improvements, Net Investment Building and Building Improvements, Net Intangible lease assets, less accumulated amortization of $136,180 and $145,742 as of June 30, 2011 and December 31, 2010, respectively Finite-Lived Intangible Assets, Net Construction in progress Construction in Progress, Gross Total real estate assets Real Estate Investment Property, Net Investments in unconsolidated joint ventures Equity Method Investments Cash and cash equivalents Tenant receivables, net of allowance for doubtful accounts of $921 and $1,298 as of June 30, 2011 and December 31, 2010, respectively Accounts Receivable, Net Notes receivable Notes, Loans and Financing Receivable, Net Due from unconsolidated joint ventures Due from Joint Ventures Restricted cash and escrows Restricted Cash and Cash Equivalents Prepaid expenses and other assets Prepaid Expense and Other Assets Goodwill Goodwill Deferred financing costs, less accumulated amortization of $10,856 and $11,893 as of June 30, 2011 and December 31, 2010, respectively Deferred Finance Costs, Net Deferred lease costs, less accumulated amortization of $137,378 and $136,923 as of June 30, 2011 and December 31, 2010, respectively Deferred Costs, Leasing, Net Other assets held for sale Total assets Assets Liabilities: Liabilities [Abstract] Line of credit and notes payable Notes Payable Accounts payable, accrued expenses, and accrued capital expenditures Accounts Payable and Accrued Liabilities Deferred income Deferred Revenue Intangible lease liabilities, less accumulated amortization of $88,444 and $84,308 as of June 30, 2011 and December 31, 2010, respectively Off-market Lease, Unfavorable Interest rate swap Total liabilities Liabilities Commitments and Contingencies Stockholders' Equity: Shares-in-trust, 150,000,000 shares authorized, none outstanding as of June 30, 2011 or December 31, 2010 Common Stock Held in Trust Preferred stock, no par value, 100,000,000 shares authorized, none outstanding as of June 30, 2011 or December 31, 2010 Preferred Stock, Value, Issued Common stock, $.01 par value, 750,000,000 shares authorized; 172,826,725 and 172,658,489 shares issued and outstanding as of June 30, 2011 and December 31, 2010, respectively (Note 12) 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 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 Total liabilities and stockholders' equity Liabilities and Equity Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Notional Amounts of Outstanding Derivative Positions Schedule of Notional Amounts of Outstanding Derivative Positions [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] Acquisitions Business Combination Disclosure [Text Block] Loss Contingencies [Table] Letter of Credit Agreements by Expiration Date [Axis] Letter of Credit Agreements by Expiration Date [Axis] Letter of Credit Agreements by Expiration Date [Domain] Letter of Credit Agreements by Expiration Date [Domain] Letter of Credit 1, February 2012 [Member] Letter of Credit, February 2012 [Member] Letter of Credit 2, February 2012 [Member] Letter of Credit 2, February 2012 [Member] Letter of Credit, December 2011 [Member] Letter of Credit, December 2011 [Member] Loss Contingencies by Nature of Contingency [Axis] Loss Contingency, Nature [Domain] Collectibility of Tenant Reimbursements [Member] Collectibility of Tenant Reimbursements [Member] Loss Contingencies [Line Items] Commitment to Provide Funding to Tenants for Capital Improvements Commitment to Provide Funding to Tenants for Capital Improvements Commitment to Provide Funding to Tenants for Capital Improvements Commitment To Provide Funding To Tenants For Capital Improvements Period Commitment To Provide Funding To Tenants For Capital Improvements Period Loss Contingency Accrual, Carrying Value, Provision Loss Contingency Accrual, Carrying Value, Provision Loss Contingency Recovery Loss Contingency Recovery Loss Contingency Recovery Letters of Credit Outstanding, Amount Letters of Credit Outstanding, Amount Number of Lawsuits as Defendant Number of Lawsuits as Defendant Letter of Credit Renewal Period Letter of Credit Renewal Period Schedule of Nonvested Share Activity Schedule of Nonvested Share Activity [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] Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] Share-based Compensation Arrangements by Share-based Payment Award, Award Type and Plan Name [Domain] Share-based Compensation Arrangements by Share-based Payment Award, Award Type and Plan Name [Domain] Stock Awards [Member] Stock Awards [Member] Stock Awards, Granted May 6, 2009 [Member] Stock Awards, Granted May 6, 2009 [Member] Stock Awards 1, Granted May 24, 2010 [Member] Stock Awards 1, Granted May 24, 2010 [Member] Stock Awards 2, Granted May 24, 2010 [Member] Stock Awards 2, Granted May 24, 2010 [Member] Stock Awards, Granted April 5, 2011 [Member] Stock Awards, Granted April 5, 2011 [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Allocated Share-based Compensation Expense Allocated Share-based Compensation Expense 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 Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Amortization Of Nonvested Shares Net Shares Granted Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants Net On Reported Date Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Grants, Net, On Reported Date Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Unvested Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Of the shares granted, % vested Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested Percent At Reported Date Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Vested Percent At Reported Date Of the shares granted, % expected to vest Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Percent At Reported Date Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected To Vest Percent At Reported Date Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition Note 11 Parenthetical [Abstract] Note 11 Parenthetical [Abstract] Consolidated Balance Sheets Parenthetical [Abstract] Consolidated Balance Sheets Parenthetical [Abstract] Property, Plant and Equipment by Type [Axis] Property, Plant and Equipment, Type [Domain] Building and Building Improvements [Member] Assets: Real Estate Investment Property, 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 financing costs, accumulated amortization Accumulated Amortization, Deferred Finance Costs Deferred lease costs, accumulated amortization Deferred Costs, Leasing, Accumulated Amortization Intangible Lease Liabilities, Accumulated Amortization Intangible Lease Liabilities, Accumulated Amortization The amount of accumulated amortization related to unfavorable real estate leases. 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 Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares outstanding Dividends to common stockholders per share