Variable Interest Entities [Abstract] Variable Interest Entities [Abstract] Variable Interest Entities Variable Interest Entities [Text Block] Describes how the entity aggregates Variable Interest Entities (VIE) for disclosure purposes, distinguishing between (a) VIEs that are not consolidated because the enterprise is not the primary beneficiary but has a variable interest and (b) VIEs that are consolidated Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Commitments and Contingencies Disclosure [Abstract] 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] 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] Wells REIT Multi-State Owner, LLC [Member] Wells REIT Multi-State Owner, LLC [Member] Wells REIT Multi-State Owner, 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] TownPark 400, LLC [Member] TownPark 400, LLC [Member] TownPark 400, 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 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 Disclosure of Compensation Related Costs, Share-based Payments [Abstract] 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 [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 [Roll Forward] Unvested Deferred 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 Adjustment to Estimated Future Grants of Performance Share Awards (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Adjustment to Estimated Future Grants in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Adjustment to Estimated Future Grants in Period 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 Deferred Stock Awards, End of period (in shares) Unvested Deferred 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 Adjustment to Estimated Future Grants of 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, Adjustment to Estimated Future Grants in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Adjustment to Estimated Future Grants in Period, Weighted Average Grant Date Fair Value 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, Forfeited in Period, Weighted Average Grant Date Fair Value Unvested Deferred Stock Awards, Weighted-Average Grant Date Fair Value, End of period (in dollars per share) Derivative Instruments [Abstract] Derivative Instruments [Abstract] 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] Organization [Abstract] Organization Abstract 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] Industrial buildings [Member] Industrial buildings [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 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 Square Footage of Real Estate Property Real Estate Properties Leased, Percent Real Estate Properties Leased, Percent Real Estate Properties Leased Percent 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] Derivative Instrument Risk [Axis] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Derivative Contract Type [Domain] Interest Rate Swap [Member] Interest Rate Swap [Member] 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 $200 Million [Member] Aon Center Chicago 4.87 Mortgage Note [Member] Aon Center Chicago 4.87 Mortgage Note [Member] Mortgage Note $25 Million [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 $140 Million[Member] WDC Mortgage Notes [Member] WDC Mortgage Notes [Member] 500 W. Monroe Mortgage Loan $140 Million [Member] Mortgage Loan, 500 W. Monroe Building [Member] W. Monroe, 500 Mortgage Loan [Member] Unsecured $300 Million Term Loan [Member] Unsecured 300 Million Term Loan [Member] $300 Million Unsecured 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 Notes and Loans Payable Notes and Loans Payable Debt, Weighted Average Interest Rate Debt, Weighted Average Interest Rate Number Of Properties In Collateralized Pool Number Of Properties In Collateralized Pool Number Of Properties In Collateralized Pool Debt Instrument, Interest Rate, Effective Percentage Debt Instrument, Interest Rate, Effective Percentage Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Basis Spread on Variable Rate LIBOR Interest Rate In Effect LIBOR Interest Rate In Effect LIBOR Interest Rate In Effect Discontinued Operations [Abstract] Discontinued Operations [Abstract] Schedule of Disposal Groups, Including Discontinued Operations, Results Of Operations Schedule of Disposal Groups, Including Discontinued Operations, Results Of Operations [Table Text Block] Schedule of Disposal Groups, Including Discontinued Operations, Results Of Operations [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] Income Statement [Abstract] Statement [Table] Statement [Table] 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 income (expense) Other Nonoperating Income Equity in income of unconsolidated joint ventures Income (Loss) from Equity Method Investments Gain (loss) 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) Gain on sale of real estate assets Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax Income 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 Income (Loss) from Continuing Operations Attributable to Noncontrolling Interest Net income attributable to Piedmont Net Income (Loss) Attributable to Parent Per share information – basic: Earnings Per Share, Basic [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Income from discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share Net income available to common stockholders (in dollars per share) Earnings Per Share, Basic Per share information – diluted: Earnings Per Share, Diluted [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Income from discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share Net income available to common stockholders (in dollars per share) Earnings Per Share, 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 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] Eastpointe Corporate Center [Member] Eastpointe Corporate Center [Member] Eastpointe Corporate Center [Member] Corporate Court 5000 [Member] Corporate Court 5000 [Member] Corporate Court 5000 [Member] West Wacker 35 [Member] West Wacker 35 [Member] West Wacker 35 [Member] Portland Portfolio [Member] Portland Portfolio [Member] Portland Portfolio [Member] ENTERPRISE WAY 26200 [Member] ENTERPRISE WAY 26200 [Member] ENTERPRISE WAY 26200 [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 Net Sales Proceeds Proceeds from Divestiture of Businesses, Net of Cash Divested 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 Number of Real Estate Properties Sold Number of Real Estate Properties Sold Number of Real Estate Properties Sold Area of Land (in acres) Area of Land Area of land held. Acres Of Undeveloped Land Sold Acres Of Undeveloped Land Sold Acres Of Undeveloped Land Sold Real Estate Property Disposal, Sale Price Real Estate Property Disposal Sale Price Real Estate Property Disposal, Sale Price Notes receivable received in conjunction with real estate asset sale Notes, Loans and Financing Receivable, Net Notes, Loans and Financing Receivable, Interest Rate Notes, Loans and Financing Receivable, Interest Rate Notes, Loans and Financing Receivable, Interest Rate 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 Expenses Disposal Group, Including Discontinued Operation, Operating Expense Other income (expense): Other Income and Expenses [Abstract] Interest expense Disposal Group, Including Discontinued Operation, Interest Expense Interest and other expense Disposal Group Including Discontinued Operation Interest And Other Income Expense Disposal Group Including Discontinued Operation Interest And Other Income Expense Net income attributable to noncontrolling interest Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest Other income (expense) Disposal Group Including Discontinued Other Income Expense Disposal Group Including Discontinued Other Income Expense Operating income, excluding gain on sale Income from discontinued operations Stock Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Award Vesting Period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Stock Awards, Performance Period Used In Calculation (in years) Stock Awards, Performance Period Used In Calculation Stock Awards, Performance Period Used In Calculation 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 Shares issued to employees, directors, and officers Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Unrecognized compensation cost related to nonvested Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized Unrecognized compensation cost related to nonvested, Period for Recognition (in years) Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition Statement of Income and Comprehensive Income [Abstract] Legal Entity [Axis] Entity [Domain] Net income attributable to Piedmont Other comprehensive loss: Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract] Effective portion of loss on derivative instruments that are designated and qualify as cash flow hedges (See Note 6) Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Less: reclassification of previously recorded loss included in net income (See Note 6) Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax Other comprehensive gain/(loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Comprehensive income attributable to Piedmont Comprehensive Income (Loss), Net of Tax, Attributable to Parent Weighted-average common shares – basic Restricted stock awards (in shares) Incremental Common Shares Attributable to Share-based Payment Arrangements Weighted-average common shares – diluted Receivables [Abstract] Tenant receivables, net of allowance for doubtful accounts of $209 and $631 as of June 30, 2012 and December 31, 2011, respectively Accounts Receivable, Net Tenant receivables, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable Cumulative rental revenue recognized on a straight-line basis in excess of cash received in accordance with lease terms Deferred Rent Receivables, Net Tenant and notes receivable, net Tenant And Notes Receivable Tenant Receivables, Including Straight Line Rental Revenue Receivables, and Notes Receivable. Loss Contingencies [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Maximum [Member] Maximum [Member] 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, December 2012 [Member] Letter of Credit, December 2012 [Member] Letter of Credit, December 2012 [Member] Letter of Credit, February 2013 [Member] Letter of Credit, February 2013 [Member] Letter of Credit, February 2013 [Member] Letter of Credit, July 2013 [Member] Letter of Credit, July 2013 [Member] Letter of Credit, July 2013 [Member] Loss Contingencies by Nature of Contingency [Axis] Loss Contingency, Nature [Domain] Collectibility of Tenant Reimbursements [Member] Collectibility of Tenant Reimbursements [Member] Pending or Threatened Litigation [Member] Pending or Threatened Litigation [Member] Lawsuit One [Member] Lawsuit One [Member] Lawsuit One [Member] Lawsuit Two [Member] Lawsuit Two [Member] Lawsuit Two [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 Loss Contingency, Loss in Period Loss Contingency, Loss in Period Letters of Credit Outstanding, Amount Letters of Credit Outstanding, Amount Letter of Credit Renewal Period Letter of Credit Renewal Period Letter of Credit Renewal Period Number of Lawsuits as Defendant Number of Lawsuits as Defendant Loss Contingency, Number Of Counts Loss Contingency, Number Of Counts Loss Contingency, Number Of Counts Loss Contingency, Number Of Counts Dismissed By Court To Date Loss Contingency, Number Of Counts Dismissed By Court To Date Loss Contingency, Number Of Counts Dismissed By Court To Date Loss Contingency, Damages Sought, Value Loss Contingency, Damages Sought, Value Estimated Insurance Recoveries Estimated Insurance Recoveries Loss Contingency, Range of Possible Loss, Minimum Loss Contingency, Range of Possible Loss, Minimum Loss Contingency, Range of Possible Loss, Maximum Loss Contingency, Range of Possible Loss, Maximum Line of Credit and Notes Payable Debt Disclosure [Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Fair Value Measurement of Financial Instruments [Abstract] Fair Value Measurement of Financial Instruments [Abstract] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Minimum [Member] Minimum [Member] Long-term and Short-term Debt, Type [Axis] Long-term and Short-term Debt, Type [Domain] Unsecured Debt [Member] Secured Debt [Member] Debt Instrument [Axis] Debt Instrument, Name [Domain] Mortgage Loan, 500 W. Monroe Building [Member] Debt Instrument [Line Items] Interest Paid, Net Interest Paid, Net 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 Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Statement, Scenario [Axis] Statement, Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Plan [Member] Scenario, Plan [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] UNDEVELOPED LAND PARCELS [Member] UNDEVELOPED LAND PARCELS [Member] UNDEVELOPED LAND PARCELS [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Purchase Price Business Acquisition, Cost of Acquired Entity, Purchase Price Square footage of site plan 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] Income attributable to noncontrolling interest- discontinued operations Depreciation Depreciation Amortization of deferred financing costs Amortization of Financing Costs and Discounts Other amortization Amortization of Intangible Assets 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 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 Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Non Cash Impact Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Non Cash Impact Gain on consolidation of variable interest entity Changes in assets and liabilities: Increase (Decrease) in Operating Assets [Abstract] Increase in tenant receivables, net Increase (Decrease) in Accounts Receivable Increase in restricted cash and escrows Increase (Decrease) in Restricted Cash for Operating Activities Decrease (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 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 and related intangibles Payments to Acquire Productive Assets 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 from wholly-owned properties Net sales proceeds 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 Costs of issuance of common stock Payments of Stock Issuance Costs Share repurchases as part of an announced program Payments for Repurchase of Common Stock 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 decrease 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] Change in accrued offering costs related to issuance of common stock 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. Change in accrued share repurchases as part of an announced program 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 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. Income Tax, Policy Income Tax, Policy [Policy Text Block] Goodwill, Policy Goodwill and Intangible Assets, Policy [Policy Text Block] Schedule of Nonvested Share Activity Schedule of Nonvested Share Activity [Table Text Block] Schedule of Outstanding Employee Deferred Stock Awards Schedule of Outstanding Employee Deferred Stock Awards [Table Text Block] Schedule of Outstanding Employee Deferred Stock Awards [Table Text Block] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Dividend Declared [Member] Dividend Declared [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Dividends declared (in dollars per share) Common Stock, Dividends, Per Share, Declared 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, Measurements, Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [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 Value [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] Estimated Fair Value [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 and notes receivable, net 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 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 Derivative [Table] Derivative [Table] Derivative Instruments, Gain (Loss) by Income Statement Location [Axis] Income Statement and Other Comprehensive Income (Loss) Location [Domain] Income Statement and Other Comprehensive Income (Loss) Location [Domain] Interest Expense [Member] Interest Rate Swap 1 [Member] Interest Rate Swap 1 [Member] Interest Rate Swap 1 [Member] Interest Rate Swap 2 [Member] Interest Rate Swap 2 [Member] Interest Rate Swap 2 [Member] Interest Rate Swap 3 [Member] Interest Rate Swap 3 [Member] Interest Rate Swap 3 [Member] Interest Rate Swap 4 [Member] Interest Rate Swap 4 [Member] Interest Rate Swap 4 [Member] Credit Risk Contract [Member] Credit Risk Contract [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 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 Assets Needed for Immediate Settlement, Aggregate Fair Value Assets Needed for Immediate Settlement, Aggregate Fair Value Income Tax For Real Estate Investment Trusts [Table] Income Tax For Real Estate Investment Trusts [Table] Income Tax For Real Estate Investment Trusts [Table] 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 Statement of Stockholders' Equity [Abstract] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Dividends to common stockholders per share Common Stock, Dividends, Per Share, Cash Paid Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Schedule of Debt Schedule of Debt [Table Text Block] Acquisitions Business Combination Disclosure [Text Block] Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Statement of Financial Position [Abstract] Assets: Assets [Abstract] Land Land Buildings and improvements, less accumulated depreciation of $837,285 and $792,342 as of June 30, 2012 and December 31, 2011, respectively Investment Building and Building Improvements, Net Investment Building and Building Improvements, Net Intangible lease assets, less accumulated amortization of $82,742 and $119,419 as of June 30, 2012 and December 31, 2011, 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 and notes receivable, net of allowance for doubtful accounts of $209 and $631 as of June 30, 2012 and December 31, 2011, respectively 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 $9,974 and $9,214 as of June 30, 2012 and December 31, 2011, respectively Deferred Finance Costs, Net Deferred lease costs, less accumulated amortization of $120,925 and $120,358 as of June 30, 2012 and December 31, 2011, respectively Deferred Costs, Leasing, Net 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 $68,723 and $63,981 as of June 30, 2012 and December 31, 2011, respectively Off-market Lease, Unfavorable Interest rate swaps Total liabilities Liabilities Commitments and Contingencies Stockholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Shares-in-trust, 150,000,000 shares authorized; none outstanding as of June 30, 2012 or December 31, 2011 Common Stock Held in Trust Preferred stock, no par value, 100,000,000 shares authorized; none outstanding as of June 30, 2012 or December 31, 2011 Preferred Stock, Value, Issued Common stock, $.01 par value, 750,000,000 shares authorized; 170,234,828 and 172,629,748 shares issued and outstanding as of June 30, 2012 and December 31, 2011, respectively 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 Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and stockholders' equity Liabilities and Equity Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Property, Plant and Equipment by Type [Axis] Property, Plant and Equipment by Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Building and Building Improvements [Member] 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 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 the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. 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 Common stock, shares outstanding Common Stock, Shares, Outstanding Fair Value Measurement of Financial Instruments Fair Value Disclosures [Text Block] Tenant and Notes Receivable Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Stock Awards, Granted May 11, 2010 [Member] Stock Awards, Granted May 11, 2010 [Member] Stock Awards, Granted May 11, 2010 [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] Stock Awards 2, Granted April 5, 2011 [Member] Stock Awards 2, Granted April 5, 2011 [Member] Stock Awards 2, Granted April 5, 2011 [Member] Stock Awards 1, Granted April 4, 2012 [Member] Stock Awards 1, Granted April 4, 2012 [Member] Stock Awards 1, Granted April 4, 2012 [Member] Stock Awards 2, Granted April 4, 2012 [Member] Stock Awards 2, Granted April 4, 2012 [Member] Stock Awards 2, Granted April 4, 2012 [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 surrended 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 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 in one year Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected to Vest Within One Year, Percent Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected to Vest Within One Year, Percent Of the shares granted, % expected to vest in two years Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected to Vest In Two Years, Percent Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected to Vest In Two Years, Percent Of the shares granted, % expected to vest in three years Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected to Vest In Three Years, Percent Share Based Compensation Arrangement By Share Based Payment Award, Equity Instruments Other Than Options, Expected to Vest In Three Years, Percent Unvested Shares 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] Other Comprehensive Loss [Member] Accumulated Other Comprehensive Income (Loss) [Member] Non-controlling Interest [Member] Noncontrolling Interest [Member] Balance Balance (in shares) Shares repurchases as part of an announced program Stock Repurchased and Retired During Period, Value Shares repurchases as part of an announced program (in shares) Stock Repurchased and Retired During Period, Shares Offering costs associated with the issuance of common stock Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Attribution of asset sales proceeds to noncontrolling interest Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Dividends to common stockholders ($1.2600 (YTD 2011) and $0.40 (YTD 2012) 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 Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Shares issued under the 2007 Omnibus Incentive Plan, net of tax (in shares) Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Other comprehensive loss Balance Balance (in shares)