Equity [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] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Director Director [Member] Award Date [Axis] Award Date [Axis] Award Date [Domain] Award Date [Domain] January 3, 2017 January 03, 2017 [Member] January 03, 2017 [Member] May 2, 2017 May 02, 2017 [Member] May 02, 2017 [Member] January 4, 2016 January 04, 2016 [Member] January 04, 2016 [Member] April 1, 2016 April 1, 2016 [Member] April 1, 2016 [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Grant-Date Fair Value (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 Equity Method Investments and Joint Ventures [Abstract] Summary of Financial Information for the Market Square Joint Venture Equity Method Investments [Table Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Corporate Joint Venture Corporate Joint Venture [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Hotel Segment Reconciling Items [Member] Corporate Corporate, Non-Segment [Member] Joint Venture Intersegment Eliminations [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] New York New York Segment [Member] New York Segment San Francisco San Francisco Segment [Member] San Francisco Segment Atlanta Atlanta Segment [Member] Atlanta Segment Washington, D.C. Washington, D.C. Segment [Member] Washington, D.C. Segment Boston Boston Segment [Member] Boston Segment Los Angeles Los Angeles Segment [Member] Los Angeles Segment All other office markets All Other Markets Segment [Member] All Other Markets Segment Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Operating revenues including unconsolidated joint venture Revenues, Including Unconsolidated Joint Venture Revenues, Including Unconsolidated Joint Venture Operating revenues Revenues Ownership percentage Equity Method Investment, Ownership Percentage Total revenues Equity Method Investment, Summarized Financial Information, Revenue Net loss Equity Method Investment, Summarized Financial Information, Net Income (Loss) Columbia Property Trust's share of net loss Income (Loss) from Equity Method Investments, Joint Ventures Income (Loss) from Equity Method Investments, Joint Ventures Reconciliation of Revenue from Segments to Consolidated Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Accounting Policies [Abstract] Schedule of Finite-Lived Intangible Assets by Major Class Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Above-Market In-Place Lease Assets Above-Market In-Place Lease Assets [Member] Above-Market In-Place Lease Assets [Member] Absorption Period Costs Absorption Period Costs [Member] Absorption Period Costs [Member] Intangible Lease Origination Costs Intangible Lease Origination Costs [Member] Intangible Lease Origination Costs [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] For the remainder of 2017 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year For the years ending December 31: Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Five 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Six Finite-Lived Intangible Assets, Amortization Expense, Year Six Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Six Finite-Lived Intangible Assets, Amortization Expense, after Year Six Intangible lease assets, net Finite-Lived Intangible Assets, Net Intangible Lease Origination Costs, Net Finite-Lived Intangible Asset, Acquired-in-Place Leases Intangible Below-Market In-Place Lease Liabilities Below Market Lease [Abstract] For the remainder of 2017 Below Market Lease, Amortization Income, Remainder of Fiscal Year For the years ending December 31: Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [Abstract] 2018 Below Market Lease, Amortization Income, Year Two 2019 Below Market Lease, Amortization Income, Year Three 2020 Below Market Lease, Amortization Income, Year Four 2021 Below Market Lease, Amortization Income, Year Five 2022 Below Market Lease, Amortization Income, Year Six Below Market Lease, Amortization Income, Year Six Thereafter Below Market Lease, Amortization Income, after Year Six Below Market Lease, Amortization Income, after Year Six Below Market Lease, Net Below Market Lease, Net Segment Reconciling Items Net income Net Income (Loss) Attributable to Parent Depreciation Depreciation 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 for continuing operations General and administrative General and Administrative Expense Net interest expense Interest Income (Expense), Net Interest income from development authority bonds Interest Income, Development Authority Bonds Interest Income, Development Authority Bonds Loss on early extinguishment of debt Gain (Loss) On Extinguishment of Debt Continuing Operations Gain (Loss) On Extinguishment of Debt Continuing Operations Income tax expense (benefit) Income Tax Expense (Benefit) Adjustments included in loss from unconsolidated joint venture Income (Loss) from Equity Method Investments, Adjustment Income (Loss) from Equity Method Investments, Adjustment Loss (gains) on sales of real estate assets Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes NOI Net Operating Income (Loss) Net Operating Income (Loss) Property, Plant and Equipment [Table] Property, Plant and Equipment [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] Buildings Building [Member] Building Improvements Building Improvements [Member] Intangible Below Market Lease Assets Below-Market Lease Assets [Member] Below-Market Lease Assets [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Estimated useful life of real estate assets Property, Plant and Equipment, Useful Life Gross intangible assets Finite-Lived Intangible Assets, Gross Amortization of intangible assets Amortization of Intangible Assets Hedge ineffectiveness recognized in earnings Gain (Loss) on Interest Rate Fair Value Hedge Ineffectiveness Requirement to distribute taxable income (at least) Requirement to Distribute Taxable Income, Percent Requirement to Distribute Taxable Income, Percent Limit on investments in taxable real estate investment trusts (percent) Limit on Investments in Taxable Real Estate Investment Trusts, Percent Limit on Investments in Taxable Real Estate Investment Trusts, Percent Net operating income (loss) including unconsolidated joint venture Net Operating Income (Loss) Including Unconsolidated Joint Venture Net Operating Income (Loss) Including Unconsolidated Joint Venture Condensed Financial Information of Parent Company Only Disclosure [Abstract] Schedule of Condensed Financial Statements Condensed Financial Statements [Table] Reportable Legal Entities Reportable Legal Entities [Member] Consolidating Adjustments Consolidation, Eliminations [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Columbia Property Trust (Parent) (Guarantor) Parent Company [Member] Columbia Property Trust OP (the Issuer) Subsidiary Issuer [Member] Non- Guarantors Non-Guarantor Subsidiaries [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Net income (loss) Market value adjustment to interest rate swap Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Performance Shares Performance Shares [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Stock Repurchase Program Stock Repurchase Program [Member] Stock Repurchase Program [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2013 Long Term Incentive Plan 2013 Long Term Incentive Plan [Member] 2013 Long Term Incentive Plan [Member] Long Term Incentive Plan Long Term Incentive Plan [Member] Long Term Incentive Plan [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] End of Performance Period Share-based Compensation Award, Tranche Five [Member] Share-based Compensation Award, Tranche Five [Member] One Year Post Performance Period Share-based Compensation Award, Tranche Six [Member] Share-based Compensation Award, Tranche Six [Member] End of Performance Period, One Year Transitional Awards Share-based Compensation Award, Tranche Seven [Member] Share-based Compensation Award, Tranche Seven [Member] End of Performance Period, Two Year Transitional Awards Share-based Compensation Award, Tranche Eight [Member] Share-based Compensation Award, Tranche Eight [Member] Grant Date Share-based Compensation Award, Tranche One [Member] January 31, 2018 Share-based Compensation Award, Tranche Two [Member] January 31, 2019 Share-based Compensation Award, Tranche Three [Member] January 31, 2020 Share-based Compensation Award, Tranche Four [Member] Share-based Compensation Award, Tranche Four [Member] Stock repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Common stock, par value (dollars per share) Common Stock, Par or Stated Value Per Share Number of shares repurchased (in shares) Stock Repurchased During Period, Shares Shares repurchased, average cost per share (dollars per share) Treasury Stock Acquired, Average Cost Per Share Value of stock repurchased Stock Repurchased During Period, Value Stock repurchase program, amount available for repurchase Stock Repurchase Program, Remaining Authorized Repurchase Amount Shares authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Granted (shares) Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Total shareholder return as a percent Share-based Compensation Arrangement by Share-based Payment Award, Shareholder Payout, Percent Share-based Compensation Arrangement by Share-based Payment Award, Shareholder Payout, Percent Performance period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Award vesting rights (percent) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Shares withheld to settle tax liability Shares Paid for Tax Withholding for Share Based Compensation Unrecognized compensation costs related to unvested awards Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Unrecognized compensation costs recognition period (years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Statement of Financial Position [Abstract] Assets: Assets [Abstract] Real estate assets, at cost: Real Estate Investment Property, at Cost [Abstract] Land Land Buildings and improvements, less accumulated depreciation of $471,029 and $435,457, as of June 30, 2017 and December 31, 2016, respectively Investment Building And Building Improvements , Net Aggregate of the carrying amounts as of the balance sheet date of investments in building and building improvements net of accumulated depreciation Intangible lease assets, less accumulated amortization of $99,910 and $112,777, as of June 30, 2017 and December 31, 2016, respectively Construction in progress Construction in Progress, Gross Real estate assets held for sale, less accumulated depreciation and amortization of $180,791, as of December 31, 2016 Real Estate Held-for-sale Total real estate assets Real Estate Investment Property, Net Investment in unconsolidated joint venture Real Estate Investments, Joint Ventures Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Tenant receivables, net of allowance for doubtful accounts of $31 as of December 31, 2016 Accounts and Notes Receivable, Net Straight-line rent receivable Deferred Rent Receivables, Net Prepaid expenses and other assets Prepaid Expense and Other Assets Intangible lease origination costs, less accumulated amortization of $68,771 and $74,578, as of June 30, 2017 and December 31, 2016, respectively Deferred lease costs, less accumulated amortization of $25,838 and $22,753, as of June 30, 2017 and December 31, 2016, respectively Deferred Costs, Leasing, Net Investment in development authority bonds Investment in Development Authority Bonds Investments in development authority bonds which were assumed upon acquisition of certain real estate assets and allow for property tax abatement benefits over the term of the agreement. Other assets held for sale, less accumulated amortization of $34,152, as of December 31, 2016 Disposal Group, Including Discontinued Operation, Assets Total assets Assets Liabilities: Liabilities [Abstract] Line of credit and notes payable, net of unamortized deferred financing costs of $2,614 and $3,136, as of June 30, 2017 and December 31, 2016, respectively Loans Payable Bonds payable, net of discounts of $1,574 and $1,664 and unamortized deferred financing costs of $5,062 and $5,364, as of June 30, 2017 and December 31, 2016, respectively Unsecured Debt Accounts payable, accrued expenses, and accrued capital expenditures Accounts Payable and Accrued Liabilities Dividends payable Dividends Payable Deferred income Deferred Revenue Intangible lease liabilities, less accumulated amortization of $39,939 and $44,564, as of June 30, 2017 and December 31, 2016, respectively Off-market Lease, Unfavorable Obligations under capital lease Capital Lease Obligations, Noncurrent Liabilities held for sale, less accumulated amortization of $1,239, as of December 31, 2016 Disposal Group, Including Discontinued Operation, Liabilities Total liabilities Liabilities Commitments and Contingencies (Note 7) Commitments and Contingencies Equity: Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract] Common stock, $0.01 par value, 225,000,000 shares authorized, 121,235,494 and 122,184,193 shares issued and outstanding, as of June 30, 2017 and December 31, 2016, 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 Cumulative other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Term Loans Notes Payable to Banks [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] $150 Million Term Loan $150 Million Term Loan, Maturity July 2022 [Member] $150 Million Term Loan, Maturity July 2022 [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Lines of credit and notes payable, net Revenues: Revenues [Abstract] Rental income Operating Leases, Income Statement, Lease Revenue Tenant reimbursements Tenant Reimbursements Hotel income Revenue from Owned Hotels Other property income Other Real Estate Revenue Revenues Expenses: Operating Expenses [Abstract] Property operating costs Direct Costs of Leased and Rented Property or Equipment Hotel operating costs Direct Costs of Hotels Asset and property management fees: Construction and Development Costs [Abstract] Related-party Asset And Property Management Fees Related Party The aggregate costs related to asset and property management during the reporting period paid to a related party. Other Owned Property Management Costs 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 for continuing operations. Includes production and non-production related depreciation. Costs and 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 Interest and Other Income Loss on early extinguishment of debt Gain (Loss) on Extinguishment of Debt Nonoperating income (expense) Nonoperating Income (Expense) Income before income taxes, unconsolidated joint ventures, and sales of real estate: Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax benefit (expense) Income from subsidiaries Income (Loss) from Subsidiaries, Net of Tax Income (loss) from unconsolidated entities Income (Loss) from Equity Method Investments Loss from unconsolidated joint venture Income before sales of real estate: Income (Loss) from Continuing Operations Before Gain or Loss on Sale of Properties This element is for Real Estate Investment Trust (REIT) statement of income purposes. It represents the income or loss from continuing operations Gains on sales of real estate assets Net income Statement of Comprehensive Income [Abstract] Condensed Consolidating Balance Sheets Condensed Balance Sheet [Table Text Block] Consolidating Statements of Operations Condensed Income Statement [Table Text Block] Consolidating Statements of Comprehensive Income Comprehensive Income (Loss) [Table Text Block] Consolidating Statements of Cash Flows Condensed Cash Flow Statement [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Additional Paid-In Capital Additional Paid-in Capital [Member] Cumulative Distributions in Excess of Earnings Accumulated Distributions in Excess of Net Income [Member] Cumulative Other Comprehensive Loss AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance, shares Common Stock, Shares, Outstanding Beginning balance, value Repurchases of common stock, shares Stock Repurchased and Retired During Period, Shares Repurchases of common stock Stock Repurchased and Retired During Period, Value Common stock issued to employees and directors, and amortized (net of income tax withholdings), shares Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Common stock issued to employees and directors, and amortized (net of income tax withholdings) Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Distributions to common stockholders ($0.40 in 2017 and $0.60 in 2016) Dividends Ending balance, shares Ending balance, value Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Bonds Payable Unsecured Debt [Member] Building and improvements, accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Intangible lease assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Real estate assets held for sale, accumulated amortization Real Estate Held-for-sale, Accumulated Amortization Real Estate Held-for-sale, Accumulated Amortization Allowance for doubtful accounts Allowance for Doubtful Accounts Receivable Intangible lease origination costs, accumulated amortization Finite Lived Intangible Assets, Acquired in Place leases, Accumulated Amortization The accumulated amount of amortization of finite-lived intangible assets for acquired in-place leases. Deferred lease costs, accumulated amortization Deferred Costs, Leasing, Accumulated Amortization Other assets held for sale, accumulated amortization Disposal Group, Including Discontinued Operation, Other Assets, Accumulated Amortization and Depreciation Disposal Group, Including Discontinued Operation, Other Assets, Accumulated Amortization and Depreciation Deferred financing costs, net Debt Issuance Costs, Net Bonds payable discount Debt Instrument, Unamortized Discount Intangible lease liabilities, accumulated amortization Off market lease, unfavorable, Accumulated Amortization The accumulated amount of amortization of off-market leases, unfavorable. Liabilities held for sale, accumulated amortization Disposal Group, Including Discontinued Operation, Liabilities, Accumulated Amortization Disposal Group, Including Discontinued Operation, Liabilities, Accumulated Amortization Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Basis of Presentation Consolidation, Policy [Policy Text Block] Fair Value Measurements Fair Value of Financial Instruments, Policy [Policy Text Block] Real Estate Assets Property, Plant and Equipment, Policy [Policy Text Block] Evaluating the Recoverability of Real Estate Assets Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy [Policy Text Block] Assets Held for Sale Real Estate Held for Development and Sale, Policy [Policy Text Block] Intangible Assets and Liabilities Arising from In-Place Leases where Columbia Property Trust Is the Lessor Lessor, Leases [Policy Text Block] Intangible Assets and Liabilities Arising from In-Place Leases where Columbia Property Trust Is the Lessee Lessee, Leases [Policy Text Block] Interest Rate Swap Agreements Derivatives, Policy [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Supplemental Cash Flow Elements [Abstract] Significant Noncash Investing and Financing Activities Schedule of Other Significant Noncash Transactions [Table Text Block] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] 5 Houston Center, Energy Center I, 515 Post Oak, Key Center Tower and Key Center Marriott Five Houston Center, Energy Center I, 515 Post Oak, Key Center Tower and Key Center Marriott [Member] Five Houston Center, Energy Center I, 515 Post Oak, Key Center Tower and Key Center Marriott [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Held-for-Sale Disposal Group, Held-for-sale, Not Discontinued Operations [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: Disposal Group, Including Discontinued Operation, Unclassified Balance Sheet Disclosures [Abstract] Real estate assets, at cost: Disposal Group, Including Discontinued Operation, Assets [Abstract] Land Disposal Group, Including Discontinued Operation, Land Disposal Group, Including Discontinued Operation, Land Buildings and improvements, less accumulated depreciation of $152,246 Disposal Group, Including Discontinued Operation, Buildings and Improvements Disposal Group, Including Discontinued Operation, Buildings and Improvements Intangible lease assets, less accumulated amortization of $28,545 Disposal Group, Including Discontinued Operation, Intangible Assets Construction in progress Disposal Group, Including Discontinued Operation, Construction in Progress Disposal Group, Including Discontinued Operation, Construction in Progress Total real estate assets held for sale, net Disposal Group, Including Discontinued Operation, Real Estate Assets Disposal Group, Including Discontinued Operation, Real Estate Assets Other assets held for sale: Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract] Tenant receivables, net of allowance for doubtful accounts Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net Straight-line rent receivable Disposal Group, Including Discontinued Operation, Rent Receivable Disposal Group, Including Discontinued Operation, Rent Receivable Prepaid expenses and other assets Disposal Group, Including Discontinued Operation, Prepaid and Other Assets Intangible lease origination costs, less accumulated amortization of $22,949 Disposal Group, Including Discontinued Operation, Intangible Lease Origination Costs Disposal Group, Including Discontinued Operation, Intangible Lease Origination Costs Deferred lease costs, less accumulated amortization of $11,203 Disposal Group, Including Discontinued Operation, Deferred Lease Costs Disposal Group, Including Discontinued Operation, Deferred Lease Costs Total other assets held for sale, net Liabilities held for sale: Disposal Group, Including Discontinued Operation, Liabilities [Abstract] Accounts payable, accrued expenses, and accrued capital expenditures Disposal Group, Including Discontinued Operation, Accounts Payable and Accrued Liabilities Deferred income Disposal Group, Including Discontinued Operation, Deferred Revenue Intangible lease liabilities, less accumulated amortization of $1,239 Disposal Group, Including Discontinued Operation, Intangible Lease Liability Disposal Group, Including Discontinued Operation, Intangible Lease Liability Total liabilities held for sale, net Buildings and improvements, accumulated depreciation Disposal Group, Including Discontinued Operation, Buildings and Improvements, Accumulated Depreciation Disposal Group, Including Discontinued Operation, Buildings and Improvements, Accumulated Depreciation Intangible lease assets, accumulated amortization Disposal Group, Including Discontinued Operation, Intangible Lease Assets, Accumulated Amortization Disposal Group, Including Discontinued Operation, Intangible Lease Assets, Accumulated Amortization Intangible lease origination costs, accumulated amortization Disposal Group, Including Discontinued Operation, Intangible Lease Origination Costs, Accumulated Amortization Disposal Group, Including Discontinued Operation, Intangible Lease Origination Costs, Accumulated Amortization 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 Intangible lease liabilities, accumulated amortization Disposal Group, Including Discontinued Operation, Intangible Lease Liabilities, Accumulated Amortization Disposal Group, Including Discontinued Operation, Intangible Lease Liabilities, Accumulated Amortization Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] San Francisco Joint Ventures San Francisco Joint Ventures [Member] San Francisco Joint Ventures [Member] 114 Fifth Avenue Joint Venture One Fourteen Fifth Avenue Joint Venture [Member] One Fourteen Fifth Avenue Joint Venture [Member] Related Party Transaction [Axis] Related Party Transaction [Axis] Related Party Transaction [Domain] Related Party Transaction [Domain] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Allianz Allianz [Member] Allianz [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Office Building Office Building [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] Number of real estate properties Number of Real Estate Properties Square feet of real estate Area of Real Estate Property Percent of leased office space of owned properties Leased Office Space of Owned Properties, Percent Leased Office Space of Owned Properties, Percent Number of real estate properties transferred to joint venture Number of Real Estate Properties Transferred to Joint Venture Number of Real Estate Properties Transferred to Joint Venture Real Estate [Abstract] Schedule of Properties Sold Disposal Groups, Including Discontinued Operations [Table Text Block] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecast Scenario, Forecast [Member] Allianz and Columbia Property Trust Allianz and Columbia Property Trust [Member] Allianz and Columbia Property Trust [Member] L & L Holding Company L & L Holding Company [Member] L & L Holding Company [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Proceeds from sale of ownership in joint venture Proceeds from Divestiture of Interest in Joint Venture Required amount of assets to be invested in less than one year to acquire additional interest in joint venture Equity Method Investment, Required Amount of Assets to be Invested in Less Than One Year to Acquire Additional Interest in Joint Venture Equity Method Investment, Required Amount of Assets to be Invested in Less Than One Year to Acquire Additional Interest in Joint Venture Additional ownership percentage acquired Equity Method Investment, Additional Ownership Percentage to be Acquired if Assets Investment Requirement is Met Equity Method Investment, Additional Ownership Percentage to be Acquired if Assets Investment Requirement is Met Payments to acquire interest in joint venture Payments to Acquire Interest in Joint Venture Percentage of property leased Lessor, Operating Lease, Percent Leased Lessor, Operating Lease, Percent Leased Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] 149 Madison Avenue One Forty Nine Madison Avenue [Member] One Forty Nine Madison Avenue [Member] Disposed of by Sale Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Key Center Tower & Marriott Key Center Tower and Key Center Marriot [Member] Key Center Tower and Key Center Marriot [Member] Houston Properties Sale Houston Properties [Member] Houston Properties [Member] SanTan Corporate Center Santan Corporate Center [Member] Santan Corporate Center [Member] Sterling Commerce Sterling Commerce Property [Member] Sterling Commerce Property [Member] 9127 South Jamaica Street Ninety One Twenty Seven South Jamaica Street [Member] Ninety One Twenty Seven South Jamaica Street [Member] 80 Park Plaza Eighty Park Plaza Building [Member] Eighty Park Plaza Building [Member] 9189, 9191 & 9193 South Jamaica Street South Jamaica Street [Member] South Jamaica Street [Member] 800 North Fredrick Eight Hundred North Fredrick [Member] Eight Hundred North Fredrick [Member] 100 East Pratt One Hundred East Pratt Building [Member] One Hundred East Pratt Building [Member] Purchase Price Disposal Group, Including Discontinued Operation, Consideration Gain (Loss) on Sale Gains (Losses) on Sales of Investment Real Estate Gross proceeds from sale of real estate Proceeds from Sale of Real Estate Held-for-investment, Gross Proceeds from Sale of Real Estate Held-for-investment, Gross Accruing note receivable as a result of the disposal Disposal Group, Including Discontinued Operation, Consideration, Note Receivable Disposal Group, Including Discontinued Operation, Consideration, Note Receivable Term of accruing note receivable as a result of the disposal Disposal Group, Including Discontinued Operation, Consideration, Note Receivable, Term Disposal Group, Including Discontinued Operation, Consideration, Note Receivable, Term Deferred gain on disposal Disposal Group, Deferred Gain on Disposal Gain on sale Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Income (loss) from disposal group Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Ernest money paid Payments for Deposits on Real Estate Acquisitions Square feet of office space Buildings and improvements, net Intangible lease assets, net Construction in progress Real estate assets held for sale, net Investment in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Tenant receivables, net of allowance Intangible lease origination costs, net Deferred lease costs, net Other assets held for sale Bonds payable, net Due to affiliates Due to Related Parties Intangible lease liabilities, net Liabilities held for sale Total equity Investments in real estate funded with other assets Noncash or Part Noncash Acquisition, Investments Acquired Deposits applied to sales of real estate Escrow Deposits Related to Property Sales Amortization of net discounts on debt Amortization of Debt Discount (Premium) Market value adjustments to interest rate swaps that qualify for hedge accounting treatment Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Accrued capital expenditures and deferred lease costs Other Significant Noncash Transactions, Capital Expenditures Incurred but Not yet Paid and Deferred Leasing Costs, Noncash Other Significant Noncash Transactions, Capital Expenditures Incurred but Not yet Paid and Deferred Leasing Costs, Noncash Common stock issued to employees and directors, and amortized (net of income tax withholdings) Common Stock Issued, Value, Net of Shares for Tax Withholdings Common Stock Issued, Value, Net of Shares for Tax Withholdings Total assets Equity Method Investment, Summarized Financial Information, Assets Total debt Equity Method Investment, Summarized Financial Information, Liabilities Total equity Equity Method Investment Summarized Financial Information, Equity Columbia Property Trust's investment Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table] Mortgage Notes Mortgages [Member] Credit Facilities Line of Credit [Member] $300 Million Term Loan $300 Million Term Loan, Maturity July 2020 [Member] $300 Million Term Loan, Maturity July 2020 [Member] 650 California Street building mortgage note 650 California Street Building Mortgage Note [Member] 650 California Street Building Mortgage Note [Member] 263 Shuman Boulevard building mortgage note Two-Hundred Sixty-Three Shuman Boulevard Mortgage Note [Member] Two-Hundred Sixty-Three Shuman Boulevard Mortgage Note [Member] One Glenlake building mortgage note One Glenlake Building Mortgage Note [Member] One Glenlake Building Mortgage Note [Member] 221 Main Street Building mortgage note 221 Main Street Building Mortgage Note [Member] 221 Main Street Building Mortgage Note [Member] Revolving Credit Facility JPMorgan Chase Credit Facility [Member] JPMorgan Chase Credit Facility [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Less: Deferred financing costs related to term loans and notes payable, net of accumulated amortization Face amount of issued debt instrument Debt Instrument, Face Amount Segment Information Segment Reporting Disclosure [Text Block] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Loans Payable Loans Payable [Member] Mortgages Estimated fair value of line of credit and notes payable Debt Instrument, Fair Value Disclosure Carrying value of the line of credit and notes payable Loans Payable Excluding Deferred Financing Costs Loans Payable Excluding Deferred Financing Costs Interest payments Interest Paid Interest capitalized Interest Costs Capitalized Repayment of debt Repayments of Debt Loss on early extinguishment of debt Effective interest rate Debt Instrument, Interest Rate, Effective Percentage Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Gross Intangible In-Place Lease Assets and Liabilities [Abstract] Gross Intangible In-Place Lease Assets and Liabilities [Abstract] Gross Intangible In-Place Lease Assets and Liabilities [Abstract] Intangible Lease Assets, Gross Intangible Lease Assets, Accumulated Amortization Intangible Lease Origination Costs, Gross Finite-Lived Intangible Asset, Acquired-in-Place Leases, Gross Finite-Lived Intangible Asset, Acquired-in-Place Leases, Gross Intangible Lease Origination Costs, Accumulated Amortization Below Market Lease, Gross Below Market Lease, Gross Below Market Lease, Accumulated Amortization Below Market Lease, Accumulated Amortization Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Previously granted LTIP awards, unvested Future LTIP awards 2015 Long Term Incentive Plan [Member] 2015 Long Term Incentive Plan [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Distributions paid on unvested shares Preferred Stock Dividends and Other Adjustments Net income used to calculate basic and diluted earnings per share Net Income (Loss) Available to Common Stockholders, Basic Weighted-average common shares – basic Weighted Average Number of Shares Outstanding, Basic Plus incremental weighted-average shares from time-vested conversions, less assumed share repurchases Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted-average common shares – diluted Weighted Average Number of Shares Outstanding, Diluted 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 Bonds Payable Bond Disclosure [Text Block] The entire disclosure for information about bonds, including repayment terms, interest rates, collateral provided, whether or not in compliance with covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with covenants. [Text Block] Summary of the Activity of Employee Stock Grants Schedule of Nonvested Share Activity [Table Text Block] Summary of Shares Granted to Independent Directors Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Schedule of Stock-based Compensation Expense Incurred Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest 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] Straight-line rental income Straight Line Rent Amortization Noncash interest expense Noncash interest expense The component of interest expense representing interest paid other than in cash for example by increasing the balance of debt securities and the noncash expenses charged against earnings in the period to amortize debt discount and premium associated with the related debt instruments. Loss from unconsolidated joint venture (Gain) loss on sales of real estate assets Gain (Loss) on Sale of Properties Stock-based compensation expense Share-based Compensation Changes in assets and liabilities, net of acquisitions and dispositions: Changes in assets and liabilities, net of acquisitions [Abstract] Changes in assets and liabilities, net of acquisitions [Abstract] Decrease in tenant receivables, net Increase (Decrease) in Accounts Receivable 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] Net proceeds from the sales of real estate Proceeds from Sale of Real Estate Held-for-investment Prepaid earnest money and transaction costs Capital improvements Payments to Acquire and Develop Real Estate Deferred lease costs paid Increase (Decrease) in Lease Acquisition Costs Investments in unconsolidated joint venture Net cash provided by investing activities Net Cash Provided by (Used in) Investing Activities Cash Flows from Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Financing costs paid Payments of Financing Costs Proceeds from lines of credit and notes payable Proceeds from Notes Payable Repayments of lines of credit and notes payable Repayments of Notes Payable Distributions paid to stockholders Payments of Dividends Redemptions of common stock Payments for Repurchase of Common Stock 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), Excluding Exchange Rate Effect Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Earnings Per Share Earnings Per Share [Text Block] Distributions to common stockholders per share (dollars per share) Common Stock, Dividends, Per Share, Cash Paid Line of Credit and Notes Payable Debt Disclosure [Text Block] 2026 Bonds Payable Two-Thousand and Twenty-Six Bonds Payable [Member] Two-Thousand and Twenty-Six Bonds Payable [Member] 2018 Bonds Payable Two-Thousand and Eighteen Bonds Payable [Member] Two-Thousand and Eighteen Bonds Payable [Member] 2025 Bonds Payable Two-Thousand and Twenty-Five Bonds Payable [Member] Two-Thousand and Twenty-Five Bonds Payable 2026 and 2025 Bonds Payable Two-Thousand and Twenty-Six and Two-Thousand and Twenty-Five Bonds Payable [Member] Two-Thousand and Twenty-Six and Two-Thousand and Twenty-Five Bonds Payable [Member] 2025 and 2018 Bonds Payable 2025 and 2018 Bonds Payable [Member] 2025 and 2018 Bonds Payable [Member] 2026, 2025 and 2018 Bonds Payable Two-Thousand and Twenty-Six, Two-Thousand and Twenty-Five and Two-Thousand and Eighteen Bonds Payable [Member] Two-Thousand and Twenty-Six, Two-Thousand and Twenty-Five and Two-Thousand and Eighteen Bonds Payable [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 2 Fair Value, Inputs, Level 2 [Member] Maturity of debt instrument Debt Instrument, Term Interest rate for debt instrument (percent) Debt Instrument, Interest Rate, Stated Percentage Discount rate of face value of issued debt instrument (percent) Debt Instrument, Discount Rate at Issuance of Face Value Debt Instrument, Discount Rate at Issuance of Face Value Proceeds from issuance of bonds payable Proceeds from Issuance of Long-term Debt Initial issuance discount of bonds payable Estimated fair value of debt instrument Financial Information for Parent Guarantor, Issuer Subsidiary and Non-Guarantor Subsidiaries Financial Information For Parent Issuer Guarantor Subsidiaries And Nonguarantor Subsidiaries [Text Block] Financial information for parent, issuer, guarantor subsidiaries, and nonguarantor subsidiaries. [Text Block] Intangible below market ground lease assets Amortization of Intangible Lease Assets Amortization Intangible Below-Market In-Place Lease Liabilities Amortization of Below Market Lease Schedule of Estimated Useful Lives for Real Estate Assets Schedule of Estimated Useful Lives for Real Estate Assets [Table Text Block] Schedule of Estimated Useful Lives for Real Estate Assets [Table Text Block] Schedule of Major Assets and Liabilities Classified as Held for Sale Schedule of Intangible Assets and Liabilities Schedule of Intangible Assets and Liabilities [Table Text Block] Schedule of Intangible Assets and Liabilities [Table Text Block] Schedule of Future Amortization Expense for Remaining Net Below-Market Lease Assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Interest Rate Swaps Schedule of Interest Rate Derivatives [Table Text Block] Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block] Subsequent Event Subsequent Events [Text Block] Ownership percentage of wholly owned subsidiary Ownership Percentage, Wholly Owned Subsidiary Ownership Percentage, Wholly Owned Subsidiary Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Schedule of Error Corrections and Prior Period Adjustment Restatement [Table] Adjustments for Error Corrections [Axis] Adjustments for Error Corrections [Axis] Adjustments for Error Correction [Domain] Adjustments for Error Correction [Domain] Intercompany Cash Transfers Between Parent and Subsidiaries Broken Out by Cash Flow Type Intercompany Cash Transfers Between Parent and Subsidiaries Broken Out by Cash Flow Type [Member] Intercompany Cash Transfers Between Parent and Subsidiaries Are Now Broken Out by Cash Flow Type [Member] Restatement Adjustment Restatement Adjustment [Member] Parent Issuer Condensed Financial Statements, Captions [Line Items] Error Corrections and Prior Period Adjustments Restatement [Line Items] Increase in operating cash flows Increase (decrease) in investing cash flows Increase (decrease) in financing cash flows Supplemental Disclosures of Noncash Investing and Financing Activities Cash Flow, Supplemental Disclosures [Text Block] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Employees Employees [Member] Employees [Member] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Future employee awards Deferred Compensation Arrangement with Individual, Compensation Expense Schedule of Basic and Diluted Earnings Per Share Computations Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Other Income Other Income [Member] Blackstone Property Partners Blackstone Property Partners [Member] Blackstone Property Partners [Member] Market Square East & West LLC Market Square East & West LLC [Member] Market Square East & West LLC [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Washington, D.C. DISTRICT OF COLUMBIA Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Prepaid Expenses and Other Assets Prepaid Expenses and Other Assets [Member] Prepaid Expenses and Other Assets [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Number of office buildings Mortgage note transferred to joint venture Real Estate Investments, Joint Ventures, Debt Real Estate Investments, Joint Ventures, Debt Mortgage note interest rate Guaranty liability Guaranty Liabilities Monthly property management fee earned (percent) Property Management Fee, Percent Fee Asset management fee earned annually Asset Management Fee Annual Revenue Asset Management Fee Annual Revenue Property Management Fee Revenue Property Management Fee Revenue Property management fees due to Company Property Management Fee Receivable Property Management Fee Receivable Unconsolidated Joint Venture Equity Method Investments and Joint Ventures Disclosure [Text Block] Shares Rollforward Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Unvested shares - beginning of period (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Vested (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Unvested shares - end of period (shares) Weighted-Average, Grant-Date Fair Value Rollforward Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Unvested shares - beginning of period (dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (dollars per share) Vested (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 Forfeited (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 shares - end of period (dollars per share) Shares expected to ultimately vest Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Expected to Vest Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Expected to Vest Expected forfeiture rate Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Expected Forfeiture Rate Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Expected Forfeiture Rate Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Eliminations Cash flows from operating activities Cash flows from investing activities: Investment in real estate and related assets Payments to Acquire and Develop Real Estate and Lease Acquisition Costs Payments to Acquire and Develop Real Estate and Lease Acquisition Costs Distributions from subsidiaries Payments for (Proceeds from) Businesses and Interest in Affiliates Cash flows from financing activities: Borrowings, net of fees Proceeds from Notes Payable, Net of Financing Costs Proceeds from Notes Payable, Net of Financing Costs Repayments Repayments of Long-term Debt Distributions Distributions Paid to Stockholders for Dividends and Reinvested Shares of Common Stock Distributions Paid to Stockholders for Dividends and Reinvested Shares of Common Stock Repurchases of common stock Increase (decrease) in net proceeds from sales of real estate Increase (Decrease) of Proceeds from Sale of Real Estate Held-for-investment Increase (Decrease) of Proceeds from Sale of Real Estate Held-for-investment Increase (decrease) in distributions from subsidiaries Increase (Decrease) in Proceeds from Businesses and Interest in Affiliates Increase (Decrease) in Proceeds from Businesses and Interest in Affiliates Increase (decrease) in distributions Increase (Decrease) of Distributions Paid to Stockholders for Dividends and Reinvested Shares of Common Stock Increase (Decrease) of Distributions Paid to Stockholders for Dividends and Reinvested Shares of Common Stock Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest rate contracts Interest Rate Contract [Member] Accounts payable Accounts Payable [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivatives designated as hedging instruments: Derivative Instruments in Hedges, at Fair Value, Net [Abstract] Interest rate contracts Derivative Instruments in Hedges, at Fair Value, Net Summary of Derivative Instruments Impact on Results of Operations [Abstract] Summary of Derivative Instruments Impact on Results of Operations [Abstract] Market value adjustment to interest rate swaps designated as hedging instruments and included in other comprehensive income Real Estate Transactions Real Estate Disclosure [Text Block] Schedule of Line of Credit and Notes Payable Indebtedness Schedule of Debt [Table Text Block] Income Statement [Abstract] Asset and property management fees Amortization Interest expense Gain (loss) on sales of real estate assets Per-share information – basic: Earnings Per Share, Basic [Abstract] Net income (dollars per share) Earnings Per Share, Basic Weighted-average common shares outstanding – basic Per-share information – diluted: Earnings Per Share, Diluted [Abstract] Net income (dollars per share) Earnings Per Share, Diluted Weighted-average common shares outstanding – diluted Dividends per share (dollars per share)