Real Estate [Abstract] Rental Property Real Estate Disclosure [Text Block] Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] New Accounting Pronouncements and Changes in Accounting Principles [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Increase to cumulative dividends in excess of earnings due to new accounting principle in period of adoption Cumulative Effect of New Accounting Principle in Period of Adoption Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Operating lease liabilities Operating Lease, Liability Commitments and Contingencies Disclosure [Abstract] Letters of credit outstanding Letters of Credit Outstanding, Amount Contractual Obligation Contractual Obligation Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group, Disposed of by Sale, Not Discontinued Operations Disposal Group, Disposed of by 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] Number of buildings disposed Number of Real Estate Properties Area (in square feet) Area of Real Estate Property Carrying value of property sold Real Estate Investment Property, Net Contribution to revenue Disposal Group, Including Discontinued Operation, Revenue Disposal Group, Including Discontinued Operation, Operating Income (Loss) Disposal Group, Including Discontinued Operation, Operating Income (Loss) Net proceeds from sales of rental property Proceeds from Sale of Real Estate Held-for-investment Gain (Loss) on Sale Gains (Losses) on Sales of Investment Real Estate Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents Cash and cash equivalents and restricted cash—end of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Leases [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Accrued Income Receivable [Member] Accrued Income Receivable [Member] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Deferred Rent Receivables, Net Deferred Rent Receivables, Net Lease Security Deposits Available in Letters of Credit Lease Security Deposits Available in Letters of Credit Represents the amount of lease security deposit for the benefit of the entity, available in letters of credit. Lease security deposits in restricted cash Security Deposit Lease security deposits included in tenant prepaid rent and security deposits on the Balance Sheet Security Deposit Liability Real Estate Taxes, Tenant Responsibility Real Estate Taxes, Tenant Responsibility Real Estate Taxes, Tenant Responsibility Noncontrolling Interest [Abstract] Noncontrolling Interest [Table] Noncontrolling Interest [Table] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] LTIP Units Long Term Incentive Plan Units [Member] Represents details pertaining to long term incentive plan units. Other Common Units Other Noncontrolling Common Units [Member] Represents activity related to common units other than units issued through equity incentive plans. Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Noncontrolling Interest - Unit holders in Operating Partnership Noncontrolling Interest [Member] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Noncontrolling interest Increase (Decrease) in Partners' Capital [Roll Forward] Units outstanding, balance at beginning of period (in units) Limited Partners' Capital Account, Units Outstanding Units outstanding, balance at beginning of period (in units) Other Ownership Interests, Units Outstanding Granted/Issued Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Forfeited Stock Issued During Period, Shares, Share-based Compensation, Forfeited Conversions from LTIP units to Other Common Units Stock Issued During Period, Shares, Conversion of Units Redemptions from Other Common Units to common stock Partners' Capital Account, Units, Converted Units outstanding, balance at end of period (in units) Units outstanding, balance at end of period (in units) Noncontrolling interest ownership percentage Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Noncontrolling interest activity Noncontrolling Interest Activity [Table Text Block] Noncontrolling Interest Activity [Table Text Block] Schedule of share-based payment award, LTIP unit awards, valuation assumptions Schedule of Share-based Payment Award, LTIP Unit Awards, Valuation Assumptions [Table Text Block] Schedule of Share-based Payment Award, LTIP Unit Awards, Valuation Assumptions [Table Text Block] Schedule of activity related to unvested LTIP unit awards Schedule of Nonvested Performance-based Units Activity [Table Text Block] Schedule of vested LTIP unit award activity Schedule of Vested Performance-based Units Activity [Table Text Block] Schedule of Vested Performance-based Units Activity [Table Text Block] Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series C Preferred Stock Series C Preferred Stock [Member] Statement Statement [Line Items] Assets Assets [Abstract] Rental Property: Real Estate Investment Property, Net [Abstract] Land Land Buildings and improvements, net of accumulated depreciation of $321,010 and $316,930, respectively Investment Building and Building Improvements Deferred leasing intangibles, net of accumulated amortization of $224,740 and $246,502, respectively Intangible Assets, Net (Excluding Goodwill) Total rental property, net Tenant accounts receivable Accounts Receivable, Net Prepaid expenses and other assets Prepaid Expense and Other Assets Interest rate swaps Derivative Asset Total assets Assets Liabilities and Equity Liabilities and Equity [Abstract] Liabilities: Liabilities [Abstract] Unsecured credit facility Long-term Line of Credit Unsecured term loans, net Loans Payable Unsecured notes, net Notes Payable Mortgage notes, net Secured Debt Accounts payable, accrued expenses and other liabilities Accounts Payable and Accrued Liabilities Interest rate swaps Derivative Liability Tenant prepaid rent and security deposits Customer Advances and Deposits Dividends and distributions payable Dividends Payable Deferred leasing intangibles, net of accumulated amortization of $10,394 and $12,764, respectively Below Market Lease, Net Total liabilities Liabilities Commitments and contingencies (Note 11) Commitments and Contingencies Equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, par value $0.01 per share, 15,000,000 shares authorized, Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred stock Preferred Stock, Value, Issued Common stock, par value $0.01 per share, 150,000,000 shares authorized, 118,174,102 and 112,165,786 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Cumulative dividends in excess of earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative [Table] Derivative [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swaps Interest Rate Swap [Member] Risk Management Objective of Using Derivatives Derivative [Line Items] Cash Flow Hedges of Interest Rate Risk Interest Rate Cash Flow Hedges [Abstract] Additional amount reclassified from accumulated other comprehensive income (loss) as a decrease to interest expense over the next twelve months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Income (loss) recognized in accumulated other comprehensive income (loss) on interest rate swaps Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Income (loss) reclassified from accumulated other comprehensive income into income (loss) as interest expense Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Total interest expense presented in the Consolidated Statements of Operations in which the effects of cash flow hedges are recorded Interest Expense Assets Needed for Immediate Settlement, Aggregate Fair Value Assets Needed for Immediate Settlement, Aggregate Fair Value Credit-risk-related Contingent Features Derivative, Credit Risk Related Contingent Features [Abstract] Leases Lessor, Operating Leases [Text Block] Leases Lessee, Operating Leases [Text Block] Building and Improvements Real Estate Investment Property, Accumulated Depreciation Deferred leasing intangibles assets, accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Deferred leasing intangibles liabilities, accumulated amortization Below Market Lease, Accumulated Amortization Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized 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 Preferred stock, shares issued Preferred Stock, Shares Issued Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Preferred stock, liquidation preference (in dollars per share) Preferred Stock, Liquidation Preference Per Share Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Noncontrolling Interest Noncontrolling Interest Disclosure [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair value of the interest rate swaps outstanding Derivatives, Fair Value [Line Items] Notional amount assets Derivative Asset, Notional Amount Fair value - assets Interest Rate Derivative Assets, at Fair Value Notional amount liabilities Derivative Liability, Notional Amount Fair Value - liabilities Interest Rate Derivative Liabilities, at Fair Value Schedule of computation of basic and diluted earnings per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] 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] Common Stock Common Stock [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Independent Director Director [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted stock Restricted Stock [Member] Performance shares Performance Shares [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] General and Administrative Expenses General and Administrative Expense [Member] Equity Incentive Plan Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-based compensation Allocated Share-based Compensation Expense Number of days of average trailing stock price used to calculate number of shares of common stock granted Share-based Compensation Arrangement by Share-baed Payment Award, Equity Instruments Other Than Options, Trailing Average Common Stock Price, Period Share-based Compensation Arrangement by Share-baed Payment Award, Equity Instruments Other Than Options, Trailing Average Common Stock Price, Period Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Interest Expense [Member] Interest Expense [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Accounts Payable and Accrued Liabilities [Member] Accounts Payable and Accrued Liabilities [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Unsecured Credit Facility Line of Credit [Member] Unsecured Term Loans Long-term Debt [Member] Unsecured Notes Unsecured Debt [Member] Mortgage Loans Payable Mortgages [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument, Unused Borrowing Capacity, Amount Debt Instrument, Unused Borrowing Capacity, Amount Interest payable Interest Payable, Current Amortization of deferred financing fees Amortization of Debt Issuance Costs Line of Credit Facility, Commitment Fee Amount Line of Credit Facility, Commitment Fee Amount Net book value of properties that are collateral for debt arrangements Debt Instrument, Collateral Amount Operating Lease, Lease Income [Table Text Block] Operating Lease, Lease Income [Table Text Block] Lessor, Operating Lease, Payments to be Received, Maturity Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block] Schedule of minimum lease payments receivable Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Lease, Cost [Table Text Block] Lease, Cost [Table Text Block] Lessee, Operating Lease, Liability, Maturity [Table Text Block] Lessee, Operating Lease, Liability, Maturity [Table Text Block] Document and Entity Information Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Period End Date Document Period End Date Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Document Type Document Type Amendment Flag Amendment Flag Schedule of Finite-Lived Intangible Assets [Table] 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 leases Above Market Leases [Member] Other intangible lease assets Other Intangible Assets [Member] Net decrease to rental income related to above and below market lease amortization Above And Below Market Leases [Member] Above market lease represents leases acquired as part of a real property acquisition at above market lease rate and below market lease represents leases acquired as part of a real property acquisition at below market lease rate. Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Deferred leasing intangibles, gross Finite-Lived Intangible Assets, Gross Deferred leasing intangibles assets, accumulated amortization Deferred leasing intangibles, net Finite-Lived Intangible Assets, Net Below market lease, gross Below Market Lease, Gross Below market lease, accumulated amortization Below market lease, net Net decrease to rental income related to above and below market lease amortization Net decrease to rental income related to above and below market lease amortization Net decrease to rental income related to above and below market lease amortization Amortization expense related to other intangible lease assets Amortization of Intangible Assets Estimated Net Amortization of In-Place Leases, Leasing Commissions and Tenant Relationships Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] Remainder of 2019 Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Five Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [Abstract] Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [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] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Performance Units Granted in 2016 [Member] Performance Units Granted in 2016 [Member] Performance Units Granted in 2016 [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Vesting period (in years) Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Issuance of vested LTIP units and shares Stock Issued During Period, Shares, Share-based Compensation, Gross Stock Repurchased and Retired During Period, Shares Stock Repurchased and Retired During Period, Shares Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Unrecognized compensation costs Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Unrecognized compensation costs, period for recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Equity [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization and Description of Business Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Warehouse - Distribution buildings Warehouse [Member] Light Manufacturing buildings Industrial Property [Member] Flex/Office Buildings Office Building [Member] Real Estate Properties [Line Items] Real Estate Properties [Line Items] Ownership interest in Operating Partnership (as a percent) Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest Number of properties Number of states in which the entity owned buildings Number of States in which Entity Operates Percentage of buildings leased to tenants Occupancy Percentage of Real Estate Properties Occupancy Percentage of Real Estate Properties Number of tenants Number of Tenants Represents the number of tenants. Use of Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Debt Long-term Debt [Text Block] Schedule of Derivative Instruments [Table Text Block] Schedule of Derivative Instruments [Table Text Block] Schedule of interest rate swaps Schedule of Interest Rate Derivatives [Table Text Block] Schedule of the location in the financial statements of the gain or loss recognized on interest rate swaps Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Schedule of financial instruments accounted for at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Interest Rate Derivative, Regions Bank, March 01, 2013 Interest Rate Derivative, Regions Bank, March 01, 2013 [Member] Interest Rate Derivative, Regions Bank, March 01, 2013 [Member] Interest Rate Derivative, Capital One, July 01, 2013 Interest Rate Derivative, Capital One, July 01, 2013 [Member] Interest Rate Derivative, Capital One, July 01, 2013 [Member] Interest Rate Derivative, Capital One, August 01, 2013 Interest Rate Derivative, Capital One, August 01, 2013 [Member] Interest Rate Derivative, Capital One, August 01, 2013 [Member] Interest Rate Derivative, Regions Bank, February 03, 2014 Interest Rate Derivative, Regions Bank, February 03, 2014 [Member] Interest Rate Derivative, Regions Bank, February 03, 2014 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, September 29, 2016 Interest Rate Derivative, The Toronto-Dominion Bank, September 29, 2016 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, September 29, 2016 [Member] Interest Rate Derivative, PNC Bank, September 29, 2016 Interest Rate Derivative, PNC Bank, September 29, 2016 [Member] Interest Rate Derivative, PNC Bank, September 29, 2016 [Member] Interest Rate Derivative, Regions Bank, September 29, 2016 Interest Rate Derivative, Regions Bank, September 29, 2016 [Member] Interest Rate Derivative, Regions Bank, September 29, 2016 [Member] Interest Rate Derivative, US Bank, September 29, 2016 Interest Rate Derivative, US Bank, September 29, 2016 [Member] Interest Rate Derivative, US Bank, September 29, 2016 [Member] Interest Rate Derivative, Capital One, September 29, 2016 Interest Rate Derivative, Capital One, September 29, 2016 [Member] Interest Rate Derivative, Capital One, September 29, 2016 [Member] Interest Rate Derivative, Royal Bank of Canada, March 20, 2015 Interest Rate Derivative, Royal Bank of Canada, March 20, 2015 [Member] Interest Rate Derivative, Royal Bank of Canada, March 20, 2015 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, March 20, 2015 Interest Rate Derivative, The Toronto-Dominion Bank, March 20, 2015 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, March 20, 2015 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, September 10, 2017 Interest Rate Derivative, The Toronto-Dominion Bank, September 10, 2017 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, September 10, 2017 [Member] Interest Rate Derivative, Wells Fargo Bank, March 20, 2015 Interest Rate Derivative, Wells Fargo Bank, March 20, 2015 [Member] Interest Rate Derivative, Wells Fargo Bank, March 20, 2015 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, February 14, 2020 Interest Rate Derivative, The Toronto-Dominion Bank, February 14, 2020 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, February 14, 2020 [Member] Interest Rate Derivative, Regions Bank, February 14, 2020 Interest Rate Derivative, Regions Bank, February 14, 2020 [Member] Interest Rate Derivative, Regions Bank, February 14, 2020 [Member] Interest Rate Derivative, Capital One, February 14, 2020 Interest Rate Derivative, Capital One, February 14, 2020 [Member] Interest Rate Derivative, Capital One, February 14, 2020 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, October 30, 2017 Interest Rate Derivative, The Toronto-Dominion Bank, October 30, 2017 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, October 30, 2017 [Member] Interest Rate Derivative, Royal Bank of Canada, October 30, 2017 Interest Rate Derivative, Royal Bank of Canada, October 30, 2017 [Member] Interest Rate Derivative, Royal Bank of Canada, October 30, 2017 [Member] Interest Rate Derivative, Wells Fargo Bank, October 30, 2017 Interest Rate Derivative, Wells Fargo Bank, October 30, 2017 [Member] Interest Rate Derivative, Wells Fargo Bank, October 30, 2017 [Member] Interest Rate Derivative, PNC Bank, $25m, October 30, 2017 Interest Rate Derivative, PNC Bank, $25m, October 30, 2017 [Member] Interest Rate Derivative, PNC Bank, $25m, October 30, 2017 [Member] Interest Rate Derivative, PNC Bank, $50m, October 30, 2017 Interest Rate Derivative, PNC Bank, $50m, October 30, 2017 [Member] Interest Rate Derivative, PNC Bank, $50m, October 30, 2017 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, July 26, 2019 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, July 26, 2019 [Member] Interest Rate Derivative, The Toronto-Dominion Bank, July 26, 2019 [Member] Interest Rate Derivative, PNC Bank, July 26, 2019 [Member] Interest Rate Derivative, PNC Bank, July 26, 2019 [Member] Interest Rate Derivative, PNC Bank, July 26, 2019 [Member] Interest Rate Derivative, Bank of Montreal, July 26, 2019 [Member] Interest Rate Derivative, Bank of Montreal, July 26, 2019 [Member] Interest Rate Derivative, Bank of Montreal, July 26, 2019 [Member] Interest Rate Derivative, US Bank, July 26, 2019 [Member] Interest Rate Derivative, US Bank, July 26, 2019 [Member] Interest Rate Derivative, US Bank, July 26, 2019 [Member] Unsecured Term Loan Swaps Derivative Instrument Detail [Abstract] Derivative Asset, Fair Value, Gross Asset Derivative Asset, Fair Value, Gross Asset Derivative Liability, Fair Value, Gross Liability Derivative Liability, Fair Value, Gross Liability Fixed Interest Rate (as a percent) Derivative, Fixed Interest Rate 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 Adjustment to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Loss on impairments Asset Impairment Charges Non-cash portion of interest expense Paid-in-Kind Interest Amortization of above and below market leases, net Amortization of above and below Market Leases Straight-line rent adjustments, net Straight Line Rent Dividends on forfeited equity compensation Restricted Stock Award, Forfeitures, Dividends Gain on the sales of rental property, net Gain (Loss) on Disposition of Property Plant Equipment Non-cash compensation expense Share-based Compensation Change in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Tenant accounts receivable Increase (Decrease) in Accounts Receivable Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable, accrued expenses and other liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Tenant prepaid rent and security deposits Increase (Decrease) in Customer Advances and Deposits Total adjustments Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities 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] Acquisitions of land and buildings and improvements Payments to Acquire Commercial Real Estate Additions of land and building and improvements Payments for Capital Improvements Acquisitions of other assets Payments to Acquire Other Receivables Proceeds from sales of rental property, net Proceeds from Sale of Buildings Acquisition deposits, net Payments for (Proceeds from) Deposits on Real Estate Acquisitions Acquisitions of deferred leasing intangibles Payments to Acquire Intangible Assets 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] Proceeds from unsecured credit facility Proceeds from Unsecured Lines of Credit Repayment of unsecured credit facility Repayments of Lines of Credit Proceeds from unsecured term loans Proceeds from Issuance of Other Long-term Debt Repayment of mortgage notes Repayments of Secured Debt Payment of loan fees and costs Payments of Financing Costs Dividends and distributions Payments of Dividends Proceeds from sales of common stock Proceeds from Issuance of Common Stock Dividends and distributions Payments Related to Tax Withholding for Share-based Compensation Offering costs Payments of Stock Issuance Costs Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Decrease in cash and cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents and restricted cash—beginning of period Cash and cash equivalents and restricted cash—end of period Supplemental disclosure: Supplemental Cash Flow Information [Abstract] Cash paid for interest, net of capitalized interest Interest Paid, Excluding Capitalized Interest, Operating Activities Supplemental schedule of non-cash investing and financing activities Noncash Investing and Financing Items [Abstract] Change in additions of land, building, and improvements included in accounts payable, accrued expenses, and other liabilities Capital Expenditures Incurred but Not yet Paid Additions to building and other capital improvements from non-cash compensation Capital Expenditures Incurred Through Issuance of Non-Cash Compensation Capital Expenditures Incurred Through Issuance of Non-Cash Compensation Change in loan fees, costs, and offering costs included in accounts payable, accrued expenses, and other liabilities Debt Issuance Costs Incurred During Noncash or Partial Noncash Transaction Leases cumulative effect adjustment Leases cumulative effect adjustment Leases cumulative effect adjustment Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Unvested at beginning of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Vested (in units) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in units) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Unvested at end of period (in shares) Vested (in units) Fair value of units vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Participating securities Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Preferred Stock Preferred Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Cumulative Dividends in excess of Earnings Accumulated Distributions in Excess of Net Income [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Total Stockholders' Equity Parent [Member] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Balance (in shares) Shares, Outstanding Cumulative effect on retained earnings Cumulative Effect on Retained Earnings, Net of Tax Proceeds from sales of common stock Stock Issued During Period, Value, New Issues Proceeds from sales of common stock (in shares) Stock Issued During Period, Shares, New Issues Offering costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Dividends, Common Stock Dividends, Common Stock Dividends Dividends Dividends and Distributions, Net Dividends and Distributions, Net Dividends and Distributions, Net Distribution Made to Limited Partner, Cash Distributions Declared Distribution Made to Limited Partner, Cash Distributions Declared Non-cash compensation activity, net Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Non-cash compensation activity (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Non-cash compensation activity (in excess of earnings) Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Redemption of common units to common stock Stock Issued During Period, Value, Conversion of Units Redemption of common units to common stock (in shares) Rebalancing of noncontrolling interest Noncontrolling Interest, Increase from Subsidiary Equity Issuance Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Balance Balance (in shares) Quarterly Financial Information Quarterly Financial Information [Text Block] Basis of Presentation Consolidation, Policy [Policy Text Block] New Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Reclassification Reclassification, Policy [Policy Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Real Estate Investment Trust Taxable Real Estate Investment Trust Subsidy [Member] Taxable Real Estate Investment Trust Subsidy Business Acquisition [Line Items] Business Acquisition [Line Items] State and local income, excise and franchise taxes Current State and Local Tax Expense (Benefit) Liabilities for uncertain tax positions Liability for Uncertainty in Income Taxes, Current Summary of the mortgage notes payable, unsecured term loans and credit facility Schedule of Long-term Debt Instruments [Table Text Block] Interest Income and Interest Expense Disclosure [Table Text Block] Interest Income and Interest Expense Disclosure [Table Text Block] Schedule of aggregate carrying value of the debt and the corresponding estimate of fair value Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Stockholders' Equity Note [Abstract] Equity Stockholders' Equity Note Disclosure [Text Block] Remainder of Fiscal Year Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year 2020 Lessee, Operating Lease, Liability, Payments, Due Year Two 2021 Lessee, Operating Lease, Liability, Payments, Due Year Three 2022 Lessee, Operating Lease, Liability, Payments, Due Year Four 2023 Lessee, Operating Lease, Liability, Payments, Due Year Five Thereafter Lessee, Operating Lease, Liability, Payments, Due after Year Five Lessee, Operating Lease, Liability, Payments, Due Lessee, Operating Lease, Liability, Payments, Due Less: Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Term Loan Term Loan [Member] Term Loan [Member] $150 Million Wells Fargo Unsecured Term Loan C $150 Million Unsecured Term Loan C [Member] Details pertaining to unsecured debt C, due on March 21, 2021. $150 Million Wells Fargo Unsecured Term Loan B $150 Million Unsecured Term Loan B [Member] Details pertaining to unsecured debt B, due on March 21, 2021. $150 Million Wells Fargo Unsecured Term Loan A $150 Million Unsecured Term Loan A [Member] Details pertaining to unsecured debt A, due on March 31, 2022. $150 Million Unsecured Term Loan D [Member] $150 Million Unsecured Term Loan D [Member] Details pertaining to unsecured debt D, due on June 13, 2028 $175 Million Unsecured Term Loan E [Member] $175 Million Unsecured Term Loan E [Member] Details pertaining to unsecured debt E, due on January 15, 2024. Unsecured Notes Unsecured Notes [Member] Unsecured Notes [Member] $100 Million Series F Unsecured Notes $100 Million Series F Unsecured Notes [Member] $100 Million Series F Unsecured Notes [Member] $50 Million Series A Unsecured Notes $50 Million Series A Unsecured Notes [Member] $50 Million Series A Unsecured Notes [Member] $100 Million Series D Unsecured Notes $100 Million Series D Unsecured Notes [Member] $100 Million Series D Unsecured Notes [Member] $75 Million Series G Unsecured Notes [Member] $75 Million Series G Unsecured Notes [Member] $75 Million Series G Unsecured Notes $50 Million Series B Unsecured Notes $50 Million Series B Unsecured Notes [Member] $50 Million Series B Unsecured Notes [Member] $80 Million Series C Unsecured Notes $80 Million Series C Unsecured Notes [Member] $80 Million Series C Unsecured Notes [Member] $20 Million Series E Unsecured Notes $20 Million Series E Unsecured Notes [Member] $20 Million Series E Unsecured Notes [Member] $100 Million Series H Unsecured Notes [Member] $100 Million Series H Unsecured Notes [Member] $100 Million Series H Unsecured Notes Wells Fargo Bank, National Association CMBS Loan Wells Fargo Bank, National Association CMBS Loan [Member] Wells Fargo Bank, National Association CMBS Loan [Member] Thrivent Financial for Lutherans Due December 15, 2023 [Member] Thrivent Financial for Lutherans Due December 15, 2023 [Member] Thrivent Financial for Lutherans Due December 15, 2023 Prepaid Expenses and Other Assets Prepaid Expenses and Other Current Assets [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Long-term debt, gross Long-term Debt, Gross Unamortized debt issuance costs Debt Issuance Costs, Net Unamortized fair market value premium Debt Instrument, Unamortized Premium Principal outstanding Long-term Debt Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Debt Instrument, Basis Spread on Variable Rate Debt Instrument, Basis Spread on Variable Rate Weighted average interest rate Long-term Debt, Weighted Average Interest Rate, at Point in Time Penalty free prepayment period Debt Instrument, Prepayment Penalty, Period Without Penalty Debt Instrument, Prepayment Penalty, Period Without Penalty Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Notional amount Derivative, Notional Amount Class of Stock Disclosures [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Forecast [Member] Scenario, Forecast [Member] Class of Stock [Line Items] Class of Stock [Line Items] Common Stock, Dividends, Per Share, Cash Paid Common Stock, Dividends, Per Share, Cash Paid Common Stock, Dividends, Per Share, Declared Common Stock, Dividends, Per Share, Declared Property Subject to or Available for Operating Lease, by Major Property Class [Table] Property Subject to or Available for Operating Lease, by Major Property Class [Table] Major Property Class [Axis] Major Property Class [Axis] Major Property Class [Domain] Major Property Class [Domain] Land Land [Member] Buildings, net of accumulated depreciation of $211,755 and $199,497, respectively Building [Member] Tenant improvements, net of accumulated depreciation of $21,026 and $36,450, respectively Leasehold Improvements [Member] Building and land improvements, net of accumulated depreciation of $88,229 and $80,983, respectively Land, Buildings and Improvements [Member] Construction in progress Construction in Progress [Member] Deferred leasing intangibles, net of accumulated amortization of $224,740 and $246,502, respectively Finite-Lived Intangible Assets [Member] Property Subject to or Available for Operating Lease [Line Items] Property Subject to or Available for Operating Lease [Line Items] Rental property, net Property Subject to or Available for Operating Lease, Net Rental property, accumulated depreciation Property Subject to or Available for Operating Lease, Accumulated Depreciation Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Operating Expense [Member] Operating Expense [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Lessee, Operating Lease, Term of Contract Lessee, Operating Lease, Term of Contract Lessee, Operating Lease, Renewal Term Lessee, Operating Lease, Renewal Term Operating Lease, Weighted Average Remaining Lease Term Operating Lease, Weighted Average Remaining Lease Term Operating Lease, Weighted Average Discount Rate, Percent Operating Lease, Weighted Average Discount Rate, Percent Lease, Cost Lease, Cost Operating Lease, Payments Operating Lease, Payments Schedule of components of rental property Schedule of Property Subject to or Available for Operating Lease [Table Text Block] Schedule of real estate properties acquired Schedule of Business Acquisitions, by Acquisition [Table Text Block] Summary of allocation of the consideration paid for the acquired assets and liabilities in connection with the acquisition of buildings at the date of acquisition Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Schedule of pro forma information for acquired properties Business Acquisition, Pro Forma Information [Table Text Block] Impaired Assets to be Disposed of by Method Other than Sale [Table Text Block] Impaired Assets to be Disposed of by Method Other than Sale [Table Text Block] Schedule of Finite-Lived Intangible Assets and Below Market Leases Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of Finite-Lived Intangible Assets, Future Amortization Expense Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Below Market Lease, Future Amortization Income Below Market Lease, Future Amortization Income [Table Text Block] Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Expected dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Fair value of performance units grant (in thousands) Share-based Compensation by Share-based Payment Award, Fair Value Assumptions, Estimated Fair Value Share-based Compensation by Share-based Payment Award, Fair Value Assumptions, Estimated Fair Value Weighted Average Weighted Average [Member] Sale of Stock [Axis] Sale of Stock [Axis] Sale of Stock [Domain] Sale of Stock [Domain] At The Market Program 2019 $600 Million At The Market Program 2019 $600 Million [Member] At The Market Program 2019 $600 Million At The Market Program 2017 $500 Million At The Market Program 2017 $500 Million [Member] At The Market Program 2017 $500 Million [Member] At The Market (ATM) Program At Market Program [Member] Represents information pertaining to the "at the market" program used by the entity to raise capital. Common Stock Value Authorized under Stock Offering Program Common Stock Value Authorized under Stock Offering Program Represents the aggregate value of common stock which may be sold through sales agents under the stock offering program. Aggregate value of common stock available to be sold under the ATM Common Stock Value Available for Issuance under Stock Offering Program Represents the aggregate value of common stock available to be sold under the stock offering program. Number of shares sold Issue price (in dollars per share) Sale of Stock, Price Per Share Sales agents' fee Payments of Stock Issuance Costs, Agents' Fees Payments of Stock Issuance Costs, Agents' Fees Net proceeds Proceeds From Issuance of Common Stock, Net Proceeds From Issuance of Common Stock, Net Fixed lease payments Operating Lease, Lease Income, Lease Payments Variable lease payments Operating Lease, Variable Lease Income Straight-line rental income Straight Line Rent Adjustments Net decrease to rental income related to above and below market lease amortization Total rental income Operating Lease, Lease Income Remainder of Fiscal Year Lessor, Operating Lease, Payments to be Received, Remainder of Fiscal Year 2020 Lessor, Operating Lease, Payments to be Received, Two Years 2021 Lessor, Operating Lease, Payments to be Received, Three Years 2022 Lessor, Operating Lease, Payments to be Received, Four Years 2023 Lessor, Operating Lease, Payments to be Received, Five Years Thereafter Lessor, Operating Lease, Payments to be Received, Thereafter 2019 Operating Leases, Future Minimum Payments Receivable, Current 2020 Operating Leases, Future Minimum Payments Receivable, in Two Years 2021 Operating Leases, Future Minimum Payments Receivable, in Three Years 2022 Operating Leases, Future Minimum Payments Receivable, in Four Years 2023 Operating Leases, Future Minimum Payments Receivable, in Five Years Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Schedule of Cash, Cash Equivalents and Restricted Cash Restrictions on Cash and Cash Equivalents [Table Text Block] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Rapid City, SD, Q4 2007 Rapid City, SD, Q4 2007 [Member] Rapid City, SD, Q4 2007 [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Income Approach Valuation Technique Valuation, Income Approach [Member] Number of Buildings Impaired Number of Buildings Impaired Number of Buildings Impaired Property, Plant, and Equipment, Fair Value Disclosure Property, Plant, and Equipment, Fair Value Disclosure Impairment of Real Estate Impairment of Real Estate Fair Value Inputs, Discount Rates Fair Value Inputs, Discount Rates Fair Value Inputs, Discount Rate for Impairments. Fair Value Inputs Exit Capitalization Rate Fair Value Inputs Exit Capitalization Rate Represents the exit capitalization rate used to as an input to measure fair value. In-place leases Leases, Acquired-in-Place [Member] Tenant relationships Customer Relationships [Member] Below market leases Leases, Acquired-in-Place, Market Adjustment [Member] Business Acquisition [Line Items] Allocation of the consideration paid for the acquired assets and liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract] Land Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land Buildings Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings Tenant improvements Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Leasehold Improvements Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Leasehold Improvements Building and land improvements Business Acquisition, Purchase Price Allocation Building and Land Improvements Amount of acquisition cost of a business combination allocated to building and land improvements included in real estate. Construction in progress Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other Deferred leasing intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Total purchase price Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Before Debt Incurred Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the liabilities assumed. Excludes mortgage debt assumed in acquisition. Weighted average amortization period of lease intangibles Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Series B Preferred Stock Series B Preferred Stock [Member] Dividend rate (as a percent) Preferred Stock, Dividend Rate, Percentage Preferred Stock, Dividends Per Share, Declared Preferred Stock, Dividends Per Share, Declared Dividends Payable, Date Declared Dividends Payable, Date Declared Dividends Payable, Date to be Paid Dividends Payable, Date to be Paid Stock Redeemed or Called During Period, Shares Stock Redeemed or Called During Period, Shares Preferred Stock, Redemption Price Per Share Preferred Stock, Redemption Price Per Share Statement of Comprehensive Income [Abstract] Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Income (loss) on interest rate swaps Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Other comprehensive income (loss) Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Income attributable to noncontrolling interest after preferred stock dividends Net Income (Loss) Attributable to Noncontrolling Interest Other comprehensive (income) loss attributable to noncontrolling interest Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Comprehensive income attributable to STAG Industrial, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent Shares Granted (in shares) Vested (in shares) Forfeited (in shares) Fair value of restricted stock per share at grant date Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Fair value of shares vested Schedule of share-based payment award, performance unit awards, valuation assumptions Schedule of Share-based Payment Award, Performance Unit Awards, Valuation Assumptions [Table Text Block] Schedule of Share-based Payment Award, Performance Unit Awards, Valuation Assumptions [Table Text Block] Summary of Equity Compensation Expense Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Acquisitions 2019 [Member] Acquisitions 2019 [Member] Acquisitions 2019 Acquisitions Q1 2019 Acquisitions Q1 2019 [Member] Acquisitions Q1 2019 Florence, KY, 1-24-19 [Member] Florence, KY, 1-24-19 [Member] Florence, KY, 1-24-19 [Member] Burgettstown, PA, 2-21-19 [Member] Burgettstown, PA, 2-21-19 [Member] Burgettstown, PA, 2-21-19 [Member] Taunton, MA, 2-21-19 [Member] Taunton, MA, 2-21-19 [Member] Taunton, MA, 2-21-19 [Member] Blaine, MN, 2-28-19 [Member] Blaine, MN, 2-28-19 [Member] Blaine, MN, 2-28-19 [Member] Piedmont, SC, 3-7-19 [Member] Piedmont, SC, 3-7-19 [Member] Piedmont, SC, 3-7-19 [Member] York, PA, 3-7-19 [Member] York, PA, 3-7-19 [Member] York, PA, 3-7-19 [Member] Omaha, NE, 3-11-19 [Member] Omaha, NE, 3-11-19 [Member] Omaha, NE, 3-11-19 [Member] Humble, TX, 3-28-19 [Member] Humble, TX, 3-28-19 [Member] Humble, TX, 3-28-19 [Member] Elkridge, MD, 3-28-19 [Member] Elkridge, MD, 3-28-19 [Member] Elkridge, MD, 3-28-19 [Member] Houston, TX, 3-28-19 [Member] Houston, TX, 3-28-19 [Member] Houston, TX, 3-28-19 [Member] Number of Buildings Acquired Number of Buildings Acquired Number of Buildings Acquired Business Combination, Consideration Transferred Business Combination, Consideration Transferred Revenue Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Net income (loss) Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Principal outstanding Long-term debt, fair value Long-term Debt, Fair Value Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair value on recurring basis Fair Value, Measurements, Recurring [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Assets (liabilities): Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Interest rate swaps-Asset Interest rate swaps-Liability Equity Incentive Plan Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Over-Allotment Option [Member] Over-Allotment Option [Member] Sale of Stock, Number of Shares Issued in Transaction Sale of Stock, Number of Shares Issued in Transaction Shares Issued, Price Per Share Shares Issued, Price Per Share Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Share-based Compensation Award, Tranche One [Member] Share-based Compensation Award, Tranche One [Member] Assumptions Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract] Expected term (years) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Expected volatility Fair value of LTIP units at issuance (in thousands) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Fair Value LTIP units at issuance Fair value unit price per LTIP unit at issuance Schedule of Stock by Class Schedule of Stock by Class [Table Text Block] Schedule of dividends Dividends Declared [Table Text Block] Schedule of stock sale activity Schedule of Stock Sales [Table Text Block] Tabular disclosure of sales of stock or previously unissued stock under a stock offering program. Does not include sales of stock by subsidiary or equity method investee. Schedule of activity related to unvested restricted stock awards Schedule of Unvested Restricted Stock Units Roll Forward [Table Text Block] Schedule of vested restricted shares of common stock activity Schedule of Vested Restricted Stock Units Activity [Table Text Block] Schedule of Vested Restricted Stock Units Activity [Table Text Block] Income Statement [Abstract] Revenues [Abstract] Revenues [Abstract] Rental income Other income Other Operating Income Total revenue Revenues Expenses Costs and Expenses [Abstract] Property Direct Costs of Leased and Rented Property or Equipment General and administrative General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Loss on impairments Other expenses Other Expenses Total expenses Costs and Expenses Other income (expense) Nonoperating Income (Expense) [Abstract] Interest and other income Interest and Other Income Interest expense Gain on the sales of rental property, net Gain (Loss) on Sale of Properties, before Applicable Income Taxes Total other income (expense) Nonoperating Income (Expense) Net income Less: income attributable to noncontrolling interest after preferred stock dividends Net income attributable to STAG Industrial, Inc. Net Income (Loss) Attributable to Parent Less: preferred stock dividends Preferred Stock Dividends, Income Statement Impact Less: amount allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Net income attributable to common stockholders Net Income (Loss) Available to Common Stockholders, Basic 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 Net income per share — basic and diluted Earnings Per Share, Basic and Diluted [Abstract] Net income per share attributable to common stockholders — basic Income (Loss) from Continuing Operations, Per Basic Share Net income per share attributable to common stockholders — diluted Income (Loss) from Continuing Operations, Per Diluted Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Numerator Net Income (Loss) Attributable to Parent [Abstract] Net income Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: income attributable to noncontrolling interest after preferred stock dividends Income (Loss) from Continuing Operations, Net of Tax, Attributable to Noncontrolling Interest Net income attributable to common stockholders Denominator Weighted Average Number of Shares Outstanding, Diluted [Abstract] Share-based compensation Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount