Quarterly Financial Information Disclosure [Abstract] Quarterly Supplemental Financial Information (unaudited) Quarterly Financial Information [Text Block] Fair Value Disclosures [Abstract] Schedule of Assets Measured on a Non-Recurring Basis Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block] Schedule of the Fair Value of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Debt Disclosure [Abstract] Schedule of Debt Transactions Schedule of Long-term Debt Instruments [Table Text Block] Scheduled Maturities of Mortgage Indebtedness Schedule of Maturities of Long-term Debt [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] 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] Acquired in-place lease Leases, Acquired-in-Place [Member] Acquired above market lease Above Market Leases [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Amortization of: Finite-Lived Intangible Assets, Net [Abstract] Intangible assets Finite-Lived Intangible Assets, Gross Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Intangible assets, net Finite-Lived Intangible Assets, Net Intangible liabilities: Below Market Lease [Abstract] Acquired below market lease Below Market Lease, Gross Accumulated amortization Below Market Lease, Accumulated Amortization Total Below Market Lease, Net Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Mortgages Mortgages [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Dulles Executive Plaza Asset Dulles Executive Plaza Asset [Member] Dulles Executive Plaza Asset [Member] AT&T-Hoffman Estates Asset AT&T-Hoffman Estates Asset [Member] AT&T-Hoffman Estates Asset [Member] AT&T-St. Louis AT&T-St. Louis [Member] AT&T-St. Louis [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Spinoff [Member] Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member] Discontinued Operations, Disposed of by Sale Discontinued Operations, Disposed of by Sale [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] (Loss) gain on extinguishment of debt Gain (Loss) on Extinguishment of Debt Gross Disposition Price Disposal Group, Including Discontinued Operation, Consideration Number of assets (in property) Disposal Group, Including Discontinued Operations, Number of Real Estate Properties Disposal Group, Including Discontinued Operations, Number of Real Estate Properties Gain (loss) on sale of investment properties Gain (Loss) on Sale of Properties, before Applicable Income Taxes Statement of Financial Position [Abstract] Allowance for accounts and rent receivables Allowance for Doubtful Accounts Receivable 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 Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Conversion of Stock [Table] Conversion of Stock [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common stock Common Stock [Member] Conversion of Stock [Line Items] Conversion of Stock [Line Items] Shares issued for each share held at date of spin-off (in shares) Number of Shares Issued in Spinoff for Each Share Owned in Former Parent Number of Shares Issued in Spinoff for Each Share Owned in Former Parent Number of assets (in property) Number of Real Estate Properties Parcels of land Number of Parcels of Land Number of Parcels of Land Share-based Compensation [Abstract] Share Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Subsequent Event [Table] Subsequent Event [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Affiliate Of Acadia Strategic Opportunity Fund V LLC Affiliate Of Acadia Strategic Opportunity Fund V LLC [Member] Affiliate Of Acadia Strategic Opportunity Fund V LLC [Member] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Lincoln, RI Lincoln, Rhode Island [Member] Lincoln, Rhode Island [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Base rate Base Rate [Member] LIBOR London Interbank Offered Rate (LIBOR) [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Letter of credit subfacility Letter of Credit [Member] Term Loan Facility Term Loan Facility [Member] Term Loan Facility [Member] Line of Credit Line of Credit [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Multi-Tenant Residential Multifamily [Member] 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] Number of properties acquired Number Of Real Estate Properties Acquired Number Of Real Estate Properties Acquired Number of units Number of Units in Real Estate Property Acquisition of investment properties Payments to Acquire Real Estate Gross sale price Warranty amount Disposal Group, Agreement Warranty, Amount Disposal Group, Agreement Warranty, Amount Warrant deductible amount Disposal Group, Agreement Warranty, Deductible Amount Disposal Group, Agreement Warranty, Deductible Amount Earnest deposit into escrow Escrow Deposits Related to Property Sales Costs subject to refund Costs Associated With Asset Acquisitions, Amount Subject To Refund Costs Associated With Asset Acquisitions, Amount Subject To Refund Asset held for sale Real Estate Held-for-sale Borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Percentage of capacity Line Of Credit Facility, Percentage Of Available Borrowing Capacity Line Of Credit Facility, Percentage Of Available Borrowing Capacity Additional borrowing capacity, maximum Line Of Credit Facility, Additional Borrowing Capacity Line Of Credit Facility, Additional Borrowing Capacity Draw of credit facility Proceeds from Lines of Credit Number of extension options Line Of Credit Facility, Number Of Extension Options Line Of Credit Facility, Number Of Extension Options Extension period Line Of Credit Facility, Extension Period Line Of Credit Facility, Extension Period Extension fee percentage Debt Instrument, Extension Fee Percentage Debt Instrument, Extension Fee Percentage Variable rate Debt Instrument, Basis Spread on Variable Rate Unused commitment fee percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Summary of Quarterly Financial Information Quarterly Financial Information [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt, net Long-term Debt Weighted average interest rate Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate Deferred financing costs, net Debt Issuance Costs, Net Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Estimated Fair Value Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Mortgages payable Long-term Debt, Fair Value Numerator: Net Income (Loss), Including Portion Attributable to Noncontrolling Interest [Abstract] Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Denominator: Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract] Weighted average shares outstanding - basic and diluted (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Basic and diluted income per share: Earnings Per Share, Basic and Diluted [Abstract] Net income per common share, basic and diluted (in dollars per share) Earnings Per Share, Basic and Diluted Payables and Accruals [Abstract] Accrued real estate taxes Taxes Payable Accrued compensation Employee-related Liabilities Accrued interest payable Interest Payable Other accrued expenses Other Accrued Liabilities Total accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Executive Officer Executive Officer [Member] Two Executive Officers Two Executive Officers [Member] Two Executive Officers [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Incentive awards Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Aggregate value of shares granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Number of employees affected Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Number of Employees Affected Incremental compensation cost, plan modification Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost Number of shares authorized to grant (up to) (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Shares available for future issuance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Stock-based compensation expense Allocated Share-based Compensation Expense Unrecognized compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Payment for tax withholding for share-based compensation Payments Related to Tax Withholding for Share-based Compensation Stock Awards Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward] Beginning balance (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Ending balance (in shares) Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Beginning balance (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Ending balance (in dollars per share) Intangible Assets Intangible Assets Disclosure [Text Block] Accounting Policies [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Discount rate Measurement Input, Discount Rate [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU 2016-02 Accounting Standards Update 2016-02 [Member] ASU 2016-18 Accounting Standards Update 2016-18 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Lease liability Operating Lease, Liability ROU asset Operating Lease, Right-of-Use Asset Measurement input Debt Instrument, Measurement Input Net cash flows used in financing activities Net Cash Provided by (Used in) Financing Activities Restricted cash Restricted Cash Increase in beginning balance Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Beginning Balance Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Beginning Balance Increase in ending balance Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Ending Balance Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Ending Balance Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Total cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Nonrecurring Fair Value, Measurements, Nonrecurring [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Net Lease Net Lease [Member] Net Lease [Member] 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 and improvements Building and Building Improvements [Member] Furniture, fixtures, equipment and site improvements Furniture, Fixtures, Equipment and Site Improvements [Member] Furniture, Fixtures, Equipment and Site Improvements [Member] Estimated useful lives Property, Plant and Equipment, Useful Life Assets held for sale Assets Held-for-sale, Not Part of Disposal Group Provision for asset impairment Asset Impairment Charges Number of leased assets, impaired Number of Leased Assets, as Lessor, Impaired Number of Leased Assets, as Lessor, Impaired Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Revenue Recognition Revenue Recognition Leases, Operating [Policy Text Block] Capitalization and Depreciation Depreciation and Amortization of Property, Plant and Equipment, Leasing Fees and Loan Fees, and Capitalized Costs, Policy [Policy Text Block] Depreciation and Amortization of Property, Plant and Equipment, Leasing Fees and Loan Fees, and Capitalized Costs, Policy [Policy Text Block] Assets Held for Sale Real Estate Held for Development and Sale, Policy [Policy Text Block] Impairment Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Recently Issued Accounting Pronouncements and Recently Adopted Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Leases [Abstract] Leases Lessor, Operating Leases [Text Block] Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] 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 Total Operating Leases, Future Minimum Payments Receivable 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] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Revenue Sales Revenue, Net [Member] Property Subject to or Available for Operating Lease [Line Items] Property Subject to or Available for Operating Lease [Line Items] Remaining lease terms Lessor, Operating Lease, Term of Contract Concentration risk percentage Concentration Risk, Percentage Asset Acquisitions [Abstract] Asset Acquisitions [Abstract] Schedule of Asset Acquisitions, by Acquisition [Table] Schedule of Asset Acquisitions, by Acquisition [Table] Schedule of Asset Acquisitions, by Acquisition [Table] Multi-family Schedule of Asset Acquisitions, by Acquisition [Line Items] Schedule of Asset Acquisitions, by Acquisition [Line Items] [Line Items] for Schedule of Asset Acquisitions, by Acquisition [Table] Capitalized transaction costs Asset Acquisition, Capitalized Transaction Costs Asset Acquisition, Capitalized Transaction Costs Disposed Assets Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Tenant recovery income Real Estate, Tenant Recovery [Member] Real Estate, Tenant Recovery [Member] Other property income Real Estate, Other [Member] Total revenues Real Estate [Member] Retail Retail [Member] Multi-Tenant Office Multi-Tenant Office [Member] Multi-Tenant Office [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating segments Operating Segments [Member] Other Corporate, Non-Segment [Member] Reconciling items Segment Reconciling Items [Member] Operating segments and corporate, non-segment Operating Segments And Corporate, Non-Segment [Member] Operating Segments And Corporate, Non-Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Rental income Operating Leases, Income Statement, Lease Revenue Total revenues Revenue from Contract with Customer, Excluding Assessed Tax Operating expenses Cost of Real Estate Revenue and Real Estate Tax Expense Cost of Real Estate Revenue and Real Estate Tax Expense Net operating income (loss) Operating Income (Loss), Net of Non-Allocated Expenses Operating Income (Loss), Net of Non-Allocated Expenses Non-allocated expenses General and Administrative Expense, Depreciation and Amortization General and Administrative Expense, Depreciation and Amortization Other income and expenses Income Tax Expense, Interest Expense and Other Loss Income Tax Expense, Interest Expense and Other Loss Provision for asset impairment Net income (loss) attributable to Company Net Income (Loss) Attributable to Parent Balance Sheet Data Segment Reconciliation [Abstract] Total assets Assets Capital expenditures Payments to Acquire and Develop Real Estate SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract] Schedule III Real Estate and Accumulated Depreciation SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Amortization and Accretion, Net Amortization of above and below market leases, net Amortization of above and below Market Leases Amortization of debt discounts and financing costs Amortization of Debt Issuance Costs and Discounts Straight-line rental income Straight Line Rent Loss (gain) on extinguishment of debt Gain on sale of investment properties, net Gain (Loss) on Sale of Properties Non-cash stock-based compensation expense Share-based Compensation Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Accounts and rents receivable, net Increase (Decrease) in Receivables Settlement of balance due from InvenTrust Increase (Decrease) in Due from Related Parties, Current Deferred costs and other assets Increase (Decrease) in Deferred Charges Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Other liabilities Increase (Decrease) in Other Operating Liabilities Net cash flows 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] Capital expenditures and tenant improvements Proceeds from sale of investment properties, net Proceeds from Sale of Real Estate Held-for-investment Acquisition of investment properties Proceeds from insurance settlement Proceeds from Insurance Settlement, Investing Activities Payment of leasing fees Payments for Leasing Costs Net cash flows 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] Payoff of mortgage debt Repayments of Notes Payable, Paid Off Repayments of Notes Payable, Paid Off Prepayment penalties on the payoff of mortgage debt Payment for Debt Extinguishment or Debt Prepayment Cost Prepayment penalties on the payoff of mortgage debt Payments For Early Extinguishment Of Debt Prepayment Penalties Payments For Early Extinguishment Of Debt Prepayment Penalties Principal payments of mortgage debt Repayments of Mortgage, Principal Repayments of Mortgage, Principal Payment for tax withholding for share-based compensation Net cash flows used in financing activities Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash, cash equivalents and restricted cash, at beginning of year Cash, cash equivalents and restricted cash, at end of year Schedule Of Asset Acquisitions Schedule Of Asset Acquisitions [Table Text Block] Schedule Of Asset Acquisitions [Table Text Block] Summary of Stock Award Activity Share-based Compensation, Activity [Table Text Block] Income tax benefit (expense) Income Tax Expense (Benefit) U.S. federal excise tax accrual Sales and Excise Tax Payable Unrecognized tax benefits Unrecognized Tax Benefits Summary of Net Property Operations Schedule of Segment Reporting Information, by Segment [Table Text Block] Income Statement [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] Revenues Revenues [Abstract] Expenses Operating Expenses [Abstract] Property operating expenses Cost of Goods and Services Sold Real estate taxes Real Estate Tax Expense Depreciation and amortization Depreciation and Amortization, Net of Lease Inducements Depreciation and Amortization, Net of Lease Inducements General and administrative expenses General and Administrative Expense Total expenses Operating Expenses Gain on sale of investment properties Income (loss) from operations Operating Income (Loss) Interest income Investment Income, Interest and Dividend Other income Other Nonoperating Gains (Losses) Interest expense Interest Expense Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Net income Weighted average number of common shares outstanding, basic and diluted (in shares) Schedule of Minimum Lease Payments to Be Received Schedule of Future Minimum Rental Payments Receivable for Operating Leases [Table Text Block] Schedule of Future Minimum Rental Payments Receivable for Operating Leases [Table Text Block] Fair Value Measurements Fair Value Disclosures [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Investment properties Property, Plant, and Equipment, Fair Value Disclosure Term of discounted cash flow model Fair Value Assumptions, Impairment Analysis, Discounted Cash Flow Model Fair Value Assumptions, Impairment Analysis, Discounted Cash Flow Model Capitalization rate Fair Value Assumptions, Capitalization Rate Fair Value Assumptions, Capitalization Rate Leased asset measurement input Finance Leased Asset, Measurement Input Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] The Lafayette The Lafayette [Member] The Lafayette [Member] 1620 Central Street 1620 Central Street [Member] 1620 Central Street [Member] Kenilworth Court Kenilworth Court [Member] Kenilworth Court [Member] 2019 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2020 Long-term Debt, Maturities, Repayments of Principal in Year Two 2021 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt, Maturities, Repayments of Principal in Year Four 2023 Long-term Debt, Maturities, Repayments of Principal in Year Five Total Long-term Debt, Gross Weighted average interest rate Interest Costs Incurred [Abstract] 2019 Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Next 12 Months Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Next 12 Months 2020 Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Two Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Two 2021 Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Three Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Three 2022 Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Four Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Four 2023 Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Five Long-term Debt, Maturities, Repayments of Principal, Weighted Average Interest Rate, Year Five Total Schedule of Cash and Restricted Cash Schedule of Cash and Cash Equivalents [Table Text Block] Assets Assets [Abstract] Investment properties Real Estate Investment Property, Net [Abstract] Land Land Building and other improvements Investment Building and Building Improvements Construction in progress Development in Process Total Real Estate Investment Property, at Cost Less accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Net investment properties Real Estate Investment Property, Net Restricted cash and escrows Accounts and rents receivable (net of allowance of $1,161 and $850) Accounts Receivable, Net Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Deferred costs and other assets Deferred Costs and Other Assets Total assets Liabilities Liabilities [Abstract] Accounts payable and accrued expenses Intangible liabilities, net Other liabilities Other Liabilities Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Stockholders’ Equity Stockholders' Equity Attributable to Parent [Abstract] Common stock, $0.01 par value, 1,000,000,000 shares authorized, 871,688,704 shares issued and outstanding as of December 31, 2018 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Accumulated distributions in excess of net income Accumulated Distributions in Excess of Net Income Total stockholders’ equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and stockholders' equity Liabilities and Equity Amortization of: Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] 2019 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 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 Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Acquired below market lease Below Market Lease, Net, Amortization Income, Fiscal Year Maturity [Abstract] 2019 Below Market Lease, Amortization Income, Next Twelve Months 2020 Below Market Lease, Amortization Income, Year Two 2021 Below Market Lease, Amortization Income, Year Three 2022 Below Market Lease, Amortization Income, Year Four 2023 Below Market Lease, Amortization Income, Year Five Thereafter Below Market Lease, Amortization Income, after Year Five Net rental income increase, 2019 Amortization Expense (Income) of above and below Market Leases, Next Twelve Months Amortization Expense (Income) of above and below Market Leases, Next Twelve Months Net rental income increase, 2020 Amortization Expense (Income) of above and below Market Leases, Year Two Amortization Expense (Income) of above and below Market Leases, Year Two Net rental income increase, 2021 Amortization Expense (Income) of above and below Market Leases, Year Three Amortization Expense (Income) of above and below Market Leases, Year Three Net rental income increase, 2022 Amortization Expense (Income) of above and below Market Leases, Year Four Amortization Expense (Income) of above and below Market Leases, Year Four Net rental income increase, 2023 Amortization Expense (Income) of above and below Market Leases, Year Five Amortization Expense (Income) of above and below Market Leases, Year Five Net rental income increase, Thereafter Amortization Expense (Income) of above and below Market Leases, Thereafter Amortization Expense (Income) of above and below Market Leases, Thereafter Net rental income increase, Total Amortization Expense (Income) of above and below Market Leases, Net, Total Amortization Expense (Income) of above and below Market Leases, Net, Total Schedule of Sales Activity and Operations Disposal Groups, Including Discontinued Operations [Table Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Entity Filer Category Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Entity Current Reporting Status Entity Current Reporting Status Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Ex Transition Period Entity Ex Transition Period Entity Shell Company Entity Shell Company Entity Voluntary Filers Entity Voluntary Filers Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Public Float Entity Public Float Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Movement in Debt [Roll Forward] Movement in Debt [Roll Forward] Movement in Debt [Roll Forward] Beginning Balance Transfer of mortgages payable to lenders Transfer Mortgage Payable Paydown of debt Repayments of Debt Ending Balance Total expenses (Loss) gain on sale of investment properties Income (loss) from operations Other income (loss) (Loss) income before income taxes Net (loss) income Net (loss) income per common share, basic and diluted (in dollars per share) Organization Nature of Operations [Text Block] Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Cash paid for taxes Income Taxes Paid Supplemental schedule of non-cash investing and financing activities: Other Noncash Investing and Financing Items [Abstract] Non-cash accruals for capital expense and investment in development Capital Expenditures Incurred but Not yet Paid Mortgage loans payable and related obligations settled Transfer Mortgage Payable And Related Obligations Settled Transfer Mortgage Payable And Related Obligations Settled Real estate transferred to mortgage lender Real Estate Owned, Transfer to Real Estate Owned Segment Reporting Segment Reporting Disclosure [Text Block] Intangible assets Amortization of Intangible Assets Acquired below market lease Amortization of Below Market Lease Net rental income increase Debt Debt Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Common Stock Additional Paid-in Capital Additional Paid-in Capital [Member] Accumulated Distributions in Excess of Net Income Accumulated Distributions in Excess of Net Income [Member] Beginning balance Beginning balance (in shares) Shares, Outstanding Share-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation and Exercise of Stock Options Share-based compensation (in shares) Stock Issued During Period, Shares, Share-based Compensation, Gross Ending balance (in shares) Ending balance Reconciliation of Net (Loss) Income to Basic and Diluted EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Acquired Assets Asset Acquisitions [Text Block] Asset Acquisitions [Text Block] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, by Property [Table] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, by Property [Table] Retail Retail Site [Member] Net Lease Other Other Property [Member] BUCKHORN PLAZA Buckhorn Plaza [Member] Buckhorn Plaza [Member] LINCOLN MALL Lincoln Mall [Member] Lincoln Mall [Member] SHERMAN PLAZA Sherman Plaza [Member] Sherman Plaza [Member] STATE STREET MARKET State Street Market [Member] State Street Market [Member] THE MARKET AT HILLIARD The Market at Hilliard [Member] The Market at Hilliard [Member] CITIZENS (CFG) RHODE ISLAND Citizens (CFG) Rhode Island [Member] Citizens (CFG) Rhode Island [Member] ATLAS - ST PAUL Atlas - St. Paul [Member] Atlas - St. Paul [Member] ATLAS-NEW ULM Atlas - New Ulm [Member] Atlas - New Ulm [Member] HUDSON CORRECTIONAL FACILITY Hudson Correctional Facility [Member] Hudson Correctional Facility [Member] TRIMBLE I Trimble I [Member] Trimble I [Member] BUERGER BROTHER LOFTS Buerger Brothers Lofts [Member] Buerger Brothers Lofts [Member] CHAMBER LOFTS Chamber Lofts [Member] Chamber Lofts [Member] THE LAFAYETTE KENILWORTH COURT 1620 CENTRAL STREET PALAZZO DEL LAGO Palazzo Del Lago [Member] Palazzo Del Lago [Member] RDU Land RDU Land [Member] RDU Land [Member] Bloomsburg, PA Bloomsburg, Pennsylvania [Member] Bloomsburg, Pennsylvania [Member] Evanston, IL Evanston, Illinois [Member] Evanston, Illinois [Member] Rockford, IL Rockford, Illinois [Member] Rockford, Illinois [Member] Hilliard, OH Hilliard, Ohio [Member] Hilliard, Ohio [Member] Providence, RI Providence, Rhode Island [Member] Providence, Rhode Island [Member] St. Paul, MN St. Paul, Minnesota [Member] St. Paul, Minnesota [Member] New Ulm, MN New Ulm, Minnesota [Member] New Ulm, Minnesota [Member] Hudson, CO Hudson, Colorado [Member] Hudson, Colorado [Member] San Jose, CA San Jose, California [Member] San Jose, California [Member] Denver, CO Denver, Colorado [Member] Denver, Colorado [Member] Orlando, FL Orlando, Florida [Member] Orlando, Florida [Member] Raleigh, NC Raleigh, North Carolina [Member] Raleigh, North Carolina [Member] Furniture, fixtures, & equipment Furniture and Fixtures [Member] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation [Line Items] Encumbrance SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Amount of Encumbrances Initial Cost, Land SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Land Initial Cost, Buildings and Improvements SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Initial Cost of Building and Improvements Adjustments to Land Basis SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized and Impairment of Real Estate Subsequent to Acquisition, Land SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized and Impairment of Real Estate Subsequent to Acquisition, Land Adjustments to Building Basis SEC Schedule III Real Estate and Accumulated Depreciation, Costs Capitalized and Impairment of Real Estate Subsequent to Acquisition, Buildings and Improvements SEC Schedule III Real Estate and Accumulated Depreciation, Costs Capitalized and Impairment of Real Estate Subsequent to Acquisition, Buildings and Improvements Gross amount at which carried at end of period, Land and Improvements SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Land, Amount Gross amount at which carried at end of period, Buildings and Improvements SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Building and Improvements, Amount Gross amount at which carried at end of period, Total SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Gross Accumulated Depreciation SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation Notes to Schedule III SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, and Accumulated Depreciation, Other Disclosure [Abstract] Cost of real estate owned SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Federal Income Tax Basis SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward] Beginning balance Acquisitions and capital improvements SEC Schedule III, Real Estate, Acquisitions and Improvements SEC Schedule III, Real Estate, Acquisitions and Improvements Dispositions and write-offs SEC Schedule III, Real Estate, Dispositions and Write-Offs, Amount SEC Schedule III, Real Estate, Dispositions and Write-Offs, Amount Asset impairments SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Write-down or Reserve, Amount Ending balance SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward] SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward] Beginning balance Depreciation expense SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation, Depreciation Expense Dispositions and write-offs SEC Schedule III, Real Estate Accumulated Depreciation, Dispositions and Write-Offs SEC Schedule III, Real Estate Accumulated Depreciation, Dispositions and Write-Offs Asset impairments SEC Schedule III, Real Estate Accumulated Depreciation, Asset Impairment SEC Schedule III, Real Estate Accumulated Depreciation, Asset Impairment Ending balance Estimated lives upon which depreciation is computed SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation, Life Used for Depreciation Concentration Risk [Table] Concentration Risk [Table] Concentration Risk [Line Items] Concentration Risk [Line Items] Number of business segments (in segments) Number of Operating Segments Number of leased assets Number of Leased Assets, as Lessor Number of Leased Assets, as Lessor Buckhorn Plaza Rolling Plains Rolling Plains [Member] Rolling Plains [Member] Triangle Center Triangle Center [Member] Triangle Center [Member] Bridgeside Point Bridgeside Point Office Building [Member] Bridgeside Point Office Building [Member] Denver Highlands Denver Highlands [Member] Denver Highlands [Member] Sand Lake land Sand Lake Land [Member] Sand Lake Land [Member] North Pointe land North Pointe Land [Member] North Pointe Land [Member] Number of parcels of land Disposal Group, Including Discontinued Operations, Number Of Parcels Of Land Disposal Group, Including Discontinued Operations, Number Of Parcels Of Land Extinguishment of debt Extinguishment of Debt, Amount Accounts Payable and Accrued Expenses Accounts Payable and Accrued Liabilities Disclosure [Text Block] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Long-term debt Long-term Debt [Member] Long term debt measurement input Long-term Debt, Measurement Input Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Schedule of Accounts Payable and Accrued Expenses Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Summary of identified intangible assets and intangible liabilities Schedule of Finite-Lived Intangible Assets [Table Text Block] Summary of amortization of identified intangible assets and liabilities Finite-lived Intangible Assets Amortization Expense [Table Text Block] Summary of accretion income for below market leases Below Market Lease, Future Amortization Income [Table Text Block]