Discontinued Operations and Disposal Groups [Abstract] 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] Properties that have been sold or classified as held for sale Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Revenues Disposal Group, Including Discontinued Operation, Revenue Operating expenses Disposal Group, Including Discontinued Operation, Operating Expense Gain on sale of real estate, net Disposal Group, Including Discontinued Operation, Gains (Losses) on Sales of Investment Real Estate Disposal Group, Including Discontinued Operation, Gains (Losses) on Sales of Investment Real Estate Interest expense Disposal Group, Including Discontinued Operation, Interest Expense Other gains and (losses) Disposal Group, Including Discontinued Operation, Other Expense (Provision for) benefit from income taxes Discontinued Operation, Tax Effect of Discontinued Operation Net income attributable to noncontrolling interests Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest Income (loss) from properties sold, net of income taxes Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Variable Interest Entities Schedule of Variable Interest Entities [Table Text Block] Reconciliation of Cash and Cash Equivalents Schedule of Cash and Cash Equivalents [Table Text Block] Restrictions on Cash and Cash Equivalents Restrictions on Cash and Cash Equivalents [Table Text Block] Schedule of Details of Accounts Receivables, Accounts Payable, and Other Assets and Liabilities Schedule of Other Assets and Other Liabilities [Table Text Block] Real Estate [Abstract] Operating Leases, Lease Income Operating Leases, Lease Income [Abstract] Lease income — fixed Operating Lease, Lease Income, Lease Payments Lease income — variable Operating Lease, Variable Lease Income Total operating lease income Operating Lease, Lease Income Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative [Table] Derivative [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest expense Interest Expense [Member] Other income Other Operating Income (Expense) [Member] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Individual Counterparty Individual Counterparty [Member] Derivative Derivative [Line Items] Cash collateral posted Derivative Asset, Collateral, Obligation to Return Cash, Offset Estimated amount of derivative gain (loss) to be reclassified in the next 12 months Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred Derivative instrument remaining maturity period Derivative, Remaining Maturity Collateral received Derivative, Collateral, Obligation to Return Cash Total credit exposure Credit Derivative, Maximum Exposure, Undiscounted Derivative in net liability position Derivative, Net Liability Position, Aggregate Fair Value Termination value of assets Assets Needed for Immediate Settlement, Aggregate Fair Value Property Dispositions Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Basic, by Common Class, Including Two Class Method [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Class A common stock Common Class A [Member] Class C common stock Common Class C [Member] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items] Basic and Diluted Earnings Per Share, Basic and Diluted [Abstract] Weighted-Average Shares Outstanding (shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Allocation of Net Income Net Income (Loss) Attributable to Parent Basic and diluted earnings per share (in dollars per share) Earnings Per Share, Basic and Diluted Fair Value Disclosures [Abstract] Schedule of Other Financial Instruments In Carrying Values And Fair Values Schedule Of Other Financial Instruments In Carrying Values And Fair Values [Table Text Block] Tabular disclosure of other financial instruments at carrying value and fair value. Subsequent Events [Abstract] Subsequent Events Subsequent Events [Text Block] Real Estate, Operating Real Estate, Real Estate Under Construction, and Equity Investment in Real Estate Real Estate Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Net Lease Net Lease Segment [Member] Net Lease Segment [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Agrokor Croatia [Member] Croatia Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Segment Reporting Information Segment Reporting Information [Line Items] Number of reportable segments Number of Reportable Segments Straight line rent adjustment Straight Line Rent Adjustments Percentage of contractual rents collected (percent) Percentage Of Contractual Rents Collected Percentage Of Contractual Rents Collected Bad debt expense Allowance for Doubtful Accounts Receivable, Write-offs Percentage of rents converted to debt (percent) Percentage Of Rents Settled With Convertible Instruments Percentage Of Rents Settled With Convertible Instruments Receivables [Abstract] Direct Financing Lease Future Lease Future Lease Payments Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract] 2019 (remainder) Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Remainder of Fiscal Year 2020 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Two Years 2021 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Three Years 2022 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Four Years 2023 Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Five Years Thereafter Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received, Thereafter Total undiscounted cash flows Sales-type and Direct Financing Leases, Lease Receivable, Payments to be Received Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Mortgage Loans On Real Estate Interest Rate [Axis] Mortgage Loans On Real Estate Interest Rate [Axis] Mortgage Loans On Real Estate Interest Rate Mortgage Loans On Real Estate Interest Rate [Domain] Mortgage Loans On Real Estate Interest Rate [Domain] Mortgage Loans On Real Estate Interest Rate Fixed Interest Rate Fixed Interest Rate [Member] Fixed Interest Rate Variable Interest Rate Variable Interest Rate [Member] Variable Interest Rate Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Student Housing in Austin, Texas Student Housing in Austin, Texas [Member] Student Housing in Austin, Texas [Member] Student Housing in Barcelona, Spain Student Housing in Barcelona, Spain [Member] Student Housing in Barcelona, Spain [Member] Student Housing in Portsmouth, United Kingdom Student Housing in Portsmouth, United kingdom [Member] Student Housing in Portsmouth, United kingdom [Member] Student Housing in Cardiff, United Kingdom Cardiff [Member] Cardiff [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] Development Asset under Construction [Member] Furniture, fixtures and equipment Furniture Fixtures and Equipment [Member] Furniture Fixtures and Equipment [Member] Additional development Additional Asset under Construction [Member] Additional Asset under Construction [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Long-term debt Long-term Debt [Member] Accounts receivable and other assets, net Accounts Receivable and Other Assets, net [Member] Accounts Receivable and Other Assets, net [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instruments Debt Instruments [Abstract] Mortgage loan on real estate, interest rate SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate Debt instrument range, beginning Debt Instrument, Maturity Date Range, Start Debt instrument range, ending Debt Instrument, Maturity Date Range, End Debt instrument maximum borrowing amount Line of Credit Facility, Maximum Borrowing Capacity Variable interest rate (percent) Debt Instrument, Interest Rate During Period Option extension period Debt Instrument, Option Maturity Extension Period Debt Instrument, Option Maturity Extension Period Construction loan Construction Loan Stated interest rate (percent) Debt Instrument, Interest Rate, Stated Percentage Proceeds from mortgage financing Proceeds from Issuance of Secured Debt Effect of exchange rate fluctuation Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Restricted cash Restricted Cash Related Party Transactions [Abstract] Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Affiliated Entity Affiliated Entity [Member] W.P. Carey W.P. Carey [Member] W.P. Carey [Member] Advisor Advisor [Member] Advisor [Member] Related Party Fees Basis [Axis] Related Party Fees Basis [Axis] -- None. No documentation exists for this element. -- Related Party Fees Basis [Domain] Related Party Fees Basis [Domain] -- None. No documentation exists for this element. -- Average market value of investment Average Market Value Of Investment [Member] Average Market Value Of Investment [Member] Average equity value of investment Average Equity Value Of Investment [Member] Average Equity Value Of Investment [Member] Real estate commission Real Estate Commission [Member] Real Estate Commission [Member] Contract sales price of investment Contract Sales Price Of Investment [Member] Contract Sales Price Of Investment [Member] Average invested asset Average Invested Assets [Member] Average invested assets Adjusted net income Adjusted Net Income [Member] Adjusted Net Income [Member] Class of Stock [Domain] Class C Accounts payable, accrued expenses and other liabilities Accounts Payable and Accrued Liabilities [Member] Settlement Term [Axis] Settlement Term [Axis] -- None. No documentation exists for this element. -- Settlement Term [Domain] Settlement Term [Domain] -- None. No documentation exists for this element. -- Current Current [Member] Current [Member] Deferred Deferred [Member] Deferred [Member] Related Party Transaction Related Party Transaction [Line Items] Advisory agreement, term Advisory Agreement, Term Advisory Agreement, Term Advisory agreement additional renewal period. term Advisory Agreement Additional Renewal Period. Term Advisory Agreement Additional Renewal Period. Term Advisory agreement, unpenalized cancellation period Advisory Agreement, Unpenalized Cancellation Window Advisory Agreement, Unpenalized Cancellation Window Due from advisor Due from Affiliate, Current Maximum line of credit approved by directors Loan from related party Notes Payable, Related Parties Asset management fees (as a percentage) Percentage Of Asset Management Fees The percentage fee paid to the advisor for managing the company's assets based on the average market value or average equity value, as applicable, depending on the type of investments. Net asset value (usd per share) Net Asset Value Per Share Percentage of asset management fees payable in shares (percent) Asset Management Fees Payable In Shares Percent Of Total Asset Management Fees Payable In Shares Percent Of Total Percentage of asset management fees payable in cash (percent) Asset Management Fees Payable In Cash Percent Of Total Asset Management Fees Payable In Cash Percent Of Total Number of shares held by advisor (shares) Common Stock, Shares, Outstanding Advisor owned percentage of common stock Percentage Of Total Common Stock Outstanding Held By Related Party The percentage of our common stock outstanding held by our advisor. Due to Related Party Due to Related Parties [Abstract] Shareholder servicing fee (as a percentage) Shareholder Servicing Fee The percentage due to the dealer manager based on the sale of Class C Shares. Underwriting compensation limit (as a percentage) Underwriting Compensation Limit The percentage of gross offering proceeds related to the limit on underwriting compensation prescribed by Financial Industry Regulatory Authority, Inc. Estimated future payments Shareholder Servicing Fee Payable The amount of shareholder servicing fees that are payable. Preferred return (as a percentage) Preferred Return The advisor's preferred non-compounded cumulative distribution return per annum. Acquisition fees (as a percentage) Percentage of Acquisition Fees The percentage of fees paid to the advisor for the structuring and negotiating investments on the company's behalf and based on the aggregate total costs of an investment for all investments other than those in readily-marketable real estate securities purchased in the secondary market. Interest rate on deferred acquisition fee Interest Rate On Deferred Acquisition Fee Interest Rate On Deferred Acquisition Fee Subordinated disposition fees (as a percentage) Percentage Of Subordinated Disposition Fees The percentage fee based on the lesser of competitive real estate commission or the contract sales prices of the investment being sold that is paid to the advisor for services provided in connection with disposition. Disposition fees Related Party Disposition Fees Related Party Disposition Fees Personnel and overhead reimbursement (as a percentage) Personnel and Overhead Reimbursement, Percentage The percentage threshold for personnel and overhead reimbursement chargeable by the advisor for personnel cost. Personnel expenses excludes costs related to the advisor’s legal transaction group allocated. The threshold is based on pro rata revenue. Legal fee reimbursement rate Legal Fee Reimbursement Rate The percentage of total investment cost reimbursable to the advisor for legal fees. Percentage of operating expense reimbursement Percentage Of Operating Expenses Reimbursements The percentage guideline for when the advisor is required to reimburse the amount of operating expenses that exceeds the greater of the percentages for average invested assets or adjusted net income. Distributions of available cash (as a percentage) Distributions of Available Cash, Percentage Distributions of Available Cash, Percentage Ownership Interest In joint venture (percentage) Ownership Interest In Joint Venture The ownership interest in jointly owned investments by the reporting entity. Earnings Per Share and Equity Stockholders' Equity Note Disclosure [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Cipriani Cipriani [Member] Cipriani [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Third Party Third Party [Member] Third Party [Member] Property Leased to Mills Fleet Farm Group LLC Property Leased to Mills Fleet Farm Group LLC [Member] Property Leased to Mills Fleet Farm Group LLC [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Accounts, Notes, Loans and Financing Receivable Accounts, Notes, Loans and Financing Receivable [Line Items] Notes receivable, principal amount Receivable with Imputed Interest, Face Amount Accounts receivable, term Accounts Receivable, Term Accounts Receivable, Term Senior notes Senior Notes Stated interest rate (percent) Finance Receivable Stated Interest Rate Finance Receivable Stated Interest Rate Notes receivable Receivable with Imputed Interest, Net Amount Number of properties Number of Real Estate Properties Variable rate (percent) Accounts Receivable, Variable Interest Rate Accounts Receivable, Variable Interest Rate Proceeds from repayment of notes receivable Proceeds from Collection of Notes Receivable Interest income from direct financing lease Direct Financing Lease, Interest Income Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Fair Value Measurements Fair Value Disclosures [Text Block] Basis of Presentation Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Derivatives in Cash Flow Hedging Relationships Cash Flow Hedging [Member] Derivatives in Net Investment Hedging Net Investment Hedging [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Foreign currency collars Foreign Currency Collars [Member] Foreign Currency Collars [Member] Foreign currency forward contracts Foreign Exchange Contract [Member] Interest rate caps Interest Rate Cap [Member] Derivative Instruments, Gain (Loss) Derivative Instruments, Gain (Loss) [Line Items] Amount of Gain (Loss) Recognized on Derivatives in Other Comprehensive Income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Future Lease Payments Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Capital Leases, Future Minimum Payments Due, Next Twelve Months 2020 Capital Leases, Future Minimum Payments Due in Two Years 2021 Capital Leases, Future Minimum Payments Due in Three Years 2022 Capital Leases, Future Minimum Payments Due in Four Years 2023 Capital Leases, Future Minimum Payments Due in Five Years Thereafter Capital Leases, Future Minimum Payments Due Thereafter Total undiscounted cash flows Capital Leases, Future Minimum Payments Due Class A Stock-based Compensation Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Distributions Declared Equity Distributions [Abstract] Equity Distributions [Abstract] Interest expense Interest Expense Distributions declared per share (in dollars per share) Common Stock, Dividends, Per Share, Declared Dividends payment Dividends Payable, Date to be Paid Distributions payable Dividends Payable Debt, net Debt Disclosure [Text Block] Lease payments receivable Direct Financing Lease, Lease Receivable Unguaranteed residual value Direct Financing Lease, Unguaranteed Residual Asset Gross investments in direct financing leases Direct Financing Lease, Net Investment in Lease, Excluding Deferred Selling Profit Direct Financing Lease, Net Investment in Lease, Excluding Deferred Selling Profit Less: unearned income Direct Financing Lease, Deferred Selling Profit Net investment in direct financing leases Direct Financing Lease, Net Investment in Lease Lease payments receivable Capital Leases, Net Investment in Direct Financing Leases, Minimum Payments to be Received Unguaranteed residual value Capital Leases, Net Investment in Direct Financing Leases, Unguaranteed Residual Values of Leased Property Gross investments in direct financing leases Capital Leases Net Investment In Direct Financing Leases Excluding Unearned Income The net investment in direct financing leases as of the balance sheet date consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs; less: (i) executory costs, and (ii) the accumulated allowance for uncollectible minimum lease payments. Less: unearned income Capital Leases, Net Investment in Direct Financing Leases, Deferred Income Net investments in direct financing leases Capital Leases, Net Investment in Direct Financing Leases Statement of Comprehensive Income [Abstract] Net Income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other Comprehensive (Loss) Income Other Comprehensive Income (Loss), Net of Tax [Abstract] Foreign currency translation adjustments Unrealized loss on derivative instruments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Other Comprehensive (Loss) Income Other Comprehensive Income (Loss), Net of Tax Comprehensive Income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Amounts Attributable to Noncontrolling Interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest [Abstract] Net income Net Income (Loss) Attributable to Noncontrolling Interest Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive Income Attributable to CPA:18 – Global Comprehensive Income (Loss), Net of Tax, Attributable to Parent Reconciliation of Revenue from Segments to Consolidated Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Reconciliation of Assets from Segment to Consolidated Reconciliation of Assets from Segment to Consolidated [Table Text Block] Statement of Cash Flows [Abstract] Cash Flows — Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net Cash Provided by Operating Activities Net Cash Provided by (Used in) Operating Activities Cash Flows — Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Funding and advances for build-to-suit and development projects Payments for Construction in Process Proceeds from sale of real estate Proceeds from Sale of Real Estate Held-for-investment Acquisitions of real estate, build-to-suit and development projects Payments to Acquire Real Estate and Real Estate Joint Ventures Value added taxes paid in connection with acquisitions of real estate Vat Paid In Connection With Acquisition Of Real Estate Value added tax paid in connection with investments in foreign properties. Payment of deferred acquisition fees to an affiliate Payment Of Deferred Acquisition Fees To Affiliate Total cash payment made to the advisor for asset acquisitions during the reporting period for structuring transactions on behalf of the reporting entity. Value added taxes refunded in connection with acquisitions of real estate VAT refunded in connection with acquisitions in real estate VAT refunded to the Company in connection with acquisitions in real estate. Capital expenditures on real estate Payments to Develop Real Estate Assets Proceeds from insurance settlements Proceeds from Insurance Settlement, Investing Activities Capital contributions to equity investment Payments to Acquire Equity Method Investments Net Cash Used in Investing Activities Net Cash Provided by (Used in) Investing Activities Cash Flows — Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Distributions paid Payments of Ordinary Dividends, Common Stock Scheduled payments and prepayments of mortgage principal Repayments of Secured Debt Proceeds from issuance of shares Proceeds from Issuance of Common Stock Distributions to noncontrolling interests Payments to Noncontrolling Interests Repurchase of shares Payments for Repurchase of Common Stock Contributions from noncontrolling interests Proceeds from Noncontrolling Interests Other financing activities, net Proceeds from (Payments for) Other Financing Activities Payment of deferred financing costs and mortgage deposits Payments of Financing Costs Net Cash (Used in) Provided by Financing Activities Net Cash Provided by (Used in) Financing Activities Change in Cash and Cash Equivalents and Restricted Cash During the Period Cash and Cash Equivalents, Period Increase (Decrease) [Abstract] Effect of exchange rate changes on cash and cash equivalents and restricted cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Net (decrease) increase 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, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents and restricted cash, end of period Disposed of by Sale Discontinued Operations, Disposed of by Sale [Member] Muti-family Home in Fort Walton Beach, FL Muti-family Home in Fort Walton Beach, FL [Member] Muti-family Home in Fort Walton Beach, FL [Member] Retail building located in Edinburgh, United Kingdom Retail Building Located In Edinburgh, United Kingdom [Member] Retail Building Located In Edinburgh, United Kingdom [Member] Non-recourse mortgages, net, including debt attributable to Assets held for sale Non Recourse Debt [Member] Non Recourse Debt [Member] Gain on sale of real estate, net Net income attributable to noncontrolling interests Assets held for sale, net Assets Held-for-sale, Not Part of Disposal Group Long-term debt Disposal Group, Including Discontinued Operation, Noncurrent Liabilities Disposal Group, Including Discontinued Operation, Noncurrent Liabilities Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Statement [Line Items] Statement [Line Items] CPA®:18 – Global stockholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, par value (usd per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (shares) Preferred Stock, Shares Issued Common stock, par value (usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (shares) Common Stock, Shares Authorized Common stock, shares outstanding (shares) Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] 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 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] 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] Liabilities Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Debt, net Debt Instrument, Fair Value Disclosure Notes receivable Notes Receivable, Fair Value Disclosure Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Total cash and cash equivalents and restricted cash Schedule of Real Estate Properties [Table] Schedule of Real Estate Properties [Table] Currency [Axis] Currency [Axis] All Currencies [Domain] All Currencies [Domain] Euro Euro Member Countries, Euro NOK Norway, Krone GBP United Kingdom, Pounds Real Estate Property Ownership [Axis] Real Estate Property Ownership [Axis] Real Estate Properties [Domain] Real Estate Properties [Domain] Real Estate Real Estate [Member] Operating Real Estate Operating Real Estate [Member] Assets or investments located within Operating real estate on the consolidated balance sheet. Build To Suit Projects New Build To Suit Projects [Member] New Build To Suit Projects [Member] Equity method investments Equity Method Investments [Member] Two Student Housing Operating Properties Two Student Housing Operating Properties [Member] Two Student Housing Operating Properties [Member] Residential Property Multi-Family Residential Property [Member] Multi-Family Residential Property [Member] Student Housing In Pamplona, Spain Student Housing In Pamplona, Spain [Member] Student Housing In Pamplona, Spain [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Self Storage Self Storage [Member] Self Storage Multi-Family Multifamily [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecasted Scenario, Forecast [Member] Funding Axis [Axis] Funding [Axis] Funding Axis Funding Axis [Domain] Funding Axis [Domain] [Domain] for Funding Axis [Axis] Initial Funding Initial Funding [Member] Initial Funding [Member] Noncash investing Noncash [Member] Noncash [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Real Estate Properties Real Estate Properties [Line Items] Increase (decrease) in foreign currency exchange rate Increase (Decrease) In Foreign Currency Exchange Rate Increase (Decrease) In Foreign Currency Exchange Rate Foreign currency exchange rate Foreign Currency Exchange Rate, Translation Acquisition Acqusition [Abstract] -- None. No documentation exists for this element. -- Depreciation expense Depreciation Disopsal of real estate Other Real Estate, Disposals Number of properties under operating lease Operating Lease Right Of Use Assets, Count Operating Lease Right Of Use Assets, Count Operating lease remaining term Lessee, Operating Lease, Remaining Lease Term Lessee, Operating Lease, Remaining Lease Term Operating reimbursements Operating Lease, Reimbursable Rent Operating Lease, Reimbursable Rent Operating lease payments Operating Lease, Payments Operating lease future payment, year one Operating Leases, Future Minimum Payments Due, Next Twelve Months Operating lease future payment, year two Operating Leases, Future Minimum Payments, Due in Two Years Operating lease future payment, year three Operating Leases, Future Minimum Payments, Due in Three Years Operating lease future payment, year four Operating Leases, Future Minimum Payments, Due in Four Years Operating lease future payment, year five Operating Leases, Future Minimum Payments, Due in Five Years Operating lease future payment, subsequent to year five Operating Leases, Future Minimum Payments, Due Thereafter Lease revenues — operating real estate Real Estate Revenue, Other Real Estate Revenue, Other Change in real estate Other Real Estate, Period Increase (Decrease) Investment purchase price Investment Purchase Price The total cost to acquire investments. In instances where the acquired investment is categorized as a business combination the investment price excludes fees and expenses related to the acquisition, whereas when the investment is categorized as an real estate acquisition the acquisition fees are capitalized. Capitalized funds Funds Capitalized For Construction In Progress Construction costs capitalized to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Accrued liabilities Accrued Liabilities Capitalized interest Interest Costs Capitalized Placed into service Construction In Progress Placed Into Service Amount of assets under construction that are now placed into service as the balance sheet date. Properties placed into service, count Construction In Progress Placed Into Service, Count Construction In Progress Placed Into Service, Count Number of BTS projects Number Of Construction Projects During Period The number of construction projects currently in progress. Unfunded commitment Unfunded Commitment Amount of commitment unfunded as of the balance sheet date. Equity method investments ownership (percent) Equity Method Investment, Ownership Percentage Equity method investment counterparty ownership percentage Equity Method Investment, Counterparty Ownership Percentage Equity Method Investment, Counterparty Ownership Percentage Equity investment in real estate Equity Method Investments Equity method investment, liabilities Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities Basic and Diluted Loss Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Internally Assigned Grade 1 Internally Assigned Grade1 [Member] Internally Assigned Grade1 [Member] Internally Assigned Grade 2 Internally Assigned Grade2 [Member] Internally Assigned Grade2 [Member] Internally Assigned Grade 3 Internally Assigned Grade3 [Member] Internally Assigned Grade3 [Member] Internally Assigned Grade 4 Internally Assigned Grade4 [Member] Internally Assigned Grade4 [Member] Internally Assigned Grade 5 Internally Assigned Grade5 [Member] Internally Assigned Grade5 [Member] Financing Receivable, Recorded Investment [Line Items] Financing Receivable, Recorded Investment [Line Items] Credit Quality Of Finance Receivables Credit Quality Of Finance Receivables [Abstract] Credit Quality Of Finance Receivables Number of tenants and obligors Number of Tenants and Obligors The number of tenants occupying the real estate properties owned and the number of obligors to us as of the balance sheet date. Carrying Value Financing Receivable, Net Income Statement [Abstract] Revenues Revenues [Abstract] Lease revenues — net-leased Lease Income Other operating and interest income Interest Income, Other Revenues Revenues Operating Expenses Operating Expenses [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Property expenses Occupancy, Net Operating real estate expenses Other Cost of Operating Revenue General and administrative General and Administrative Expense Operating Expenses Operating Expenses Other Income and Expenses Nonoperating Income (Expense) [Abstract] Gain on sale of real estate, net Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes Interest expense Equity in losses of equity method investment in real estate Income (Loss) from Equity Method Investments Other gains and (losses) Other Nonoperating Income (Expense) Other Income and Expenses Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest (Provision for) benefit from income taxes Income Tax Expense (Benefit) Net Income Net income attributable to noncontrolling interests (inclusive of Available Cash Distributions to a related party of $1,848 and $1,905, respectively) Net Income Attributable to CPA:18 – Global Basic and diluted weighted-average shares outstanding (shares) Schedule of Related Party Transactions Schedule of Related Party Transactions [Table Text Block] Finance Receivables Financing Receivables [Text Block] Schedule of Real Estate Properties Schedule of Real Estate Properties [Table Text Block] Operating Lease Income Operating Lease, Lease Income [Table Text Block] Scheduled Future Lease Payments Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block] Scheduled Future Lease Payments - Before Adoption Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Lease Cost Lease, Cost [Table Text Block] Supplemental Balance Sheet Assets And Liabilities, Lessee [Table Text Block] Assets And Liabilities, Lessee [Table Text Block] Undiscounted Cash Flows Lessee, Operating Lease, Liability, Maturity [Table Text Block] Real Estate Under Construction Other Real Estate, Roll Forward [Table Text Block] Schedule of Assets-held for Sale Disclosure of Long Lived Assets Held-for-sale [Table Text Block] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Basis of Consolidation Consolidation, Policy [Policy Text Block] Variable Interest Entity Consolidation, Variable Interest Entity, Policy [Policy Text Block] Reclassifications Reclassification, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Intangible Assets and Liabilities Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Fair Value Measurements Fair Value of Financial Instruments, Policy [Policy Text Block] Derivatives Derivatives, Policy [Policy Text Block] Long-term Debt, Fiscal Year Maturity Long-term Debt, Fiscal Year Maturity [Abstract] 2019 (remainder) Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 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 Thereafter through 2039 Long-term Debt, Maturities, Repayments of Principal after Year Five Long term debt gross Long-term Debt, Gross Unamortized deferred financing costs Debt Issuance Costs, Net Unamortized premium, net Debt Instrument, Unamortized Discount (Premium), Net Debt, net Long-term Debt Intangible Assets And Liabilities [Abstract] Intangible Assets And Liabilities [Abstract] Schedule Of Acquired Finite Lived Intangible Asset Liability By Major Class [Table] Schedule Of Acquired Finite Lived Intangible Asset Liability By Major Class [Table] -- None. No documentation exists for this element. -- 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] In-place lease Leases, Acquired-in-Place [Member] Below-market ground lease Below Market Ground Lease [Member] Intangible asset related to an area of land subject to a ground lease. Above-market rent Above Market Leases [Member] Finite-Lived Intangible Liabilities By Major Class [Axis] [Axis] Finite-Lived Intangible Liabilities By Major Class [Axis] [Axis] -- None. No documentation exists for this element. -- Finite-Lived Intangible Liabilities, Major Class Name [Domain] Finite-Lived Intangible Liabilities, Major Class Name [Domain] -- None. No documentation exists for this element. -- Below-market rent Below Market Rent [Member] Below Market Rent [Member] Above-market ground lease Above Market Ground Lease [Member] Intangible liability related to an area of land subject to a ground lease. Finite Lived Intangible Assets Liabilities [Line Items] Intangible Assets Liabilities [Line Items] Intangible Assets Liabilities [Line Items] Finite-lived intangible asset, useful life Finite-Lived Intangible Asset, Useful Life Amortizable Intangible Assets Finite-Lived Intangible Assets, Net [Abstract] Finite-lived intangible assets, gross Finite-Lived Intangible Assets, Gross Less: accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Finite-lived intangible assets, net Finite-Lived Intangible Assets, Net Goodwill Goodwill Total intangible assets, gross Intangible Assets, Gross (Including Goodwill) Intangible Assets, Gross (Including Goodwill) Total intangible assets, net Intangible Assets, Net (Including Goodwill) Amortizable Intangible Liability Finite Lived Intangible Liabilities Net [Abstract] Finite Lived Intangible Liabilities Net Finite-Lived Intangible Liabilities, Gross Finite-Lived Intangible Liabilities, Gross Amount before amortization of liabilities, excluding financial liabilities, lacking physical substance with a finite life. Finite Lived Intangible Liabilities Accumulated Amortization Finite Lived Intangible Liabilities Accumulated Amortization Accumulated amount of amortization of liabilities, excluding financial liabilities, lacking physical substance with a finite life. Finite Lived Intangible Liabilities Net Finite Lived Intangible Liabilities Net Amount after amortization of liabilities, excluding financial liabilities and goodwill, lacking physical substance with a finite life. Agreements and Transactions with Related Parties Related Party Transactions Disclosure [Text Block] Notes receivable (Note 5) Accounts receivable, net Accounts Receivable, Net Goodwill (Note 6) Equity investment in real estate (Note 4) Prepaid expenses Prepaid Expense Other assets Other Assets Accounts receivable and other assets, net Accounts Receivable and Other Assets Accounts Receivable and Other Assets Investments in real estate: Real Estate Investment Property, Net [Abstract] Land Land Buildings and improvements Investment Building and Building Improvements Less: Accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Net investments in real estate Real Estate Investment Property, Net Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Derivatives Designated as Hedging Instruments Designated as Hedging Instrument [Member] Derivatives Not Designated as Hedging Instruments Not Designated as Hedging Instrument [Member] Derivatives, Fair Value Derivatives, Fair Value [Line Items] Derivative asset fair value Derivative Asset, Fair Value, Gross Asset Derivative liability, fair value Derivative Asset, Fair Value, Gross Liability Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] 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] Variable Interest Entity Variable Interest Entity [Line Items] Variable interest entities, count Variable Interest Entities, Count The number of variable interest entities held by the company as of the balance sheet date. Variable interest entities consolidated, count Variable Interest Entities Consolidated, Count The number of variable interest entities held by the company as of the balance sheet date which are consolidated. Variable interest entities unconsolidated, count Variable Interest Entities Unconsolidated, Count The number of variable interest entities held by the company as of the balance sheet date which are unconsolidated. Cumulative-effect adjustment for the adoption of new accounting pronouncements Cumulative Effect of New Accounting Principle in Period of Adoption Operating lease, right of use asset Operating Lease, Right-of-Use Asset Operating lease liabilities — ground leases Operating Lease, Liability Reclassification of below market intangible assets, above market intangible liabilities, prepaid rent and deferred rent Below Market Intangible Assets, Above Market Intangible Liabilities, Prepaid Rent and Deferred Rent Below Market Intangible Assets, Above Market Intangible Liabilities, Prepaid Rent and Deferred Rent Operating Lease Liabilities, Payments Due Operating Lease Liabilities, Payments Due [Abstract] 2019 (remainder) 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 Total lease payments Lessee, Operating Lease, Liability, Payments, Due Less: amount of lease payments representing interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Present value of future lease payments/lease obligations Operating real estate — Land, buildings and improvements Real Estate, Other [Member] In-place lease intangible assets In-place Lease and Other Intangible Assets [Member] In-place Lease and Other Intangible Assets [Member] Accumulated depreciation and amortization Accumulated Depreciation and Amortization [Member] Accumulated Depreciation and Amortization [Member] Assets held for sale, net Assets Held for Sale [Member] Assets Held for Sale [Member] Non-recourse mortgages, net, including debt attributable to Assets held for sale Assets held for sale, not included in discontinued operations Disposal Group, Held-for-sale, Not Discontinued Operations [Member] Subsequent Event [Table] Subsequent Event [Table] Subsequent Events Subsequent Event [Line Items] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] VIE Variable Interest Entity, Primary Beneficiary [Member] Assets Assets [Abstract] Real estate — Land, buildings and improvements Rental Properties Operating real estate — Land, buildings and improvements Real Estate Investments, Other Real estate under construction Construction in Progress, Gross In-place lease intangible assets Finite Lived Intangible Asset Acquired In Place Leases Gross This element represents the amount of value that was allocated by a lessor (acquirer) to lease agreements which exist at acquisition of a leased property, before accumulated amortization at the balance sheet date. Such amount may include the value assigned to existing tenant relationships and excludes the market adjustment component of the value assigned for above or below-market leases acquired. Right-of-use and other intangible assets Right of Use Asset And Other Intangible Assets Right of Use Asset And Other Intangible Assets Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, Equipment, and Intangible Assets Accumulated Depreciation, Depletion and Amortization, Property, Plant, Equipment, and Intangible Assets Cash and cash equivalents Accounts receivable and other assets, net Total assets Assets Liabilities Liabilities [Abstract] Non-recourse mortgages, net, including debt attributable to Assets held for sale (Note 4) Secured Debt Bonds payable, net Notes Payable Accounts payable, accrued expenses and other liabilities Accounts Payable, Accrued Expenses and Other Liabilities Accounts Payable, Accrued Expenses and Other Liabilities Total liabilities Liabilities Document and Entity Information [Abstract] Document And Entity Information. Document Information [Table] Document Information [Table] Document Information [Line Items] Document Information [Line Items] Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Central Index Key Entity Central Index Key Entity Filer Category Entity Filer Category Entity Registrant Name Entity Registrant Name Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Risk Management and Use of Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Lessor, Operating Lease, Payments, Fiscal Year Maturity Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract] 2019 (remainder) 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 Total Lessor, Operating Lease, Payments to be Received Results of Operations For Properties Sold, or Classified as Held for Sale Disposal Groups, Including Discontinued Operations [Table Text Block] Other gains and (losses) Amount of Gain (Loss) on Derivatives Recognized in Income Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net [Abstract] Amount of Gain (Loss) on Derivatives Recognized in Income Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Statement of Stockholders' Equity [Abstract] Statement Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Statements of Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Derivatives in Cash Flow Hedging Relationships Foreign currency forward contracts and collars Foreign Exchange Forward [Member] Derivative Number of Instruments Derivative, Number of Instruments Held Notional Amount Derivative, Notional Amount Fair value Foreign Currency Cash Flow Hedge Derivative at Fair Value, Net Intangible Assets and Liabilities Intangible Assets And Liabilities Disclosure [Text Block] The entire disclosure for all or part of the information related to intangible assets and liabilities. Future Minimum Payments Receivable Operating Leases, Future Minimum Payments Receivable [Abstract] 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 Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Corporate Corporate, Non-Segment [Member] All Other Segment Reconciling Items [Member] Self Storage Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Segment Reporting Information, Additional Information Segment Reporting Information, Additional Information [Abstract] Assets Segment Reporting Segment Reporting Disclosure [Text Block] Non recourse debt Bonds payable Bonds [Member] Fair Value Deferred financing costs Unamortized discount (premium) Schedule of Derivative Instruments in Statement of Financial Position, Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block] Derivative Instruments, Gain (Loss) Derivative Instruments, Gain (Loss) [Table Text Block] Schedule of Derivative Instruments Schedule of Derivative Instruments [Table Text Block] Real Estate Under Construction Real Estate Under Construction [Roll Forward] Real Estate Under Construction [Roll Forward] Beginning balance Foreign currency translation adjustments Foreign Currency Translation And Other Impacts on Real Estate Under Construction Other impacts on the carrying value of real estate under construction that includes but is not limited to foreign currency translation adjustments and building improvements. Placed into service Ending balance Lease Cost Lease, Cost [Abstract] Fixed lease cost Operating Lease, Cost Total lease cost Lease, Cost USD United States of America, Dollars Fair value Interest Rate Derivatives, at Fair Value, Net Net Investments in Direct Financing Leases Capital Leases Net Investment In Direct Financing Leases [Table Text Block] Tabular disclosure of the entity's net investments in direct financing leases. Future Lease Payments Sales-type and Direct Financing Leases, Lease Receivable, Maturity [Table Text Block] Future Lease Payments - Before Adoption Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block] Financing Receivable Credit Quality Indicators Financing Receivable Credit Quality Indicators [Table Text Block] Net investments in direct financing leases Net investments in direct financing leases Investments in real estate Real Estate Investment Property, at Cost Liabilities and Equity Liabilities and Equity [Abstract] Debt: Due to affiliates Due to Related Parties Commitments and contingencies (Note 10) Commitments and Contingencies Preferred stock, $0.001 par value; 50,000,000 shares authorized; none issued Preferred Stock, Value, Issued Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Distributions and accumulated losses Accumulated Distributions in Excess of Net Income Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Net amortization of intangibles Net Amortization Of Intangibles The aggregate expense charged against earnings to allocate the cost of intangible assets and liabilities (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income into Income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract] Amount of Gain (Loss) on Derivatives Reclassified from Other Comprehensive Income into Income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Due to Affiliates Deferred acquisition fees, including accrued interest Offering And Offering Costs Unpaid The total start-up cost incurred in connection with the initial public offering, that is due to the advisor. Accounts payable and other Deferred Acquisition Fees Due To The Advisor Amount of deferred acquisition fees recognized, but have not yet been paid, arising from acquisitions. Asset management fees payable Asset Management Fees Due To The Advisor The amount of asset management fees payable to the advisor. Current acquisition fees Current Acquisition Fees Payable The current amount of fees due to affiliates for structuring and negotiating investments on their behalf. Due to affiliate Goodwill Goodwill [Roll Forward] Goodwill - beginning balance Foreign currency translation Goodwill, Foreign Currency Translation Gain (Loss) Goodwill - ending balance Segment Reporting Information, Profit (Loss) Segment Reporting Information, Profit (Loss) [Abstract] Revenues Operating expenses Interest expense Other income and (expenses), excluding interest expense and gain on sale of real estate, net Other Income and Expenses Excluding Interest Expense The net amount of other operating income and expenses, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operations, excluding interest expense. Net income attributable to noncontrolling interests Unallocated Corporate Overhead Selling, General and Administrative Expense Total CPA:18 – Global Stockholders Parent [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Distributions and Accumulated Losses Accumulated Distributions in Excess of Net Income [Member] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Noncontrolling Interests Noncontrolling Interest [Member] Beginning equity balance, value Beginning equity balance, shares Cumulative-effect adjustment for the adoption of new accounting pronouncements (Note 2) Shares issued, value Stock Issued During Period, Value, New Issues Shares issued, shares Stock Issued During Period, Shares, New Issues Shares issued to affiliate, value Stock Issued During Period, Value, Other Shares issued to affiliate, shares Stock Issued During Period, Shares, Other Contributions from noncontrolling interests Noncontrolling Interest, Increase from Subsidiary Equity Issuance Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Distributions declared Dividends Other comprehensive (loss) income: Unrealized loss on derivative instruments Repurchase of shares, value Stock Repurchased During Period, Value Repurchase of shares, shares Stock Repurchased During Period, Shares Ending equity balance, value Ending equity balance, shares Organization Nature of Operations [Text Block] Deferred income taxes Deferred Tax Liabilities, Gross Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Deferred revenue Contract with Customer, Liability Lease liability (Note 4) Intangible liabilities, net (Note 6) Other liabilities Other Liabilities Accounts payable, accrued expenses and other liabilities Schedule of Debt Maturities Schedule of Maturities of Long-term Debt [Table Text Block] Organization and Offering Organization [Abstract] Organization [Abstract] Organization And Offering [Table] Organization And Offering [Table] -- None. No documentation exists for this element. -- Thirteen Student Housing Developments Thirteen Student Housing Developments [Member] Thirteen Student Housing Developments [Member] Organization and Offering [Line Items] Organization and Offering [Line Items] Organization and Offering [Line Items] Public Offering Offering [Abstract] Offering [Abstract] Capital interest ownership in operating partnership Capital Interest In Operating Partnership The percentage of capital interest in the Operating Partnership by the general partner. Additional Disclosures Other Business Disclosures [Abstract] Other Business Disclosures Number of tenants Number of tenants The number of tenants occupying the real estate properties owned as of the balance sheet date. Area of real estate property (sqft) Area of Real Estate Property Proceeds from issuance of shares Proceeds from Issuance Initial Public Offering Proceeds from dividend reinvestment plan Proceeds from Issuance of Common Stock, Dividend Reinvestment Plan Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Gains and Losses on Derivative Instruments Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Foreign Currency Translation Adjustments Accumulated Foreign Currency Adjustment Attributable to Parent [Member] AOCI Including Portion Attributable to Noncontrolling Interest AOCI Including Portion Attributable to Noncontrolling Interest [Member] Gains and (Losses) on Derivative Instruments Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member] Foreign Currency Translation Adjustments Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member] Noncontrolling Interest AOCI Attributable to Noncontrolling Interest [Member] Gains and (Losses) on Derivative Instruments Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Noncontrolling Interest [Member] Foreign Currency Translation Adjustments Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Reconciliation Of Accumulated Comprehensive Income Reconciliation Of Accumulated Comprehensive Income [Abstract] Reconciliation Of Accumulated Comprehensive Income [Abstract] Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive income (loss) to: AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Other gains and (losses) Other Income Net current-period other comprehensive loss (income) attributable to noncontrolling interests Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Distributions of available cash Distributions of Available Cash Amount of cash generated from operations, excluding capital proceeds, as reduced by operating expenses and debt service, excluding prepayments and lump-sum or "balloon" payments, that is available to distribute to the advisor. Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Asset management fees Asset Management [Member] Amounts Included in the Condensed Consolidated Statements of Income Operating expenses Available Cash Distributions Personnel and overhead reimbursements Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party Interest expense on deferred acquisition fees and external joint venture loans Interest Expense, Related Party Director compensation Share-based Compensation Operating expenses Related Parties Fees Paid And Expenses Reimbursed Included In Operating Expenses Expenses incurred during the period for related party transactions included in operating expenses. Acquisition Fees Capitalized Transaction Fees Incurred [Abstract] Transaction Fees Incurred [Abstract] Current acquisition fees Current Acquisition Fees Amount of current acquisition fees recognized in the period arising from acquisitions. Deferred acquisition fees Deferred Acquisition Fees Amount of deferred acquisition fees recognized in the period arising fom acquisitions. Capitalized personnel and overhead reimbursements Capitalized Personnel and Overhead Reimbursements Capitalized Personnel and Overhead Reimbursements Transaction fees incurred Advisor Fee Capitalized Advisor Fee Capitalized Operating ROU assets — ground leases Weighted-average remaining lease term — operating leases Operating Lease, Weighted Average Remaining Lease Term Weighted-average discount rate — operating leases (percent) Operating Lease, Weighted Average Discount Rate, Percent Goodwill Rollforward Schedule of Goodwill [Table Text Block] Schedule of Intangible Assets and Liabilities Schedule Of Intangible Assets Liabilities [Table Text Block] Tabular disclosure of intangible assets and liabilities, which may be broken down by segment or major class.