Summary of Significant Accounting Policies (Additional Narratives) (Details) € in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 01, 2019 USD ($) $ / €	Jan. 01, 2019 EUR (€) $ / €
Summary of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Assets, Net	$ 98,537,000	$ 90,697,000
Impairment charges	0	0	$ 0
Realized gain on trading securities	1,000,000.0
Unrealized gain on securities	1,300,000
Deposits in foreign financial institutions	27,600,000
Investments in real estate-related securities	36,491,000	9,599,000
Straight-line rent receivable	8,600,000	5,800,000
Allowance for doubtful accounts		300,000
Gain on sale of real estate	0	14,491,000	0
Due to (from) related party	42,782,000	26,022,000
Right-of-use asset, net	37,606,000	0
Operating lease liability	$ 1,583,000	0	$ 0
Bishop’s Square
Summary of Significant Accounting Policies [Line Items]
Weighted average remaining lease term	763 years
Bishop’s Square | Accounting Standards Update 2016-02
Summary of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Assets, Net				$ (33,900,000)	€ (29.7)
Foreign currency exchange rate | $ / €				1.14	1.14
Right-of-use asset, net				$ 33,900,000	€ 29.7
Lodz Urban Logistics
Summary of Significant Accounting Policies [Line Items]
Operating lease liability	$ 1,583,000
Operating lease weighted average discount rate percent	5.60%
Lodz Urban Logistics | Accounting Standards Update 2016-02
Summary of Significant Accounting Policies [Line Items]
Right-of-use asset, net	$ 4,400,000
Operating lease liability	1,600,000
Distribution and Servicing Fees | Dealer Manager
Summary of Significant Accounting Policies [Line Items]
Due to (from) related party	22,479,000	8,332,000
Trading Securities
Summary of Significant Accounting Policies [Line Items]
Investment income, interest and dividend	1,000,000.0
Lodz Urban Logistics
Summary of Significant Accounting Policies [Line Items]
Rent expense	$ 24,000	$ 0