Unconsolidated Real Estate Joint Ventures (Narrative) (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) properties	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($)
Income from investments in unconsolidated real estate joint venture	$ (381,000)	$ (22,000)	$ 72,000
Distributions from joint ventures	$ 112,000	567,000	442,000
Document Period End Date	Dec. 31, 2019
St. Petersburg Joint Venture [Member]
Number of unconsolidated real estate joint ventures | properties	2
Carrying Amount Joint Venture Mortgage Loan	$ 61,200,000			$ 60,000,000.0
Maximum Availability Joint Venture Mortgage Loan	$ 85,000,000.0
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	3.75%
Payments to Acquire Real Estate and Real Estate Joint Ventures		29,500,000
Equity Method Investment, Ownership Percentage	65.00%
Equity Method Investment, Partner's Ownership Percentage	35.00%
Income from investments in unconsolidated real estate joint venture	$ 140,000	52,000
Distributions from joint ventures	0
Remaining Availability Joint Venture Mortgage Loan	23,800,000
Long Term Funding Commitment For Project Development	$ 24,300,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	6.00%
Theatre Project China Member
Number of unconsolidated real estate joint ventures | properties	3
Income from investments in unconsolidated real estate joint venture	$ 241,000	74,000	72,000
Distributions from joint ventures	112,000	567,000	$ 442,000
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures	4,600,000	5,000,000.0
Experiential Lodging Properties [Member] | St. Petersburg Joint Venture [Member]
Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures	$ 29,700,000	$ 29,500,000
Interest Rate Swap [Member] | St. Petersburg Joint Venture [Member]
Derivative, Fixed Interest Rate	3.00%