Schedule III Real Estate and Accumulated Depreciation (Schedule of Changes in Rental Properties and Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real Estate and Accumulated Depreciation [Line Items]
Balance	$ 257,199	$ 241,128	$ 143,384
Additions	1,504	38,198	134,709
Disposals	(7,843)	(22,220)	(34,814)
Impairment recovery (loss), net		93	(2,151)
Balance	250,860	257,199	241,128
Balance	22,929	21,548	28,513
Depreciation for the period	9,563	9,475	6,898
Depreciation on assets sold or disposed	(3,615)	(8,094)	(13,863)
Balance	28,877	$ 22,929	$ 21,548
Aggregate cost of land, buildings, furniture and equipment for Federal income tax purposes	$ 253,000
Minimum [Member] | Building And Improvements [Member]
Real Estate and Accumulated Depreciation [Line Items]
Useful life used for computation of depreciation	15 years
Minimum [Member] | Furniture And Equipment [Member]
Real Estate and Accumulated Depreciation [Line Items]
Useful life used for computation of depreciation	3 years
Maximum [Member] | Building And Improvements [Member]
Real Estate and Accumulated Depreciation [Line Items]
Useful life used for computation of depreciation	40 years
Maximum [Member] | Furniture And Equipment [Member]
Real Estate and Accumulated Depreciation [Line Items]
Useful life used for computation of depreciation	12 years