Real Estate (Summary of Income (loss) from Discontinued Operations) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
REVENUES
Rental revenues	$ 45,073,000	$ 87,839,000	$ 88,763,000
Other	184,000	524,000	885,000
Total revenues	45,257,000	88,363,000	89,648,000
EXPENSES
Operating, maintenance and management	10,818,000	19,518,000	21,311,000
Real estate and other property-related taxes	6,749,000	13,040,000	12,727,000
General and administrative	151,000	222,000	174,000
Depreciation and amortization	9,726,000	27,313,000	31,943,000
Total expenses	27,444,000	60,093,000	66,155,000
OPERATING INCOME	17,813,000	28,270,000	23,493,000
NON-OPERATING INCOME AND EXPENSES
Interest expense	(3,511,000)	(4,735,000)	(2,134,000)
Total non-operating income and expenses	(3,511,000)	(4,735,000)	(2,134,000)
INCOME FROM DISCONTINUED OPERATIONS	14,302,000	23,535,000	21,359,000
Impairment (charges) reversal	(16,629,000)	(33,913,000)	643,000
Gain on sales	125,500,000	1,047,000
Total income (loss) from discontinued operations	$ 123,173,000	$ (9,331,000)	$ 22,002,000