Schedule III: Real Estate and Accumulated Depreciation (Rollforward of Real Estate and Accumulated Deprecation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
REAL ESTATE:
Balance at beginning of period	$ 1,069,426	$ 1,071,043	$ 1,041,342
Changes during the period	1,084,621	1,075,054	1,071,919
Less: Fully depreciated assets	(23)	(5,628)	(876)
Balance at end of the period	1,084,598	1,069,426	1,071,043
ACCUMULATED DEPRECIATION:
Balance at beginning of period	370,557	350,122	324,499
Additions charged to operating expenses	25,734	26,063	26,499
Subtotal of accumulated depreciation	396,291	376,185	350,998
Less: Fully depreciated assets	(23)	(5,628)	(876)
Balance at end of the period	396,268	370,557	350,122
Land
REAL ESTATE:
Changes during the period	0	(11,921)	0
Buildings and leasehold improvements
REAL ESTATE:
Changes during the period	15,002	5,842	31,134
Development and construction in progress
REAL ESTATE:
Changes during the period	$ 193	$ 10,090	$ (557)