Schedule III: Real Estate and Accumulated Depreciation - Rollforward of Real Estate and Accumulated Deprecation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
REAL ESTATE:
Balance at beginning of period	$ 1,084,598	$ 1,069,426	$ 1,071,043
Changes during the period	1,088,903	1,084,621	1,086,975
Assets sold	(14,186)	0	(11,921)
Assets written-off	(8,097)	(23)	(5,628)
Balance at end of period	1,066,620	1,084,598	1,069,426
ACCUMULATED DEPRECIATION:
Balance at beginning of period	396,268	370,557	350,122
Depreciation expense	28,137	25,734	26,063
Subtotal of accumulated depreciation	424,405	396,291	376,185
Accumulated depreciation on assets sold	(405)	0	0
Accumulated depreciation on assets written-off	(8,097)	(23)	(5,628)
Balance at end of period	415,903	396,268	370,557
Land
REAL ESTATE:
Changes during the period	0	0	0
Buildings and leasehold improvements
REAL ESTATE:
Changes during the period	2,959	15,002	5,842
Development and construction in progress
REAL ESTATE:
Changes during the period	$ 1,346	$ 193	$ 10,090