Schedule III—Real Estate and Accumulated Depreciation - Reconciliation of Real Estate and Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Real Estate
Balance at beginning of year	$ 1,919,777	$ 1,726,059	$ 1,461,197
Improvements and additions	189,395	290,813	283,836
Cost of real estate sold	(85,953)	(96,897)	(9,586)
Reimbursements and disposals	(2,243)	(198)	(9,388)
Balance at end of year	2,020,976	1,919,777	1,726,059
Reconciliation of Accumulated Depreciation
Balance at beginning of year	1,758	1,587	3,407
Additions	133	176	187
Disposals	0	(5)	(2,007)
Balance at end of year	$ 1,891	$ 1,758	$ 1,587