Schedule III - Real Estate and Accumulated Depreciation - Reconciliation of Accumulated Depreciation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate, Accumulated Depreciation [Roll Forward]
Balance, beginning of year	$ 862,534	$ 747,304	$ 656,900
Depreciation expense	158,605	146,207	130,069
Disposals	(79,527)	(30,977)	(39,665)
Balance, end of year	$ 941,612	$ 862,534	$ 747,304