Schedule III - Real Estate and Accumulated Depreciation - Accumulated Depreciation Reconciliation (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]
Accumulated depreciation, beginning of year	$ 1,561,361	$ 1,391,368	$ 1,264,162
Depreciation of real estate	244,815	211,893	198,578
Total additions during period	244,815	211,893	198,578
Write-offs due to sale	(6,401)	(41,655)	(71,372)
Other	(1,129)	(245)	0
Total deductions during period	(7,530)	(41,900)	(71,372)
Accumulated depreciation, end of year	$ 1,798,646	$ 1,561,361	$ 1,391,368