Schedule III - Real Estate Investments - Summary of Historical Cost and Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property
Balance, beginning of period	$ 3,230,428	$ 2,812,856	$ 2,357,322
Disposals	(7,821)	(41,363)	(43,616)
Additions (acquisitions and improvements)	810,527	458,935	499,150
Balance, end of period	4,033,134	3,230,428	2,812,856
Accumulated depreciation
Balance, beginning of period	(558,560)	(467,644)	(394,823)
Disposals	6,577	28,172	30,139
Additions (depreciation and amortization expense)	(150,961)	(119,088)	(102,960)
Balance, end of period	$ (702,944)	$ (558,560)	$ (467,644)