Schedule III Real Estate and Accumulated Depreciation - Changes in Total Real Estate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Carrying amount of real estate investments
Gross real estate, beginning balance	$ 5,273,477	$ 4,915,813	$ 4,685,336
Acquisitions	250,843	265,129	142,255
Improvements	257,993	181,622	126,279
Properties held for sale	0	(49,973)	0
Dispositions and other	(39,264)	(39,114)	(38,057)
Gross real estate, ending balance	$ 5,743,049	$ 5,273,477	$ 4,915,813