Schedule III Real Estate Investments and Accumulated Depreciation - Summary of Activity for Real Estate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate [Roll Forward]
Balance at beginning of year	$ 1,845,776	$ 1,636,930
Acquisition of properties	289,591	227,058
Disposition of properties	(41,560)	(56,985)
Construction in progress	28,154	7,434
Improvements, net of write-offs	32,233	31,339
Balance at end of year	$ 2,154,194	$ 1,845,776