Real Estate and Accumulated Depreciation - Schedule III (Changes in Accumulated Depreciation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real estate investments, at cost:
Balance at beginning of year	$ 2,296,627	$ 2,229,374	$ 2,060,458
Additions-Acquisitions	80,980	121,244	169,741
Disposals	(166,156)	(53,991)	(825)
Balance at end of the year	2,211,451	2,296,627	2,229,374
Accumulated depreciation:
Balance at beginning of year	226,167	170,271	119,014
Depreciation expense	64,731	62,595	51,268
Disposals	(30,499)	(6,699)	(11)
Balance at end of the year	$ 260,399	$ 226,167	$ 170,271