Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 84,290	$ 117,253	$ 118,253
Other comprehensive loss:
Unrealized loss on valuation of interest rate swap agreements	(21,813)	(2,721)	(11,658)
Amount reclassified into interest expense	1,231	1,845	1,142
Other comprehensive loss	(20,582)	(876)	(10,516)
Comprehensive income	63,708	116,377	107,737
Net income attributable to non-controlling interests and private perpetual preferred unitholders	(34,845)	(51,650)	(55,606)
Other comprehensive loss attributable to non-controlling interests	8,254	382	4,901
Comprehensive income attributable to common stockholders	$ 37,117	$ 65,109	$ 57,032