Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 19,145	$ 16,705
Other comprehensive income (loss):
Change in unrealized gain (loss) on valuation of interest rate swap agreements	1,394	(19,371)
Other comprehensive income (loss)	1,394	(19,371)
Comprehensive income (loss)	20,539	(2,666)
Net income attributable to non-controlling interests and private perpetual preferred unitholders	(9,160)	(9,277)
Other comprehensive (income) loss attributable to non-controlling interests	(658)	10,640
Comprehensive income (loss) attributable to common stockholders	$ 10,721	$ (1,303)