Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income attributable to common stockholders	$ 12,727	$ 13,134
Other comprehensive income:
Unrealized loss on derivatives, net of income taxes	(764)	(5,798)
Less: Interest expense on derivatives recognized into earnings, net of income taxes	(563)	(525)
Comprehensive income	$ 12,526	$ 7,861