Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income attributable to common stockholders	$ 27,782	$ 16,878	$ 65,631	$ 62,655
Other comprehensive income:
Unrealized loss on derivatives, net of income taxes	(543)	421	(5,016)	(5,212)
Less interest expense on derivatives recognized into earnings, net of income taxes	(138)	(301)	(1,042)	(946)
Comprehensive income	$ 27,377	$ 17,600	$ 61,657	$ 58,389