Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 47,565	$ 21,163	$ 41,419	$ 107,550	$ 98,826
Other comprehensive income (loss), net of tax:
Amortization of loss on cash flow hedge	215		215	646	646
Foreign currency translation adjustment	137		(951)	1,036	(2,223)
Other comprehensive income (loss), net of tax	352		(736)	1,682	(1,577)
Comprehensive income	$ 47,917		$ 40,683	$ 109,232	$ 97,249