Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 26,004	$ 20,594	$ 49,208	$ 39,306
Foreign currency translation adjustment	244	258	(127)	1,277
Comprehensive income	$ 26,248	$ 20,852	$ 49,081	$ 40,583