Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 40,470	$ 45,709	$ 43,397
Other comprehensive income (loss):
Foreign currency translation adjustment	55	(82)	(37)
Tax benefit (provision)	(20)	11	6
Comprehensive income	$ 40,505	$ 45,638	$ 43,366