Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Comprehensive income
Net income	$ 80,052	$ 61,051	$ 51,537
Other comprehensive loss
Foreign currency translation adjustment	(73)	(53)
Comprehensive income	$ 79,979	$ 60,998	$ 51,537