CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 61,406	$ 31,695	$ 15,497
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on investments	47	(86)	(8)
Foreign currency translation adjustments	70	(321)	(115)
Total other comprehensive income (loss), net of tax	117	(407)	(123)
Comprehensive income	$ 61,523	$ 31,288	$ 15,374