CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 85,071	$ (3,465)	$ 44,869
Other comprehensive loss, net of tax
Foreign currency translation adjustment	(5,032)	(1,466)	(1,690)
Net decrease in unrealized loss on investments	395	256	836
Reclassification adjustment for realized gains on investments included in net income	(808)	0	0
Total other comprehensive loss	(5,445)	(1,210)	(854)
Total comprehensive income (loss)	$ 79,626	$ (4,675)	$ 44,015