Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements of Comprehensive Income (Loss)
Net income (loss)	$ (15,827)	$ 1,640
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale securities	(8)	(114)
Foreign currency translation	32	15
Total other comprehensive income (loss), net of tax	24	(99)
Total comprehensive income (loss)	$ (15,803)	$ 1,541