Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (6,280)	$ 2,239	$ (13,740)	$ (4,735)
Other comprehensive income (loss)
Unrealized gain (loss) on marketable securities, net of tax benefit of $60 for the three and six months ended June 30, 2017, and zero for the three and six months ended June 30, 2016, respectively	194	(344)	102	(434)
Other comprehensive income (loss)	194	(344)	102	(434)
Total comprehensive income (loss)	$ (6,086)	$ 1,895	$ (13,638)	$ (5,169)