Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (7,566)	$ 520	$ (18,792)	$ (8,638)
Other comprehensive gain (loss), net of tax
Unrealized gain (loss) on marketable securities	62	(119)	332	(78)
Comprehensive income (loss)	$ (7,504)	$ 401	$ (18,460)	$ (8,716)