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)	$ 2,239	$ (5,360)	$ (4,735)	$ (10,922)
Other comprehensive income (loss)
Unrealized gain (loss) on marketable securities, net of tax benefit of zero for the three months and six months ended June 30, 2016, and $454 and $463 for the three months and six months ended June 30, 2015, respectively	(344)	776	(434)	792
Other comprehensive income (loss)	(344)	776	(434)	792
Total comprehensive income (loss)	$ 1,895	$ (4,584)	$ (5,169)	$ (10,130)