Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (2,336)	$ 1,398	$ (3,599)	$ 1,750
Unrealized gain (loss) on marketable securities, net of taxes of $0	(12)	(4)	28	(9)
Total comprehensive income (loss)	$ (2,348)	$ 1,394	$ (3,571)	$ 1,741