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)	$ (1,308)	$ 6,221	$ 14,503	$ 7,761
Other comprehensive income (loss), net of tax
Unrealized gains on investments		3	37	20
Foreign currency translation adjustments	27	43	(109)	1
Total other comprehensive income (loss), net of tax	27	46	(72)	21
Comprehensive income (loss)	$ (1,281)	$ 6,267	$ 14,431	$ 7,782