Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss	$ (50,785)	$ (45,719)	$ (62,134)
Other comprehensive (loss) income, net of tax:
Unrealized (loss) gain on available-for-sale securities	(1,429)	(1,122)	690
Adjustment for realized gain on available-for-sale securities, and included in net income	0	(2,217)	0
Foreign currency translation adjustments	(3,040)	1,595	(69)
Other comprehensive (loss) income, net	(4,469)	(1,744)	621
Total comprehensive loss	$ (55,254)	$ (47,463)	$ (61,513)