Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net loss	$ (68,512)	$ (50,785)	$ (45,719)
Other comprehensive income (loss):
Unrealized gain (loss) on available-for-sale securities, net of income tax of $2.2 million, $0, and $0, respectively	4,185	(1,429)	(1,122)
Foreign currency translation adjustments	(445)	(3,040)	1,595
Adjustment for realized gain on available-for-sale securities, and included in net income	0	0	(2,217)
Other comprehensive income (loss)	3,740	(4,469)	(1,744)
Total comprehensive loss	$ (64,772)	$ (55,254)	$ (47,463)