Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (24,007)	$ (20,030)
Other comprehensive gain (loss) (net of tax):
Net change in net unrealized loss on investments	169	44
Net change in unrealized gain (loss) on hedging instruments	916	(130)
Other comprehensive income (loss)	1,085	(86)
Comprehensive loss	$ (22,922)	$ (20,116)