Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (10,232)	$ (16,730)	$ (16,833)	$ (15,824)
Change in unrealized gains and losses related to cash flow hedges:
Loss recognized in accumulated other comprehensive loss, net	(71)	(1,455)	(145)	(1,051)
Loss reclassified from accumulated other comprehensive loss, net to the statement of operations	355	22	686	45
Change in unrealized gains and losses related to available-for-sale investments:
Gain recognized in accumulated other comprehensive loss, net	274	1	821	143
Gain reclassified from accumulated other comprehensive loss, net to the statement of operations	(9)	(3)	(10)	(3)
Other comprehensive income (loss), before tax	549	(1,435)	1,352	(866)
Income tax benefit (expense) related to items of accumulated other comprehensive loss, net	(202)	(375)	(497)	100
Comprehensive loss	$ (9,885)	$ (18,540)	$ (15,978)	$ (16,590)