Condensed Consolidated Statements of Comprehensive Loss (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net loss	$ (26,920)	$ (21,791)	$ (66,285)	$ (36,537)
Other comprehensive income (loss), net of tax :
Unrealized income (loss) on marketable securities, net of tax	3	(9)	(3)	(21)
Unrealized loss on cash flow hedges, net of tax	(3,060)	0	(4,272)	0
Less: reclassification adjustment for realized losses included in net loss, net of tax	642	0	1,277	0
Other comprehensive loss	(2,415)	(9)	(2,998)	(21)
Comprehensive loss	$ (29,335)	$ (21,800)	$ (69,283)	$ (36,558)