Consolidated Statements of Comprehensive Loss (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net loss	$ (40,426)	$ (31,390)	$ (63,900)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	3	(273)	217
Net change in unrealized gains (losses) on investments	130	0	0
Other comprehensive income (loss), net of tax	133	(273)	217
Total comprehensive loss	$ (40,293)	$ (31,663)	$ (63,683)