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 Income And Comprehensive Income [Abstract]
Net loss	$ (43,413)	$ (89,266)	$ (24,892)
Unrealized gain (loss) on cash equivalents and marketable securities, net of tax	(9)	22	(29)
Total comprehensive loss	$ (43,422)	$ (89,244)	$ (24,921)