Condensed Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net loss	$ (73,339,000)	$ (39,385,000)	$ (63,358,000)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities		(35,000)	34,000
Foreign currency translation	415,000	(256,000)	(23,000)
Other comprehensive income (loss)	415,000	(291,000)	11,000
Comprehensive loss	$ (72,924,000)	$ (39,676,000)	$ (63,347,000)