Consolidated Statements of Comprehensive Loss (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]
Net loss	$ (3,667)	$ (3,845)	$ (10,757)	$ (18,619)
Other comprehensive gain (loss):
Unrealized gain (loss) on investment securities, available-for-sale	0	0	0	3
Less: reclassification adjustment for losses realized in net loss	0	0	0	32
Comprehensive loss	$ (3,667)	$ (3,845)	$ (10,757)	$ (18,584)