Stock-Based Compensation (Details 6) (USD $) In Thousands, unless otherwise specified	0 Months Ended	12 Months Ended
	Apr. 06, 2011	Dec. 31, 2012	Dec. 31, 2011
Balance at December 31, 2010		$ 0	$ 0
Warrant liability	716	0	1,492
Change in fair value of warrant liability		0	242
Reclassification of warrant liability to additional paid-in capital		0	(1,734)
Balance at December 31, 2011		$ 0	$ 0