Stock Purchase Warrants (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Beginning Balance			$ 6,756
Change in fair value of warrant liability	$ (4,141)	$ 0	3,906	$ 0
Ending Balance	$ 10,662		$ 10,662