Stock Purchase Warrants (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Beginning Balance			$ 10,567
Change in fair value of warrant liability	$ (666)	$ (4,141)	(3,681)	$ 3,906
Ending Balance	$ 6,886	$ 10,700	$ 6,886	$ 10,700