Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Hypothetical change in assumed asset volatility		10.00%
Warrant Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Warrant liability balance - beginning of period	$ 11,078		$ 4,446
Issuance of warrants at fair value	4		4
Change in fair value	2,190		8,822
Warrant liability balance - end of period	$ 13,272		$ 13,272