Derivative Financial Instruments (Details 2) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Changes in derivative instrument liability
Balance at the beginning of the period		$ 172		$ 172
Change in fair value of warrants during the quarter	$ 1,542		$ (756)	1,810	$ (979)
Balance at the end of the period	$ 1,981			$ 1,981
Derivative instrument liability | Warrants
Changes in warrants
Balance at the beginning of the period (in shares)		858,469		858,469
Expiration of warrants ( in shares)	(324,000)
Balance at the end of the period (in shares)	534,469			534,469
Changes in derivative instrument liability
Balance at the beginning of the period		$ 172		$ 172
Change in fair value of warrants during the quarter	$ 1,542	$ 268
Expiration of warrants	(1)
Balance at the end of the period	$ 1,981			$ 1,981