Derivative Financial Instruments (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended			3 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012
Changes in derivative instrument liability
Balance at the beginning of the period				$ 1,534					$ 1,534
Change in fair value of warrants during the quarter	42	(425)	(756)	(223)	484	77	(1,803)	1,093	(1,362)	(149)	1,933
Balance at the end of the period	172				1,534				172	1,534
Derivative instrument liability | Warrants
Changes in warrants
Balance at the beginning of the period (in shares)				858,469				2,265,160	858,469	2,265,160	2,265,160				2,265,160
Warrants classified to derivative liability during the quarter (in shares)														112,500
Reclassification of derivative liability to equity during the quarter (in shares)							(1,406,691)					(112,500)
Balance at the end of the period (in shares)	858,469				858,469				858,469	858,469	2,265,160	2,265,160
Changes in derivative instrument liability
Balance at the beginning of the period				1,534				5,258	1,534	5,258	3,325				3,325
Warrants classified to derivative liability during the quarter														169
Reclassification of derivative liability to equity during the quarter							(3,575)					(169)
Change in fair value of warrants during the quarter	42	(425)	(756)	(223)	484	77	(1,803)	1,093				764	(140)	1,317	(8)
Balance at the end of the period	$ 172				$ 1,534				$ 172	$ 1,534	$ 5,258	$ 5,258