Stock Purchase Warrants (Details Textual) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Oct. 10, 2014	Oct. 25, 2012	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair Value Adjustment of Warrants			$ 498	$ 4,152
Warrant liabilities			$ 11,065	10,900	$ 10,567
Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance Of Warrants To Purchase Of Common Stock		635,855
Warrants Exercisable Price Per Share		$ 1.60
Investment Warrants Expiration Date1		Oct. 25, 2017
Class of Warrant or Right, Outstanding			311,834
Stock Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from Issuance of Common Stock	$ 19,100
Sale of Stock, Number of Shares Issued in Transaction	14,059,616
Sale of Stock, Price Per Share	$ 1.47
Issuance Of Warrants To Purchase Of Common Stock	0.5
Share Based Compensation Arrangement By Share Based Payment Award Warrants Exercisable Number	7,029,808
Warrants Exercisable Price Per Share	$ 1.75
Fair Value Adjustment of Warrants	$ 7,400		$ 500	$ 4,200
Investment Warrants Expiration Date1	Oct. 10, 2019