Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	18,244,009	15,225,980
Common stock, shares outstanding	18,244,009	15,225,980
Preferred stock, par value (usd per share)	$ 0.0001
Preferred stock, shares authorized	8,000,000
Series C-1 Convertible Preferred Stock [Member]
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	11,000	11,000
Preferred stock, shares issued	3,906	3,917
Preferred stock, shares outstanding	3,906	3,917
Liquidation preference	$ 3,906	$ 3,917
Series F Convertible Preferred Stock [Member]
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	2,737	2,798
Preferred stock, shares outstanding	2,737	2,798
Liquidation preference	$ 2,737	$ 2,798