Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	12,000,000,000	12,000,000,000
Common stock, shares issued	4,404,407	285,347
Common stock, shares outstanding	4,404,407	285,347
Preferred stock, par value	$ 0.0001
Preferred stock, shares authorized	8,000,000
Series C-1 Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	11,000	11,000
Preferred stock, shares issued	7,016	5,792
Preferred stock, shares outstanding	7,016	5,792
Preferred stock, liquidation preference	$ 7,016
Series C-2 Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	22,000
Preferred stock, shares issued	0	500
Preferred stock, shares outstanding	0	500
Series D-1 Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	0	5,134
Preferred stock, shares issued	0	4,615
Preferred stock, shares outstanding	0	4,615
Series F Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	3,250	0
Preferred stock, shares outstanding	3,250	0
Preferred stock, liquidation preference	$ 3,250