Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets
Patents, accumulated amortization (in dollars)	$ 2,695	$ 267
Stockholders' equity
Series I redeemable preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Series I redeemable preferred stock, shares issued	119,760	119,760
Series I redeemable preferred stock, shares outstanding	119,760	119,760
Series I redeemable preferred stock, liquidation preference	$ 167	$ 167
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	5,000,000	5,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	50,000,000
Common stock, shares issued	8,206,335	3,770,113
Common stock, shares outstanding	8,206,335	3,769,712
Treasury stock, shares	228	401
Series A Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares authorized	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
liquidation preference	$ 0.0001	$ 0.0001
Series B Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	1	1
Preferred stock, shares outstanding	1	1
liquidation preference	$ 0.0001	$ 0.0001
Series C Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	1	1
Preferred stock, shares outstanding	1	1
liquidation preference	$ 0.0001	$ 0.0001
Series D Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	18,000	1,227,582
Preferred stock, shares outstanding	18,000	1,227,582
liquidation preference	$ 0.0001	$ 0.0001
Series D-1 Preferred [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	945,139	59,265
Preferred stock, shares outstanding	945,139	59,265
liquidation preference	$ 0.0001	$ 0.0001
Series E Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
liquidation preference	$ 0.0001	$ 0.0001
Series F Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
liquidation preference	$ 0.0001	$ 0.0001
Series F-1 Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	156,250	156,250
Preferred stock, shares outstanding	156,250	156,250
liquidation preference	$ 0.0001	$ 0.0001
Series H Convertible Preferred Stock [Member]
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.0001
Preferred stock, shares issued	459,043	459,043
Preferred stock, shares outstanding	459,043	459,043
liquidation preference	$ 0.0001	$ 0.0001