Stockholders' Equity - Convertible Preferred Stock (Details) (USD $)	Dec. 31, 2013
Series G1 Convertible Preferred Stock
Shares of Common Stock Issuable Upon Conversion	8
Conversion Price	$ 11,200	[1]
Series G2 Convertible Preferred Stock
Shares of Common Stock Issuable Upon Conversion	37
Conversion Price	$ 2,688	[1]

[1] Certain conversion prices are subject to adjustment under certain circumstances.