Stockholders' Equity (Stock and Warrant Public Offerings) (Details) (USD $)	9 Months Ended		1 Months Ended						1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	May 31, 2013 Series C Redeemable Convertible Preferred Stock [Member]	May 31, 2011 Underwritten Public Offering 2011	Sep. 16, 2013 Underwritten Public Offering 2011	May 08, 2013 Underwritten Public Offering 2011	Feb. 21, 2013 Underwritten Public Offering 2011	Mar. 29, 2012 Underwritten Public Offering 2011	Sep. 16, 2013 Underwritten Public Offering 2013	Feb. 20, 2013 Underwritten Public Offering 2013	Feb. 20, 2013 Underwritten Public Offering 2013 Warrant
Public Offering [Line Items]
Underwritten public offering of common stock and warrants				8,265,000					18,600,000	18,910,000
Number of warrants called to purchase shares of common stock				7,128,563	22,995,365	20,762,805	18,925,389	9,421,008		18,910,000	1,891,000
Number of shares of common stock purchased by the underwriter				929,813						2,836,500
Net Proceeds, after underwriting discounts and commissions and other fees payable				$ 18,289,883					$ 9,151,221	$ 1,948,766
Portion of warrants in the share and warrant combination				0.75
Fair value recorded of common stock warranty liability				$ 8,768,143
Price to public, per share and warrant combination				$ 2.42						$ 0.15
Exercise price of the warrants on issuance of common stock	0.15			3.00	0.93	1.03	1.13	2.27		0.15	0.18
Number of anti-dilutive Series C redeemable convertible preferred stock	42,755,013	11,695,791	10,431