Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies [Abstract]

Securities excluded from calculation of weighted-average shares outstanding

	For the year ended December 31,
	2012		2011
Shares of convertible preferred stock		—		7,282,000
Shares underlying options outstanding		14,050,625		13,608,500
Shares underlying warrants outstanding		153,299,031		49,135,602