Convertible Preferred Stock (Details) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Nov. 30, 2011	Dec. 31, 2009	May 31, 2009	Jun. 30, 2012 Common Stock [Member]	Nov. 30, 2011 Convertible preferred stock [Member]	Dec. 31, 2009 Convertible preferred stock [Member]
Convertible Preferred Stock (Textual) [Abstract]
Rate of conversion of convertible stock into common stock				2.9
Issuance cost of convertible preferred stock						$ 174,000
Conversion of convertible preferred stock into common stock	2,757,788				7,244,523
Convertible Preferred Stock (Additional Textual) [Abstract]
Cash proceeds on issuance of convertible preferred stock		75,500,000
Maximum issuable value of preferred stock			$ 146,300,000