Stock Awards (Details 1) (USD $)	9 Months Ended
	Sep. 30, 2012
Summary of the restricted stock activity
Number of Shares, Early exercised	5,523,840
Number of Shares, Outstanding at September 30, 2012	1,134,851
Restricted stock [Member]
Summary of the restricted stock activity
Number of Shares, Outstanding at December 31, 2011	578,616
Number of Shares, Early exercised	263,970
Number of Shares, Vested	(491,337)
Number of Shares, Repurchased	(2,084)
Number of Shares, Outstanding at September 30, 2012	349,165
Weighted-Average Grant Date Fair Value, Outstanding at December 31, 2011	1.21
Weighted-Average Grant Date Fair Value, Early exercised	2.38
Weighted-Average Grant Date Fair Value, Vested	1.50
Weighted-Average Grant Date Fair Value, Repurchased	0.11
Weighted-Average Grant Date Fair Value, Outstanding at September 30, 2012	1.69