Convertible Notes and Convertible Preferred Stock (Details Textual) (USD $) Share data in Thousands, unless otherwise specified	1 Months Ended		9 Months Ended
	Nov. 30, 2011	Mar. 31, 2011	Sep. 30, 2011	Sep. 30, 2012	Dec. 31, 2011	Nov. 02, 2011	Sep. 30, 2012 Convertible preferred stock [Member]	Dec. 31, 2011 Convertible preferred stock [Member]	Dec. 31, 2010 Convertible preferred stock [Member]	Dec. 31, 2010 Series A-2 preferred stock [Member] Convertible preferred stock [Member]	Dec. 31, 2010 Series B-2 preferred stock [Member] Convertible preferred stock [Member]	Dec. 31, 2010 Series C-2 preferred stock [Member] Convertible preferred stock [Member]	Dec. 31, 2010 Series D-2 preferred stock [Member] Convertible preferred stock [Member]
Convertible Notes and Convertible Preferred Stock [Line Items]
Preferred stock, shares authorized									28,000	246	4,169	3,659	18,000
Convertible notes outstanding				$ 0	$ 0
Convertible preferred stock outstanding							0	0
Convertible Notes and Convertible Preferred Stock (Textual) [Abstract]
Exchange ratio related to the Reverse Merger	0.413
Convertible notes issued		12,500,000	12,500,000
Convertible note offering		$ 25,000,000
Stated interest rate						0.00%