Net Income (Loss) Per Share (Details 1)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Potential shares of common stock excluded from diluted net ( loss) income per share
Options to purchase common shares	1,524,160	1,833,130	2,477,037
Outstanding warrants and options to purchase warrants	17,443,727	1,265,000	11,832,826
MHR note payable	8,353,518	7,447,995	6,675,512
Potential shares of common stock excluded from diluted net (loss) income per share	27,321,407	10,546,125	20,985,375