Earnings per Share (Details 1)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Common Stock issuable upon the exercise of certain stock options
Common stock that have been excluded from the diluted shares calculation	2,676,877	7,111,317	2,676,877	7,111,317
Stock options outstanding under the 1993,1997, 2006 and 2011 Stock Option Plans [Member]
Common Stock issuable upon the exercise of certain stock options
Common stock that have been excluded from the diluted shares calculation	584,586	2,826,933	584,586	2,862,933
Series C Convertible Preferred Stock [Member]
Common Stock issuable upon the exercise of certain stock options
Common stock that have been excluded from the diluted shares calculation	2,092,291	4,284,384	2,092,291	4,284,384