Subsequent Events (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007	Dec. 31, 2006	Dec. 31, 2005	Dec. 31, 2004
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	2,136,000	1,190,500	861,000	938,290	837,500	665,500	668,085	761,451	363,835
Share-Based Compensation Arrangements By Share-Based Payment Award, Options, Grants In Period, Weighted Average Exercise Price	$ 3.26	$ 6.91	$ 3.10	$ 1.99	$ 6.11	$ 5.72	$ 3.61	$ 2.66	$ 0.56
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Weighted Average Grant Date Fair Value	$ 2.21	$ 4.60	$ 2.24
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	785,500
Share-Based Compensation Arrangements By Share-Based Payment Award, Options, Grants In Period, Weighted Average Exercise Price	$ 0.93
Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Grants In Period, Weighted Average Grant Date Fair Value	$ 0.71