Stockholders' Equity (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock option activity
Stock option activity, Shares, Beginning Balance	818,028	908,028	1,258,028
Stock option activity, Granted
Stock option activity, Expired	(235,000)	(90,000)	(350,000)
Stock options exercised	(150,000)
Stock option activity, Shares, Ending Balance	433,028	818,028	908,028
Stock option activity, Lower limit, Outstanding Price per Share, Beginning Balance	$ 1.59	$ 1.59	$ 1.59
Stock option activity, Upper limit, Outstanding Price per Share, Beginning Balance	$ 6.70	$ 13.10	$ 13.10
Stock option activity, Upper limit, Granted Price per Share
Stock option activity, Lower limit, Exercised Price per Share	$ 1.59
Stock option activity, Upper limit, Expired Price per Share	$ 6.70	$ 13.10	$ 9.78
Stock option activity, Lower limit, Outstanding Price per Share, Ending Balance	$ 2.30	$ 1.59	$ 1.59
Stock option activity, Upper limit, Outstanding Price per Share, Ending Balance	$ 5.85	$ 6.70	$ 13.10
Weighted-Average Exercise Price, Outstanding, Beginning Balance	$ 4.19	$ 5.07	$ 6.38
Weighted-Average Exercise Price, Granted
Weighted-Average Exercise Price, Expired	$ 6.70	$ 13.10	$ 9.78
Weighted-Average Exercise Price, Outstanding, Ending Balance	$ 3.72	$ 4.19	$ 5.07