Equity and Stock Based-Compensation (Details Textual) (USD $)				12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	May 09, 2009	Dec. 31, 2010 Common Stock [Member]	Dec. 31, 2009 Common Stock [Member]	Dec. 31, 2011 Preferred Stock [Member]	Dec. 31, 2008 Preferred Stock [Member]	Dec. 31, 2008 Series A Preferred Stock [Member]	Dec. 31, 2008 Series B Preferred Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchase of Common stock	3,570,082	3,570,082	5,000,000
Number of stock repurchased under the Stock Repurchase Plan				0	0	0		1,006,910	209,000
Aggregate price of repurchase stock							$ 15,800,000
Aggregate price of repurchase stock	$ 86,840,000	$ 86,840,000