Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Income Tax Contingency [Line Items]
Income tax expense (benefit) totaled	$ 14,162,000	$ 7,023,000	$ 36,802,000	$ (21,418,000)
Effective tax benefit rate on income tax expense			33.70%	76.60%
Income tax receivables					23,500,000
Net Operating Loss For 2009 To The 2007 Tax Year [Member]
Income Tax Contingency [Line Items]
Income tax receivables					10,600,000
Low Income Housing Tax Credits For 2009 To The 2008 Tax Year [Member]
Income Tax Contingency [Line Items]
Income tax receivables					$ 10,300,000