Loans And Allowance For Loan Losses (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial real estate loans, percentage	36.20%	38.80%
Non-accrual loans	$ 883,021,000	$ 891,622,000
Loans and leases receivable, impaired, interest lost on nonaccrual loans	71,300,000	87,100,000
Interest income recognized	18,364,000
Allowance for loan losses allocated to accuring TDRs	668,500,000	464,100,000
Average recorded investment in impaired loans	1,208,618,000	999,200,000	1,370,000,000
Accrued interest income recognized	18,400,000	14,400,000	8,900,000
Accruing troubled debt restructuring	668,500,000	464,100,000	213,600,000
Provision for losses on loans	(418,795,000)	(1,131,274,000)	(1,805,599,000)
Interest Income Recorded [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized	19,000,000	32,000,000
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loan substandard period (in days)	90
Loss And Charged Off [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retail loan charge-off period (in days)	120
Accruing TDRs With Modifications And Renewals Completed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for losses on loans	60,700,000	54,900,000
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial-type impaired loans		$ 1,000,000