Loans And Allowance For Loan Losses (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial real estate loans, percentage	33.00%	36.20%
Non-accrual loans	$ 543,333,000	$ 883,021,000
Loans and leases receivable, impaired, interest lost on nonaccrual loans	30,200,000	71,300,000
Interest income recognized	22,865,000	18,364,000
Average recorded investment in impaired loans	1,193,641,000	1,208,618,000	999,200,000
Accrued interest income recognized			14,400,000
Accruing troubled debt restructuring	673,400,000	668,500,000	464,100,000
Provision for losses on loans	(320,369,000)	(418,795,000)	(1,131,274,000)
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial-type impaired loans	1,000,000
Interest Income Recorded [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized	7,700,000	19,300,000
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	41,400,000	60,700,000
With No Related Allowance Recorded [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized	0	0	0
Average recorded investment in impaired loans	$ 373,750,000	$ 484,097,000