Loans and Leases (Schedule Of Allowance For Loan Losses) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, Individually evaluated for impairment	$ 390		$ 422
Loans and leases, Collectively evaluated for impairment	13,595	[1]	11,885	[1]
Total loans and leases	13,985		12,307
Institutional
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, Individually evaluated for impairment	10		11
Loans and leases, Collectively evaluated for impairment	13,566	[1]	11,885	[1]
Total loans and leases	13,576		11,896
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, Individually evaluated for impairment	380		411
Loans and leases, Collectively evaluated for impairment	29	[1]	0	[1]
Total loans and leases	$ 409		$ 411

[1] As of both March 31, 2013 and December 31, 2012, the entire $22 million allowance for loan losses was related to institutional loans collectively evaluated for impairment.