Loans And Leases (Financing Receivables On Non-Accrual Status) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, recorded investment on non-accrual status	$ 5	$ 158
Property Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, recorded investment on non-accrual status		79
Property Development Acquired-Credit Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, recorded investment on non-accrual status		42
Other Acquired Credit-Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, recorded investment on non-accrual status	5	22
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, recorded investment on non-accrual status		$ 15