Loans And Leases (Schedule Of Activity In The Allowance For Loan Losses) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 22	$ 100
Charge-offs	0	(19)
Provisions	0	(1)
Ending balance	22	80
Institutional [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	22	31
Charge-offs	0	0
Provisions	0	0
Ending balance	22	31
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance		69
Charge-offs		(19)
Provisions		(1)
Ending balance	$ 0	$ 49