Loans And Leases (Schedule Of Activity In The Allowance For Loan Losses) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	$ 100	$ 79	$ 18
Charge-offs	(78)	(4)	(91)
Provisions		25	149
Recoveries			3
Ending balance	22	100	79
Institutional [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	31
Provisions	(9)
Ending balance	22
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	69
Charge-offs	(78)
Provisions	$ 9