Loan Servicing (Analysis of Activity in Residential Mortgage Servicing Rights) (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011		Jun. 30, 2010
Loan Servicing
Carrying value, beginning balance			$ 830		$ 832
Additions			126		122
Due to changes in valuation inputs or assumptions	(60)	(232)	(20)		(227)
Other changes	(29)	(31)	(57)	[1]	(62)	[1]
Carrying value, ending balance	$ 879	$ 665	$ 879		$ 665

[1] Represents the realization of expected net servicing cash flows, expected borrower payments and the passage of time.