Goodwill and Other Intangible Assets (Other Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Intangible assets net carrying value	$ 1,778	$ 1,859
Customer Related and Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,689	1,525
Accumulated amortization	(908)	(783)
Intangible assets net carrying value	781	742
Mortgage Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,986	2,009
Valuation allowance	(193)	(197)
Accumulated amortization	(796)	(695)
Intangible assets net carrying value	$ 997	$ 1,117