Goodwill And Other Intangible Assets (Gross Carrying Amount, Accumulated Amortization And Net Carrying Amount Of Other Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
Goodwill [Line Items]
Gross Carrying Amount	$ 3,339	$ 3,304
Accumulated Amortization	(896)	(845)
Net Carrying Amount	2,443	2,459	2,644	2,593
Customer Relationships [Member]
Goodwill [Line Items]
Gross Carrying Amount	2,404	2,369
Accumulated Amortization	(682)	(641)
Net Carrying Amount	1,722	1,728
Core Deposits Intangibles [Member]
Goodwill [Line Items]
Gross Carrying Amount	709	702
Accumulated Amortization	(127)	(117)
Net Carrying Amount	582	585
Other Intangible Assets [Member]
Goodwill [Line Items]
Gross Carrying Amount	226	233
Accumulated Amortization	(87)	(87)
Net Carrying Amount	$ 139	$ 146