Goodwill and Other Intangible Assets (Changes in Carrying Amounts of Goodwill Attributable to Each Operating Segment) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Goodwill, beginning balance	$ 6,078
Acquired goodwill, net	349
Contingent consideration	2
Other adjustments	(1)
Goodwill, ending balance	6,428
Community Banking [Member]
Goodwill, beginning balance	4,542
Acquired goodwill, net	3
Contingent consideration	0
Other adjustments	0
Goodwill, ending balance	4,545
Residential Mortgage Banking [Member]
Goodwill, beginning balance	7
Acquired goodwill, net	0
Contingent consideration	0
Other adjustments	0
Goodwill, ending balance	7
Dealer Financial Services [Member]
Goodwill, beginning balance	111
Acquired goodwill, net	0
Contingent consideration	0
Other adjustments	0
Goodwill, ending balance	111
Specialized Lending [Member]
Goodwill, beginning balance	94
Acquired goodwill, net	0
Contingent consideration	0
Other adjustments	0
Goodwill, ending balance	94
Insurance Services [Member]
Goodwill, beginning balance	1,132
Acquired goodwill, net	346
Contingent consideration	2
Other adjustments	(1)
Goodwill, ending balance	1,479
Financial Services [Member]
Goodwill, beginning balance	192
Acquired goodwill, net	0
Contingent consideration	0
Other adjustments	0
Goodwill, ending balance	$ 192