Fair Value (Nonrecurring Fair Value Measurements) (Details) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Dec. 31, 2010
Loans Held For Sale Level 2	$ 2				$ 2
Nonaccrual Loans [Member]
Fair Value	237	[1]			237	[1]			429	[1]
Gains (Losses)	(50)	[1]	(2)	[1]	(104)	[1]	(6)	[1]
Loans Held for Sale [Member]
Fair Value	110	[1]			110	[1]			350	[1]
Gains (Losses)	(5)	[1]	(1)	[1]	(5)	[1]	(44)	[1]
Commercial Mortgage Servicing Rights [Member]
Fair Value	468	[1]			468	[1]			644	[1]
Gains (Losses)	(82)	[1]	(81)	[1]	(157)	[1]	(99)	[1]
Other Intangible Assets [Member]
Fair Value									1	[1]
Foreclosed and Other Assets [Member]
Fair Value	399	[1]			399	[1]			245	[1]
Gains (Losses)	(28)	[1]	(38)	[1]	(59)	[1]	(75)	[1]
Long-Lived Assets Held for Sale [Member]
Fair Value	10	[1]			10	[1]			25	[1]
Gains (Losses)	(2)	[1]	(4)	[1]	(4)	[1]	(20)	[1]
Equity Investments [Member]
Fair Value	1	[1],[2]			1	[1],[2]			3	[1],[2]
Gains (Losses)	(1)	[1],[2]	(3)	[1],[2]	(1)	[1],[2]	(3)	[1],[2]
Total Assets [Member]
Fair Value	1,225	[1]			1,225	[1]			1,697	[1]
Gains (Losses)	$ (168)	[1]	$ (129)	[1]	$ (330)	[1]	$ (247)	[1]

[1] All Level 3, except for $2 million included in Loans held for sale which is categorized as Level 2 as of September 30, 2011.

[2] Includes LIHTC and other equity investments.