Allowances for Loan and Lease Losses and Unfunded Loan Commitments and Letters of Credit (Rollforward of Allowance For Loan and Lease Losses and Associated Loan Data) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011	Dec. 31, 2011
Beginning Balance				$ 4,347	[1]	$ 4,887
Charge-offs				(1,410)		(1,782)
Recoveries				431		470
Net charge-offs				(979)		(1,312)
Provision for credit losses	228		261	669		962
Net change in allowance for unfunded loan commitments and letters of credit				1		(29)
Other				1		(1)
Ending Balance	4,039	[1]	4,507	4,039	[1]	4,507
TDRs individually evaluated for impairment - associated allowance	570		539	570		539
Other loans individually evaluated for impairment - associated allowance	287		583	287		583
Loans collectively evaluated for impairment - associated allowance	2,114		2,399	2,114		2,399
Purchased impaired loans - associated allowance	1,068		986	1,068		986
TDRs individually evaluated for impairment	2,575		2,147	2,575		2,147
Other loans individually evaluated for impairment	1,336		2,076	1,336		2,076
Loans collectively evaluated for impairment	170,204		143,393	170,204		143,393
Purchased impaired loans	7,749		6,927	7,749		6,927	6,667
Total loans	181,864	[1],[2],[3],[4]	154,543	181,864	[1],[2],[3],[4]	154,543	159,014	[1],[2],[3],[4]
Portfolio segment ALLL as a percentage of total ALLL	100.00%		100.00%	100.00%		100.00%
Ratio of the allowance for loan and lease losses to total loans	2.22%		2.92%	2.22%		2.92%
Total commercial lending [Member]
Beginning Balance				1,995		2,567
Charge-offs				(602)		(959)
Recoveries				331		358
Net charge-offs				(271)		(601)
Provision for credit losses				93		268
Net change in allowance for unfunded loan commitments and letters of credit				1		(13)
Other				1		(1)
Ending Balance	1,819		2,220	1,819		2,220
TDRs individually evaluated for impairment - associated allowance	43		28	43		28
Other loans individually evaluated for impairment - associated allowance	287		583	287		583
Loans collectively evaluated for impairment - associated allowance	1,260		1,366	1,260		1,366
Purchased impaired loans - associated allowance	229		243	229		243
TDRs individually evaluated for impairment	556		396	556		396
Other loans individually evaluated for impairment	1,336		2,076	1,336		2,076
Loans collectively evaluated for impairment	101,906		81,420	101,906		81,420
Purchased impaired loans	1,402		957	1,402		957
Total loans	105,200		84,849	105,200		84,849
Portfolio segment ALLL as a percentage of total ALLL	45.00%		49.00%	45.00%		49.00%
Ratio of the allowance for loan and lease losses to total loans	1.73%		2.62%	1.73%		2.62%
Total consumer lending [Member]
Beginning Balance				2,352		2,320
Charge-offs				(808)		(823)
Recoveries				100		112
Net charge-offs				(708)		(711)
Provision for credit losses				576		694
Net change in allowance for unfunded loan commitments and letters of credit						(16)
Ending Balance	2,220		2,287	2,220		2,287
TDRs individually evaluated for impairment - associated allowance	527		511	527		511
Loans collectively evaluated for impairment - associated allowance	854		1,033	854		1,033
Purchased impaired loans - associated allowance	839		743	839		743
TDRs individually evaluated for impairment	2,019		1,751	2,019		1,751
Loans collectively evaluated for impairment	68,298		61,973	68,298		61,973
Purchased impaired loans	6,347		5,970	6,347		5,970
Total loans	$ 76,664		$ 69,694	$ 76,664		$ 69,694
Portfolio segment ALLL as a percentage of total ALLL	55.00%		51.00%	55.00%		51.00%
Ratio of the allowance for loan and lease losses to total loans	2.90%		3.28%	2.90%		3.28%

[1] Amounts represent the assets or liabilities of consolidated variable interest entities (VIEs).

[2] Amounts represent items for which the Corporation has elected the fair value option.

[3] Net of unearned income, net deferred loan fees, unamortized discounts and premiums, and purchase discounts and premiums totaling $2.9 billion and $2.3 billion atSeptember 30, 2012 and December 31, 2011, respectively.

[4] Future accretable yield related to purchased impaired loans is not included in loans outstanding.