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			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012	Dec. 31, 2012
Beginning Balance				$ 4,036	[1]	$ 4,347
Charge-offs				(925)		(929)
Recoveries				261		281
Net charge-offs				(664)		(648)
Provision for credit losses	157		256	393		441
Net change in allowance for unfunded loan commitments and letters of credit				8		16
Other				(1)
Ending Balance	3,772	[1]	4,156	3,772	[1]	4,156
TDRs individually evaluated for impairment - associated allowance	507		572	507		572
Other loans individually evaluated for impairment - associated allowance	203		419	203		419
Loans collectively evaluated for impairment - associated allowance	1,945		2,130	1,945		2,130
Purchased impaired loans - associated allowance	1,117		1,035	1,117		1,035
TDRs individually evaluated for impairment	2,842		2,319	2,842		2,319
Other loans individually evaluated for impairment	840		1,523	840		1,523
Loans collectively evaluated for impairment	179,315		168,500	179,315		168,500
Purchased impaired loans	6,778		8,083	6,778		8,083	7,406
Total loans	189,775	[1],[2]	180,425	189,775	[1],[2]	180,425	185,856	[1],[2]
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	1.99%		2.30%	1.99%		2.30%
Loans collectively evaluated for impairment - based upon collateral values	291			291
Total commercial lending [Member]
Beginning Balance				1,774		1,995
Charge-offs				(336)		(403)
Recoveries				185		214
Net charge-offs				(151)		(189)
Provision for credit losses				28		88
Net change in allowance for unfunded loan commitments and letters of credit				8		7
Other				(1)
Ending Balance	1,658		1,901	1,658		1,901
TDRs individually evaluated for impairment - associated allowance	25		45	25		45
Other loans individually evaluated for impairment - associated allowance	203		419	203		419
Loans collectively evaluated for impairment - associated allowance	1,247		1,210	1,247		1,210
Purchased impaired loans - associated allowance	183		227	183		227
TDRs individually evaluated for impairment	599		483	599		483
Other loans individually evaluated for impairment	840		1,523	840		1,523
Loans collectively evaluated for impairment	110,863		100,607	110,863		100,607
Purchased impaired loans	968		1,532	968		1,532
Total loans	113,270		104,145	113,270		104,145
Portfolio segment ALLL as a percentage of total ALLL	44.00%		46.00%	44.00%		46.00%
Ratio of the allowance for loan and lease losses to total loans	1.46%		1.83%	1.46%		1.83%
Total consumer lending [Member]
Beginning Balance				2,262		2,352
Charge-offs				(589)		(526)
Recoveries				76		67
Net charge-offs				(513)		(459)
Provision for credit losses				365		353
Net change in allowance for unfunded loan commitments and letters of credit						9
Ending Balance	2,114		2,255	2,114		2,255
TDRs individually evaluated for impairment - associated allowance	482		527	482		527
Loans collectively evaluated for impairment - associated allowance	698		920	698		920
Purchased impaired loans - associated allowance	934		808	934		808
TDRs individually evaluated for impairment	2,243		1,836	2,243		1,836
Loans collectively evaluated for impairment	68,452		67,893	68,452		67,893
Purchased impaired loans	5,810		6,551	5,810		6,551
Total loans	$ 76,505		$ 76,280	$ 76,505		$ 76,280
Portfolio segment ALLL as a percentage of total ALLL	56.00%		54.00%	56.00%		54.00%
Ratio of the allowance for loan and lease losses to total loans	2.76%		2.96%	2.76%		2.96%

[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.