Loan Sale and Servicing Activities and Variable Interest Entities (Consolidated VIEs - Carrying Value) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012	Dec. 31, 2011
Cash and due from banks	$ 4,051	[1]	$ 5,220	[1]	$ 4,136	$ 4,105
Interest-earning deposits with banks	3,797	[1]	3,984	[1]
Investment securities	57,449	[1]	61,406	[1]
Loans	189,775	[1],[2]	185,856	[1],[2]	180,425
Allowance for loan and lease losses	(3,772)	[1]	(4,036)	[1]	(4,156)	(4,347)
Equity investments	10,054	[1]	10,877	[1]
Other assets	24,297	[1],[2]	23,679	[1],[2]
Total assets	304,415		305,107
Commercial paper	6,400	[1]	8,453	[1]
Other borrowed funds	2,390	[1],[2]	1,962	[1],[2]
Accrued expenses	4,057	[1]	4,449	[1]
Other liabilities	6,032	[1]	4,594	[1]
Total liabilities	262,474		263,342
Variable Interest Entity, Primary Beneficiary [Member]
Cash and due from banks	4		4
Interest-earning deposits with banks	6		6
Investment securities	7		9
Loans	7,845		7,781
Allowance for loan and lease losses	(64)		(75)
Equity investments	492		1,429
Other assets	567		1,281
Total assets	8,857		10,435
Commercial paper	5,900		6,045
Other borrowed funds	434		257
Accrued expenses	120		132
Other liabilities	378		976
Total liabilities	6,832		7,410
Variable Interest Entity, Primary Beneficiary [Member] | Market Street [Member]
Investment securities	7		9
Loans	6,116		6,038
Other assets	6		536
Total assets	6,129		6,583
Commercial paper	5,900		6,045
Other liabilities	223		529
Total liabilities	6,123		6,574
Variable Interest Entity, Primary Beneficiary [Member] | Credit Card and Other Securitization Trusts [Member]
Loans	1,729		1,743
Allowance for loan and lease losses	(64)		(75)
Other assets	27		31
Total assets	1,692		1,699
Other borrowed funds	195
Total liabilities	195
Variable Interest Entity, Primary Beneficiary [Member] | Tax Credit Investments and Other [Member]
Cash and due from banks	4		4
Interest-earning deposits with banks	6		6
Equity investments	492		1,429
Other assets	534		714
Total assets	1,036		2,153
Other borrowed funds	239		257
Accrued expenses	120		132
Other liabilities	155		447
Total liabilities	$ 514		$ 836

[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.