Loans and Allowance for Credit Losses, PCI, by FICO Score, Consumer (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
By FICO:
Purchased Credit Impaired Loans (carrying value)	$ 21,555	$ 23,320
Residential Mortgage [Member]
By FICO:
Purchased Credit Impaired Loans (carrying value)	20,682	21,813
Residential Mortgage [Member] | Purchased Credit-Impaired Loans [Member]
By FICO:
Less than 600	7,042	7,783
600-639	5,086	5,469
640-679	6,518	6,787
680-719	4,210	4,047
720-759	1,781	1,741
760-799	886	881
800 and greater	224	221
No FICO available	96	107
Total consumer PCI loans (adjusted unpaid principal balance)	25,843	27,036
Purchased Credit Impaired Loans (carrying value)	20,682	21,813
Real estate 1-4 family first mortgage [Member]
By FICO:
Purchased Credit Impaired Loans (carrying value)	20,601	21,712
Real estate 1-4 family first mortgage [Member] | Purchased Credit-Impaired Loans [Member]
By FICO:
Less than 600	6,970	7,708
600-639	5,048	5,416
640-679	6,467	6,718
680-719	4,167	4,008
720-759	1,758	1,728
760-799	875	875
800 and greater	222	220
No FICO available	89	97
Total consumer PCI loans (adjusted unpaid principal balance)	25,596	26,770
Purchased Credit Impaired Loans (carrying value)	20,601	21,712
Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Purchased Credit Impaired Loans (carrying value)	81	101
Real estate 1-4 family junior lien mortgage [Member] | Purchased Credit-Impaired Loans [Member]
By FICO:
Less than 600	72	75
600-639	38	53
640-679	51	69
680-719	43	39
720-759	23	13
760-799	11	6
800 and greater	2	1
No FICO available	7	10
Total consumer PCI loans (adjusted unpaid principal balance)	247	266
Purchased Credit Impaired Loans (carrying value)	$ 81	$ 101