Loans and Allowance for Credit Losses, PCI, by FICO Score, Consumer (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Purchased Credit Impaired Loans by FICO [Abstract]
Purchased Credit Impaired Loans (carrying value)	$ 32,513	$ 36,719
Residential Mortgage [Member]
Purchased Credit Impaired Loans by FICO [Abstract]
Purchased Credit Impaired Loans (carrying value)	27,716	29,952
Residential Mortgage [Member] | Purchased Credit-Impaired Loans [Member]
Purchased Credit Impaired Loans by FICO [Abstract]
Less than 600	13,947	17,379
600-639	7,075	7,572
640-679	6,818	6,735
680-719	3,747	3,745
720-759	1,792	1,889
760-799	893	909
Greater than 800	201	217
No FICO available	173	298
Total consumer PCI loans (adjusted unpaid principal balance)	34,646	38,744
Purchased Credit Impaired Loans (carrying value)	27,716	29,952
Real estate 1-4 family first mortgage [Member]
Purchased Credit Impaired Loans by FICO [Abstract]
Purchased Credit Impaired Loans (carrying value)	27,535	29,746
Real estate 1-4 family first mortgage [Member] | Purchased Credit-Impaired Loans [Member]
Purchased Credit Impaired Loans by FICO [Abstract]
Less than 600	13,781	17,169
600-639	6,996	7,489
640-679	6,731	6,646
680-719	3,698	3,698
720-759	1,777	1,875
760-799	886	903
Greater than 800	200	215
No FICO available	161	284
Total consumer PCI loans (adjusted unpaid principal balance)	34,230	38,279
Purchased Credit Impaired Loans (carrying value)	27,535	29,746
Real estate 1-4 family junior lien mortgage [Member]
Purchased Credit Impaired Loans by FICO [Abstract]
Purchased Credit Impaired Loans (carrying value)	181	206
Real estate 1-4 family junior lien mortgage [Member] | Purchased Credit-Impaired Loans [Member]
Purchased Credit Impaired Loans by FICO [Abstract]
Less than 600	166	210
600-639	79	83
640-679	87	89
680-719	49	47
720-759	15	14
760-799	7	6
Greater than 800	1	2
No FICO available	12	14
Total consumer PCI loans (adjusted unpaid principal balance)	416	465
Purchased Credit Impaired Loans (carrying value)	$ 181	$ 206