Loans and Allowance for Credit Losses, PCI, by Loan to Value Ratio, Consumer (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
By LTV/CLTV:
Purchased Credit Impaired Loans (carrying value)	$ 21,555	$ 23,320
Residential Mortgage [Member]
By LTV/CLTV:
Purchased Credit Impaired Loans (carrying value)	20,682	21,813
Real estate 1-4 family first mortgage [Member]
By LTV/CLTV:
Purchased Credit Impaired Loans (carrying value)	20,601	21,712
Real estate 1-4 family junior lien mortgage [Member]
By LTV/CLTV:
Purchased Credit Impaired Loans (carrying value)	81	101
Purchased Credit-Impaired Loans [Member] | Residential Mortgage [Member]
By LTV/CLTV:
0-60%	4,586	4,343
60.01-80%	10,509	11,335
80.01-100%	7,457	7,843
100.01-120%	2,395	2,481
Greater than 120%	888	1,024
No LTV/CLTV available	8	10
Total consumer PCI loans (adjusted unpaid principal balance)	25,843	27,036
Purchased Credit Impaired Loans (carrying value)	20,682	21,813
Purchased Credit-Impaired Loans [Member] | Real estate 1-4 family first mortgage [Member]
By LTV/CLTV:
0-60%	4,558	4,309
60.01-80%	10,443	11,264
80.01-100%	7,374	7,751
100.01-120%	2,349	2,437
Greater than 120%	866	1,000
No LTV/CLTV available	6	9
Total consumer PCI loans (adjusted unpaid principal balance)	25,596	26,770
Purchased Credit Impaired Loans (carrying value)	20,601	21,712
Purchased Credit-Impaired Loans [Member] | Real estate 1-4 family junior lien mortgage [Member]
By LTV/CLTV:
0-60%	28	34
60.01-80%	66	71
80.01-100%	83	92
100.01-120%	46	44
Greater than 120%	22	24
No LTV/CLTV available	2	1
Total consumer PCI loans (adjusted unpaid principal balance)	247	266
Purchased Credit Impaired Loans (carrying value)	$ 81	$ 101