Loans and Allowance for Credit Losses, 90 Days or More Past Due and Still Accruing (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	$ 15,161	$ 17,810
FHA Insured/VA Guaranteed [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	14,359	16,827
Student Loans guaranteed under FFELP [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	46	63
Total Consumer [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	729	873
Total, not government insured/guaranteed [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	756	920
Total, not government insured/guaranteed [Member] | Total Commercial [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	27	47
Total, not government insured/guaranteed [Member] | Commercial and Industrial Loans [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	17	31
Total, not government insured/guaranteed [Member] | Commercial Real Estate Mortgage [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	10	16
Total, not government insured/guaranteed [Member] | Commercial Real Estate Construction [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	0	0
Total, not government insured/guaranteed [Member] | Total Consumer [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	729	873
Total, not government insured/guaranteed [Member] | Real estate 1-4 family first mortgage [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	220	260
Total, not government insured/guaranteed [Member] | Real estate 1-4 family junior lien mortgage [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	65	83
Total, not government insured/guaranteed [Member] | Credit Card [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	304	364
Total, not government insured/guaranteed [Member] | Automobile [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	51	73
Total, not government insured/guaranteed [Member] | Other revolving credit and installment [Member]
Loans 90 days or more past due and still accruing:
90 days or more past due and still accruing	$ 89	$ 93