Loans - Status of Consumer Loan Portfolio (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012		Jun. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	$ 1,403		$ 1,629
Accruing Loans Contractually Past Due 90 days or More	40		80
Total loans	66,705		63,258		56,064
Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	18,302		17,936
Nonaccrual Loans	1,107		1,129
Accruing Loans Contractually Past Due 90 days or More	32		43
Total loans	19,441		19,108
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	14,824		14,333
Nonaccrual Loans	1,013		1,038
Accruing Loans Contractually Past Due 90 days or More	0		0
Total loans	15,837		15,371		14,758
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	2,083		2,238
Nonaccrual Loans	89		86
Accruing Loans Contractually Past Due 90 days or More	0		0
Total loans	2,172		2,324		2,455
Consumer Loans [Member] | Total residential mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	16,907		16,571
Nonaccrual Loans	1,102	[1]	1,124	[1]
Accruing Loans Contractually Past Due 90 days or More	0		0
Total loans	18,009		17,695
Consumer Loans [Member] | Credit Card Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	847		800
Nonaccrual Loans	0		0
Accruing Loans Contractually Past Due 90 days or More	11		15
Total loans	858		815		783
Consumer Loans [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	548		565
Nonaccrual Loans	5		5
Accruing Loans Contractually Past Due 90 days or More	21		28
Total loans	$ 574		$ 598		$ 651

[1] Nonaccrual residential mortgages includes all receivables which are 90 or more days contractually delinquent as well as loans discharged under Chapter 7 bankruptcy and not re-affirmed and second lien loans where the first lien loan that we own or service is 90 or more days contractually delinquent.