Loans - Status of Consumer Loan Portfolio (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Nonaccrual Loans	$ 1,466		$ 1,629
Accruing Loans Contractually Past Due 90 days or More	40		80
Total loans	62,932		63,258		53,869
Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	18,153		17,936
Nonaccrual Loans	1,105		1,129
Accruing Loans Contractually Past Due 90 days or More	35		43
Total loans	19,293		19,108
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	14,704		14,333
Nonaccrual Loans	1,026		1,038
Accruing Loans Contractually Past Due 90 days or More	0		0
Total loans	15,730		15,371		14,344
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	2,162		2,238
Nonaccrual Loans	74		86
Accruing Loans Contractually Past Due 90 days or More	0		0
Total loans	2,236		2,324		2,491
Consumer Loans [Member] | Total residential mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	16,866		16,571
Nonaccrual Loans	1,100	[1]	1,124	[1]
Accruing Loans Contractually Past Due 90 days or More	0		0
Total loans	17,966		17,695
Consumer Loans [Member] | Credit Card Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	736		800
Nonaccrual Loans	0		0
Accruing Loans Contractually Past Due 90 days or More	13		15
Total loans	749		815		786
Consumer Loans [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans	551		565
Nonaccrual Loans	5		5
Accruing Loans Contractually Past Due 90 days or More	22		28
Total loans	$ 578		$ 598		$ 679

[1] Nonaccrual residential mortgages includes all receivables which are 90 or more days contractually delinquent as well as second lien loans where the first lien loan that we own or service is 90 or more days contractually delinquent.