Loans - Status of Consumer Loan Portfolio (Detail) - USD ($) $ in Millions		Jun. 30, 2016		Dec. 31, 2015	Jun. 30, 2015
Financing Receivable, Recorded Investment [Line Items]
Accruing Loans Contractually Past Due 90 days or More		$ 17		$ 17
Total loans		79,810		82,917	$ 83,617
Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans		19,741		19,563
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest		510		885
Accruing Loans Contractually Past Due 90 days or More		16		16
Total loans		20,267		20,464
Consumer Loans [Member] | Residential Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans		17,230	[1]	16,944
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	[2],[3],[4],[5]	437		814
Accruing Loans Contractually Past Due 90 days or More		0	[1]	0
Total loans		17,667	[1],[6]	17,758	17,233
Consumer Loans [Member] | Home Equity Mortgages [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans		1,438		1,529
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	[2],[4]	73		71
Accruing Loans Contractually Past Due 90 days or More		0		0
Total loans		1,511		1,600	1,686
Consumer Loans [Member] | Credit Cards [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans		659		690
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest		0		0
Accruing Loans Contractually Past Due 90 days or More		9		9
Total loans		668		699	692
Consumer Loans [Member] | Other consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Performing Loans		414		400
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest		0		0
Accruing Loans Contractually Past Due 90 days or More		7		7
Total loans		$ 421		$ 407	$ 410

[1] The decrease in nonaccrual loans at June 30, 2016 reflects the impact of the transfer of certain residential mortgage loans with a carrying value of $369 million to held for sale during the first half of 2016.

[2] At June 30, 2016 and December 31, 2015, nonaccrual consumer mortgage loans held for investment include $428 million and $768 million, respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell.

[3] Nonaccrual consumer mortgage loans for all periods does not include guaranteed loans purchased from the Government National Mortgage Association. Repayment of these loans are predominantly insured by the Federal Housing Administration and as such, these loans have different risk characteristics from the rest of our consumer loan portfolio.

[4] Nonaccrual consumer mortgage loans held for investment include all loans 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.

[5] The trend in nonaccrual loans reflects the impact of the transfer of certain residential mortgage loans with a carrying value of $369 million to held for sale during the first half of 2016.

[6] The decrease in past due loans at June 30, 2016 reflects the impact of the transfer of certain residential mortgage loans with a carrying value of $369 million to held for sale during the first half of 2016. See Note 6, "Loans Held for Sale," for additional details.