Loans - Additional Information (Detail) (USD $)	3 Months Ended			27 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Mar. 31, 2014		Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 68,897,000,000		$ 62,932,000,000	$ 68,897,000,000		$ 67,695,000,000
Net deferred origination fees	9,000,000			9,000,000		23,000,000
Net unamortized premium on loans	15,000,000			15,000,000		16,000,000
Amortized net premiums on loans, less than for March 31, 2014	1,000,000		2,000,000
Total nonaccruing loans	1,175,000,000			1,175,000,000		1,305,000,000
Interest income that would have been recorded if the nonaccrual receivable had been current in accordance with contractual terms during the period	28,000,000		31,000,000
Current interest income (expense) in finance loans	12,000,000		5,000,000
Residential mortgage loan delinquency carried at lower of amortized cost or fair value less cost to sell	1,041,000,000			1,041,000,000		1,074,000,000
Commercial loans removed from TDR classification				0
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	19,004,000,000			19,004,000,000		19,201,000,000
Total nonaccruing loans	978,000,000			978,000,000		1,026,000,000
Weighted average rate of reduction	1.50%		1.99%
Residential Mortgage And Home Equity [Member] | Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	17,838,000,000			17,838,000,000		17,837,000,000
Total nonaccruing loans	978,000,000	[1],[2],[3]		978,000,000	[1],[2],[3]	1,026,000,000	[1],[2],[3]
Residential mortgage loan delinquency carried at lower of amortized cost or fair value less cost to sell	853,000,000			853,000,000		866,000,000
Parent And Other Subsidiaries Of Common Parent [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 5,277,000,000			$ 5,277,000,000		$ 5,328,000,000

[1] At March 31, 2014 and December 31, 2013, residential mortgage loan nonaccrual balances include $853 million and $866 million, respectively, of loans that are carried at the lower of amortized cost or fair value of the collateral less cost to sell.

[2] Residential mortgage nonaccrual loans for all periods does not include guaranteed loans purchased from the Government National Mortgage Association ("GNMA"). 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 customer loan portfolio.

[3] 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.