Nonperforming Assets (Additional Information) (Detail) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Other Real Estate	[1]	$ 62	$ 60
Accrual Loans [Member]
Financing Receivable, Modifications, Recorded Investment		2,500	2,500
Mortgage Loans in Process of Foreclosure, Amount	[2]	127	122
Proceeds due from FHA or VA [Member]
Mortgage Loans in Process of Foreclosure, Amount	[2]	119	114
Other Real Estate		50	50
Nonaccrual loans [Member]
Mortgage Loans in Process of Foreclosure, Amount	[2]	94	85
Residential Portfolio Segment [Member]
Other Real Estate	[1]	52	50
Commercial Portfolio Segment [Member]
Other Real Estate	[1]	$ 8	$ 7

[1] Does not include foreclosed real estate related to loans insured by the FHA or guaranteed by the VA. Proceeds due from the FHA and the VA are recorded as a receivable in other assets in the Consolidated Balance Sheets until the property is conveyed and the funds are received. The receivable related to proceeds due from the FHA or the VA totaled $50 million at both March 31, 2017 and December 31, 2016.

[2] Nonaccruing restructured loans are included in total nonaccrual/NPLs.