MSR (Activity Related to Mortgage Banking Net Revenue) (Parenthetical) (Detail) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015	[2]
Mortgage Loans On Real Estate [Line Items]
Residential mortgage loan sales	[1]	$ 1,631	$ 1,377		$ 2,745	$ 2,378
Residential mortgage loans | Troubled Debt Restructuring
Mortgage Loans On Real Estate [Line Items]
Residential mortgage loan sales				$ 568

[1] Represents the unpaid principal balance at the time of the sale.

[2] Excludes $ 568 of HFS residential mortgage loans previously modified in a TDR that were sold during the first quarter of 2015 .