Activity Related to Mortgage Banking Net Revenue (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale
Residential mortgage loan sales	[1]	$ 1,421	$ 1,228	$ 3,798	[2]	$ 4,423
Origination fees and gains on loan sales		46	34	134		117
Servicing fees		$ 54	$ 61	$ 169		$ 186

[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.