Activity Related to Mortgage Banking Net Revenue (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale
Residential mortgage loan sales	[1]	$ 1,377	$ 1,523	$ 2,378	[2]	$ 3,195
Origination fees and gains on loan sales		43	42	87		84
Servicing fees		$ 56	$ 62	$ 115		$ 125

[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.