MSR (Activity Related to Mortgage Banking Net Revenue) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale
Residential mortgage loan sales	[1]	$ 6,927	$ 5,078	[2]	$ 5,467
Origination fees and gains on loan sales		186	171		153
Gross mortgage servicing fees		$ 199	$ 222		$ 246

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

[2] Excludes $ 568 of HFS residential mort gage loans previously modified in a TDR that were sold d uring the first quarter of 2015 .