Premises and Equipment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Land	$ 320	$ 330
Buildings and Improvements, Gross	1,028	1,073
Leasehold improvements	645	636
Furniture and equipment	1,492	1,463
Construction in progress	357	249
Property, Plant and Equipment, Gross, Total	3,842	3,751
Less accumulated depreciation and amortization	2,286	2,249
Premises and equipment	$ 1,556	$ 1,502
Building and Building Improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year	1 year
Building and Building Improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	40 years	40 years
Leasehold Improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year	1 year
Leasehold Improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years	30 years
Furniture and Fixtures | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	1 year	1 year
Furniture and Fixtures | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	20 years	20 years