Premises and Equipment (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Land		$ 310	$ 321
Buildings and Improvements, Gross		1,059	1,047
Leasehold improvements		758	691
Furniture and equipment		1,429	1,430
Capitalized Computer Software, Gross	[1]	1,890	1,671
Construction in progress		351	488
Property, Plant and Equipment, Gross, Total		5,797	5,648
Less accumulated depreciation and amortization		3,773	3,595
Premises and equipment	[2]	$ 2,024	$ 2,053
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		50 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
Software and Software Development Costs [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		1 year	1 year
Software and Software Development Costs [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life		5 years	5 years

[1] Beginning October 1, 2018, the Company reclassified capitalized software and related accumulated amortization previously presented in Other assets to Premises, property, and equipment, net, on the Consolidated Balance Sheets. Prior periods have been revised to conform to the current presentation for comparability.

[2] Beginning October 1, 2018, the Company reclassified software and related accumulated amortization previously presented in Other assets to Premises, property, and equipment, net. Reclassifications have been made to previously reported amounts for comparability.