Premises and Equipment (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Land	349	358
Buildings and Improvements, Gross	1,041	1,033
Leasehold improvements	622	580
Furniture and equipment	1,357	1,322
Construction in progress	111	105
Property, Plant and Equipment, Gross, Total	3,480	3,398
Less accumulated depreciation and amortization	1,916	1,834
Premises and equipment	1,564	1,564
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	indefinite	indefinite
Minimum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	2	2
Minimum | Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	1	1
Minimum | Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	1	1
Maximum | Building and Building Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	40	40
Maximum | Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	30	30
Maximum | Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	20	20