Details of our Loan Distribution and Industry Concentrations of Credit Risk (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 43,028		$ 43,979
Financial Institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	10,973		11,144
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,179		1,280
Wealth Management Loans and Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	7,312		7,342
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,441		1,449
Overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	3,715		4,849
Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	33,747		33,971
Domestic | Financial Institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,895		4,606
Domestic | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	763		752
Domestic | Wealth Management Loans and Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	7,312		7,342
Domestic | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,441		1,449
Domestic | Lease Financings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,518	[1]	1,558	[1]
Domestic | Other Residential Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,854		1,923
Domestic | Overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,971		2,958		3,381
Domestic | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	849		623		452
Domestic | Margin Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	13,144		12,760		9,369
Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	9,281		10,008
Foreign | Financial Institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	6,078		6,538
Foreign | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	416		528
Foreign | Lease Financings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,043	[1]	1,051	[1]
Foreign | Other loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,744		$ 1,891

[1] Net of unearned income on domestic and foreign lease financings of $1,301 million at March 31, 2012 and $1,343 million at Dec. 31, 2011.