Nonperforming Assets (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Nonperforming loans	$ 285		$ 318		$ 329
Other assets owned	9		13		12
Total nonperforming assets	294	[1]	331	[1]	341	[1]
Domestic | Other Residential Mortgages
Financing Receivable, Impaired [Line Items]
Nonperforming loans	177		188		203
Domestic | Wealth Management Loans and Mortgages
Financing Receivable, Impaired [Line Items]
Nonperforming loans	35		35		32
Domestic | Commercial
Financing Receivable, Impaired [Line Items]
Nonperforming loans	31		32		21
Domestic | Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Nonperforming loans	30		39		40
Domestic | Financial Institutions
Financing Receivable, Impaired [Line Items]
Nonperforming loans	3		14		23
Foreign
Financing Receivable, Impaired [Line Items]
Nonperforming loans	$ 9		$ 10		$ 10

[1] Loans of consolidated investment management funds are not part of BNY Mellon's loan portfolio. Included in these loans are nonperforming loans of $155 million at June 30, 2012, $180 million at March 31, 2012 and $101 million at Dec. 31, 2011. These loans are recorded at fair value and therefore do not impact the provision for credit losses and allowance for loan losses, and accordingly are excluded from the nonperforming assets table above.