Loans and asset quality- Nonperforming Assets (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Nonperforming loans	$ 231		$ 245
Other assets owned	3		4
Total nonperforming assets	234	[1]	249	[1]
Domestic | Other residential mortgages
Financing Receivable, Impaired [Line Items]
Nonperforming loans	148		158
Domestic | Wealth management loans and mortgages
Financing Receivable, Impaired [Line Items]
Nonperforming loans	30		30
Domestic | Commercial
Financing Receivable, Impaired [Line Items]
Nonperforming loans	24		27
Domestic | Commercial real estate
Financing Receivable, Impaired [Line Items]
Nonperforming loans	17		18
Domestic | Financial institutions
Financing Receivable, Impaired [Line Items]
Nonperforming loans	3		3
Foreign
Financing Receivable, Impaired [Line Items]
Nonperforming loans	$ 9		$ 9

[1] Loans of consolidated investment management funds are not part of BNY Mellon’s loan portfolio. Included in these loans are nonperforming loans of $161 million at March 31, 2013 and $174 million at Dec. 31, 2012. 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.