Investments (Summary Of The Cost And Carrying Value Of Other Investments) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule of Investments [Line Items]
Cost	$ 1,241	$ 1,186
Carrying Value	1,445	1,207
Consolidated Sponsored Investment Funds [Member]
Schedule of Investments [Line Items]
Cost	396	345
Carrying Value	436	373
Equity Method [Member]
Schedule of Investments [Line Items]
Cost	465	487
Carrying Value	509	457
Deferred Compensation Plan Mutual Fund Investments [Member]
Schedule of Investments [Line Items]
Cost	15	17
Carrying Value	10	19
Federal Reserve Bank Advances [Member]
Schedule of Investments [Line Items]
Cost	330	328
Carrying Value	330	328
Other [Member]
Schedule of Investments [Line Items]
Cost	35	9
Carrying Value	35	9
Total Cost Method Investments [Member]
Schedule of Investments [Line Items]
Cost	365	337
Carrying Value	365	337
Carried Interest [Member]
Schedule of Investments [Line Items]
Carrying Value	$ 125	$ 21