Fair Value Disclosures (Fair Value Of Financial Assets And Financial Liabilities) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011		Sep. 30, 2011	Dec. 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 4,223		$ 3,506		$ 2,983	$ 3,367
Due from related parties	121		142
Due to related parties	15		22
Short-term borrowings	100		100
Long-term borrowings	6,186		4,690
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	4,223	[1]	3,506	[1]
Accounts receivable	2,464	[2]	1,960	[2]
Due from related parties	121	[2]	142	[2]
Cash and cash equivalents of consolidated VIEs	292	[1]	54	[1]
Accounts payable and accrued liabilities	1,427	[2]	923	[2]
Due to related parties	15	[2]	22	[2]
Short-term borrowings	100	[2]	100	[2]
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings	6,186	[3]	4,690	[3]
Estimate of Fair Value, Fair Value Disclosure [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	4,223		3,506
Accounts receivable	2,464		1,960
Due from related parties	121		142
Cash and cash equivalents of consolidated VIEs	292		54
Accounts payable and accrued liabilities	1,427		923
Due to related parties	15		22
Short-term borrowings	100		100
Estimate of Fair Value, Fair Value Disclosure [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term borrowings	$ 6,767		$ 5,057

[1] Cash and cash equivalents are carried at either cost or amortized cost that approximates fair value due to their short-term maturities. At September 30, 2012 and December 31, 2011, approximately $46 million and $196 million, respectively, related to cash and cash equivalents held by consolidated sponsored investment funds. Money market funds are valued through the use of quoted market prices, or $1.00, which generally is the NAV of the fund. At September 30, 2012 and December 31, 2011, approximately $17 million and $123 million, respectively, of money market funds were recorded within cash and cash equivalents on the Company's condensed consolidated statements of financial condition.

[2] The carrying amounts of accounts receivable, due from related parties, accounts payable and accrued liabilities, due to related parties and short-term borrowings approximate fair value due to their short-term nature.

[3] Long-term borrowings are recorded at amortized cost. The fair value of the Company's long-term borrowings, including the current portion of long-term borrowings, is estimated using market prices at the end of September 2012 and December 2011, respectively. See Note 10, Borrowings, for the fair value of each of the Company's long-term borrowings.