Fair Value Disclosures (Changes In Level 3 Assets And Liabilities Measured At Fair Value On Recurring Basis) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended					3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended		9 Months Ended		3 Months Ended						9 Months Ended				3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended			3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended				9 Months Ended				3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2011 Equity Securities (CDOs) [Member]		Sep. 30, 2011 Equity Securities (CDOs) [Member]		Sep. 30, 2012 Equity Securities (CDOs) [Member]	Jun. 30, 2012 Equity Securities (CDOs) [Member]	Dec. 31, 2011 Equity Securities (CDOs) [Member]	Sep. 30, 2012 Consolidated Sponsored Investment Funds, Hedge Funds / Funds Of Funds [Member]		Sep. 30, 2011 Consolidated Sponsored Investment Funds, Hedge Funds / Funds Of Funds [Member]		Sep. 30, 2012 Consolidated Sponsored Investment Funds, Hedge Funds / Funds Of Funds [Member]		Sep. 30, 2011 Consolidated Sponsored Investment Funds, Hedge Funds / Funds Of Funds [Member]		Sep. 30, 2012 Consolidated Sponsored Investment Funds, Private Equity Funds Of Funds [Member]		Sep. 30, 2011 Consolidated Sponsored Investment Funds, Private Equity Funds Of Funds [Member]		Sep. 30, 2012 Consolidated Sponsored Investment Funds, Private Equity Funds Of Funds [Member]		Sep. 30, 2011 Consolidated Sponsored Investment Funds, Private Equity Funds Of Funds [Member]		Sep. 30, 2012 Consolidated Sponsored Investment Funds, Other Funds Of Hedge Funds [Member]		Sep. 30, 2011 Consolidated Sponsored Investment Funds, Other Funds Of Hedge Funds [Member]		Sep. 30, 2012 Consolidated Sponsored Investment Funds, Other Funds Of Hedge Funds [Member]		Sep. 30, 2011 Consolidated Sponsored Investment Funds, Other Funds Of Hedge Funds [Member]		Sep. 30, 2012 Investments In Private Equity Funds [Member]		Sep. 30, 2011 Investments In Private Equity Funds [Member]		Sep. 30, 2012 Investments In Private Equity Funds [Member]		Sep. 30, 2011 Investments In Private Equity Funds [Member]		Sep. 30, 2012 Equity Method, Real Estate Funds [Member]		Sep. 30, 2011 Equity Method, Real Estate Funds [Member]		Sep. 30, 2012 Equity Method, Real Estate Funds [Member]		Sep. 30, 2011 Equity Method, Real Estate Funds [Member]		Sep. 30, 2012 Investments Of Consolidated Funds [Member]		Sep. 30, 2011 Investments Of Consolidated Funds [Member]		Sep. 30, 2012 Investments Of Consolidated Funds [Member]		Sep. 30, 2011 Investments Of Consolidated Funds [Member]		Sep. 30, 2012 Consolidated Equity Securities [Member]	Sep. 30, 2011 Consolidated Equity Securities [Member]	Sep. 30, 2012 Consolidated Equity Securities [Member]	Sep. 30, 2011 Consolidated Equity Securities [Member]	Sep. 30, 2012 Debt Securities [Member]	Sep. 30, 2012 Separate Account Derivatives [Member]	Sep. 30, 2012 Assets Of Consolidated VIEs Bank Loans [Member]		Sep. 30, 2011 Assets Of Consolidated VIEs Bank Loans [Member]		Sep. 30, 2012 Assets Of Consolidated VIEs Bank Loans [Member]		Sep. 30, 2011 Assets Of Consolidated VIEs Bank Loans [Member]		Sep. 30, 2012 Assets Of Consolidated VIEs Bonds [Member]	Sep. 30, 2012 Assets Of Consolidated VIEs Bonds [Member]	Sep. 30, 2012 Equity Method, Private Equity Funds [Member]	Sep. 30, 2012 Equity Method, Private Equity Funds [Member]	Sep. 30, 2011 Equity Method, Private Equity Funds [Member]	Jun. 30, 2011 Equity Method, Private Equity Funds [Member]	Sep. 30, 2012 Total Level 3 Assets Of Consolidated VIEs [Member]		Sep. 30, 2011 Total Level 3 Assets Of Consolidated VIEs [Member]		Sep. 30, 2012 Total Level 3 Assets Of Consolidated VIEs [Member]		Sep. 30, 2011 Total Level 3 Assets Of Consolidated VIEs [Member]		Sep. 30, 2012 Total Level 3 assets [Member]		Sep. 30, 2011 Total Level 3 assets [Member]		Sep. 30, 2012 Total Level 3 assets [Member]		Sep. 30, 2011 Total Level 3 assets [Member]		Sep. 30, 2012 Liabilities Of Consolidated Vies [Member]		Sep. 30, 2011 Liabilities Of Consolidated Vies [Member]		Sep. 30, 2012 Liabilities Of Consolidated Vies [Member]		Sep. 30, 2011 Liabilities Of Consolidated Vies [Member]		Sep. 30, 2011 Separate Account Assets, Debt Securities [Member]	Sep. 30, 2012 Separate Account Assets, Debt Securities [Member]	Sep. 30, 2011 Separate Account Assets, Debt Securities [Member]	Sep. 30, 2011 Total Level 3 Separate Account Assets [Member]	Sep. 30, 2012 Total Level 3 Separate Account Assets [Member]	Sep. 30, 2011 Total Level 3 Separate Account Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value, Beginning balance	$ 2		$ 2		$ 1	$ 1	$ 1	$ 46		$ 17		$ 22		$ 19		$ 298		$ 312		$ 313		$ 299		$ 187		$ 211		$ 193		$ 226		$ 88		$ 77		$ 85		$ 68		$ 101		$ 48		$ 88		$ 36		$ 721		$ 667		$ 702		$ 650		$ 7	$ 4	$ 3	$ 4		$ 7	$ 85		$ 41		$ 83		$ 32		$ 44	$ 40	$ 25	$ 27	$ 30	$ 29	$ 154		$ 70		$ 150		$ 62		$ 882		$ 751		$ 862		$ 886		$ 1,439		$ 1,292		$ 1,574		$ 1,278		$ 10	$ 7	$ 170	$ 14	$ 10	$ 174
Realized and unrealized gains (losses) in earnings and OCI	(1)							8		(2)		4		(1)		22		(7)		43		23		14		(19)		33		(7)		1		3		7		10		6		3		8		5		51		(23)		95		30		(4)	(1)	(5)	1		(4)	2		(2)		2		(4)		1	3	2	4	3		5		(2)		9		(1)		52		(27)		99		27		(27)		38		(66)		10		(1)		(3)	(2)	(5)	(2)
Purchases								3				30								2		8								5		1		1		4		4		6		5		19		17		10		6		55		34		3	1	7	8	3	6	7		5		25		25			2	2	2			9		5		29		25		25		12		94		163											3	96	1	10	104
Sales and maturities								(2)				(2)		(2)		(14)		(10)		(46)		(38)								(1)										(7)				(7)				(23)		(10)		(55)		(41)		(7)	(3)	(12)	(41)		(7)	(24)				(31)		(16)				(3)	(7)	(4)		(27)				(38)		(20)		(57)		(14)		(111)		(270)										(1)	(6)	(168)	(4)	(18)	(209)
Issuances and other settlements			(1)	[1]						(1)	[1]	(2)	[1]	(1)	[1]	(8)	[1]	(1)	[1]	(8)	[1]			(21)	[1]			(46)	[1]	(31)	[1]					(6)	[1]	(1)	[1]	(3)	[1]	(1)	[1]	(5)	[1]	(3)	[1]	(32)	[1]	(3)	[1]	(67)	[1]	(37)	[1]							7	[1]	16	[1]	7	[1]	16	[1]							7	[1]	16	[1]	7	[1]	16	[1]	(25)	[1]	13	[1]	(60)	[1]	(21)	[1]	377	[1]	332	[1]	203	[1]	318	[1]
Transfer into Level 3												3										2																														3		2		34		48	38		34	36		23		89		46								36		23		89		46		70		23		140		86														48	38
Transfers out of Level 3														(1)						(6)																																(6)		(1)				(8)	(9)			(24)		(11)		(86)		(27)								(24)		(11)		(86)		(27)		(24)		(11)		(101)		(124)											(1)	(87)		(9)	(96)
Assets measured at fair value, Ending balance	1		1		1	1	1	55		14		55		14		298		294		298		294		180		192		180		192		90		81		90		81		103		55		103		55		727		637		727		637		33	1	33	1	3	36	89		72		89		72		45	45	26	26	29	29	160		101		160		101		923		747		923		747		1,843		1,586		1,843		1,586		8	3	8	9	36	9
Total net gains (losses) included in earnings	$ (1)	[2]						$ 8	[2]	$ (1)	[2]	$ 4	[2]			$ 20	[2]	$ (10)	[2]	$ 38	[2]	$ 20	[2]	$ 14	[2]	$ (20)	[2]	$ 33	[2]	$ (7)	[2]	$ 2	[2]	$ 2	[2]	$ 8	[2]	$ 10	[2]	$ 4	[2]	$ 3	[2]	$ 6	[2]	$ 5	[2]	$ 48	[2]	$ (27)	[2]	$ 89	[2]	$ 28	[2]

[1] Amount includes distributions from equity method investees, repayments of borrowings of consolidated VIEs, and loans and borrowings related to the consolidation of one additional CLO.

[2] Earnings attributable to the change in unrealized gains (losses) relating to assets still held at the reporting date.