Commitments, Contingencies, And Guarantees (Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	$ (60)		$ (793)		$ (271)		$ (931)
Foreign Exchange Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	(9)		15		(8)		(3)
All Other Futures Contracts And Options [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	0		(64)		(20)		(91)
Convertibles and Bonds with Warrants Attached [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	12		(41)		24		(63)
Dollar Rolls [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	1		1		1		0
Investment And Embedded Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	4		(89)		(3)		(157)
Guaranteed Living Benefits [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	83	[1]	(926)	[1]	44	[1]	(925)	[1]
Single-Stock Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	(138)	[2]	197		(286)	[2]	134	[2]
Options On Equity Market Indices [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	(9)	[2]	23	[2]	(22)	[2]	18	[2]
Credit Default Swap [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	0		2		(4)		(1)
Guaranteed Living Benefit And Other Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	$ (64)		$ (704)		$ (268)		$ (774)

[1] Excludes foreign exchange gains (losses) related to GLB.

[2] Related to GMDB and GLB blocks of business.