Commitments, Contingencies, And Guarantees (Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)		$ (344)	$ (63)	$ (272)	$ (233)
Foreign Exchange Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)		15	19	30	15
All Other Futures Contracts And Options [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)		(23)	(15)	(10)	(55)
Convertibles and Bonds with Warrants Attached [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	[1]	(14)	(17)	(14)	(13)
Investment And Embedded Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)		(22)	(13)	6	(53)
Guaranteed Living Benefits [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	[2]	(396)	(80)	(337)	(126)
Single-Stock Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	[3]	84	(15)	71	(103)
Options On Equity Market Indices [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	[3]	(1)	0	(2)	(3)
Guaranteed Living Benefit And Other Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)		(322)	(50)	(278)	(180)
Other Derivatives [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)		$ (9)	$ 45	$ (10)	$ 52

[1] (1) Includes embedded derivatives.

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

[3] (3) Related to GMDB and GLB blocks of business.