Commitments, contingencies, and guarantees (Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	$ 375		$ (136)		$ (930)
Foreign Exchange Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	11		(9)		6
All Other Futures Contracts And Options [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	61		(22)		(98)
Convertibles and Bonds with Warrants Attached [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	6		25		(50)
Dollar Rolls [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	0		0		(1)
Investment And Embedded Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	78		(6)		(143)
Guaranteed Living Benefits [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	878	[1]	171	[1]	(779)	[1]
Single-Stock Future [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	(555)	[2]	(273)	[2]	(12)	[2]
Options On Equity Market Indices [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	(24)	[2]	(24)	[2]	8	[2]
Credit Default Swap [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	(2)		(4)		(4)
Guaranteed Living Benefit And Other Derivative Instruments [Member]
Commitments Contingencies And Guarantees [Line Items]
Net realized gains (losses)	$ 297		$ (130)		$ (787)

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

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