Commitments, Contingencies, And Guarantees (Balance Sheet Locations, Fair Values In Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments) (Detail) - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		$ 1,309	$ 1,329
Cross Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		95	95
Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		4,355	2,467
Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		920	1,636
Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	[1]	277	267
Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset		308	309
Notional Value/Payment Provision		6,956	5,794
Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	[2]	1,286	1,384
Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	[2]	250	250
Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		401	10
Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		1,937	1,644
Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	[3]	786	675
Other Assets [Member] | Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset		6	12
Other Assets [Member] | Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset		1	0
Other Assets [Member] | Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset		9	6
Other Assets [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	[2]	16	0
Other Assets [Member] | Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	[2]	0	2
Other Assets [Member] | Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset		7	0
Other Assets [Member] | Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset		23	2
Other Assets [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	[3]		0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability		(13)	(7)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability		(1)	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability		(1)	(29)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	[1]	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability		(15)	(36)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	[2]	0	(21)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	[2]	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability		(3)	(4)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability		(3)	(25)
Fixed Maturities Available For Sale [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Asset	[1]	292	291
Accounts Payable Future Policy Benefits [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Derivative Fair Value, Liability	[3]	$ (615)	$ (663)

[1] (1) Includes fair value of embedded derivatives.

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

[3] (3) Includes both future policy benefits reserves and fair value derivative adjustment. Refer to Note 5 for additional information. Note that the payment provision related to GLB is the net amount at risk. The concept of a notional value does not apply to the GLB reinsurance contracts.