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, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value	$ 223		$ 320
Notional Value/Payment Provision	7,398		4,574
Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(20)		24
Notional Value/Payment Provision	2,505		2,558
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign Exchange Future [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(48)		0
Notional Value/Payment Provision	534		620
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Cross Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	50		50
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value	1		1
Notional Value/Payment Provision	2,169		2,710
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures contracts on notes and bonds [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(4)		10
Notional Value/Payment Provision	1,079		915
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	3,335		0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(37)	[1]	(6)	[1]
Notional Value/Payment Provision	2,255	[1]	2,308	[1]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Fair Value	17	[1]	30	[1]
Notional Value/Payment Provision	250	[1]	250	[1]
Fixed Maturities Available For Sale [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Fair Value	274		309
Notional Value/Payment Provision	231		279
Accounts Payable Future Policy Benefits [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(985)	[2]	(1,352)	[2]
Notional Value/Payment Provision	$ 721	[2]	$ 1,100	[2]

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

[2] 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.