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	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 Investment And Embedded Derivative Instruments [Member]	Dec. 31, 2012 Investment And Embedded Derivative Instruments [Member]	Sep. 30, 2013 Other Derivative Instruments [Member]	Dec. 31, 2012 Other Derivative Instruments [Member]	Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Foreign Exchange Future [Member]	Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Foreign Exchange Future [Member]	Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Cross Currency Swap [Member]	Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Cross Currency Swap [Member]	Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Futures Contracts On Money Market Instruments [Member]	Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Futures Contracts On Money Market Instruments [Member]	Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Futures contracts on notes and bonds [Member]	Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Futures contracts on notes and bonds [Member]	Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Single-Stock Future [Member]		Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Single-Stock Future [Member]		Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Options On Equity Market Indices [Member]		Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Options On Equity Market Indices [Member]		Sep. 30, 2013 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Other Derivatives [Member]	Dec. 31, 2012 Accounts Payable, Accrued Expenses, And Other Liabilities [Member] Other Derivatives [Member]	Sep. 30, 2013 Fixed Maturities Available For Sale [Member] Convertibles and Bonds with Warrants Attached [Member]	Dec. 31, 2012 Fixed Maturities Available For Sale [Member] Convertibles and Bonds with Warrants Attached [Member]	Sep. 30, 2013 Accounts Payable Future Policy Benefits [Member] Guaranteed Living Benefits [Member]		Dec. 31, 2012 Accounts Payable Future Policy Benefits [Member] Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Document Fiscal Year Focus	2013
Fair Value		$ 298	$ 320	$ 15	$ 24	$ (7)	$ 0			$ 2	$ 1	$ (13)	$ 10	$ 7	[1]	$ (6)	[1]	$ 10	[1]	$ 30	[1]	$ (2)		$ 291	$ 309	$ (746)	[2]	$ (1,352)	[2]
Notional Value/Payment Provision		$ 6,453	$ 4,574	$ 1,848	$ 2,558	$ 1,205	$ 620	$ 50	$ 50	$ 3,910	$ 2,710	$ 1,022	$ 915	$ 1,585	[1]	$ 2,308	[1]	$ 250	[1]	$ 250	[1]	$ 13	$ 0	$ 242	$ 279	$ 461	[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.