Commitments, Contingencies, And Guarantees (Balance Sheet Locations, Fair Values In An Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value	$ 427		$ 528
Notional Value/Payment Provision	12,906		6,183
Other Derivatives Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value	41		25
Notional Value/Payment Provision	1,973		1,686
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign Currency Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Fair Value	7		3
Notional Value/Payment Provision	674		729
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures Contracts On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value	7		3
Notional Value/Payment Provision	10,476		4,297
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Futures Contracts On Notes And Bonds [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(4)		5
Notional Value/Payment Provision	1,055		676
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Money Market Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	292		1
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Future Contracts On Equities [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(16)	[1]	(25)	[1]
Notional Value/Payment Provision	1,367	[1]	1,069	[1]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options On Equity Market Indices [Member]
Derivatives, Fair Value [Line Items]
Fair Value	54	[1]	46	[1]
Notional Value/Payment Provision	250	[1]	250	[1]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Credit Default Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair Value	3		4
Notional Value/Payment Provision	350		350
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	6		17
Fixed Maturities Available For Sale [Member] | Convertible Bonds [Member]
Derivatives, Fair Value [Line Items]
Fair Value	357		416
Notional Value/Payment Provision	353		382
Fixed Maturities Available For Sale [Member] | To Be Announced Mortgage-Backed Securities [Member]
Derivatives, Fair Value [Line Items]
Fair Value	60		101
Notional Value/Payment Provision	56		98
Accounts Payable Future Policy Benefits [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Fair Value	(1,505)	[2]	(648)	[2]
Notional Value/Payment Provision	$ 1,378	[2]	$ 649	[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 c) 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.