Derivative Financial Instruments (Schedule Of Gains And Losses Of Derivative Financial Instruments Without Hedge Designation) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		$ (55)	$ (5)	$ (115)
Equity Contract [Member] | Equity Futures - Long [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(8)	(3)	(8)	(6)
Equity Options - Purchased [Member] | Equity Contract [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	16	(7)	7	(10)
Equity Options - Written [Member] | Equity Contract [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(18)	10	(11)	15
Equity Futures - Short [Member] | Equity Contract [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	6	(1)	5	(4)
Foreign Exchange [Member] | Currency Forwards - Short [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	5	(8)	5	(9)
Foreign Exchange [Member] | Currency Options- Short [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		1		(1)
Foreign Exchange [Member] | Currency Forwards - Long [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(2)	2	(2)
Interest Rate Risks [Member] | Options On Government Securities - Short [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(66)		(66)
Interest Rate Risks [Member] | Interest Rate Futures - Long [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		4		(14)
Interest Rate Risks [Member] | Interest Rate Futures- Short [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	2	14	2	14
Interest Rate Risks [Member] | Credit Default Swaps - Sold Protection [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(3)		(3)
Interest Rate Risks [Member] | Credit Default Swaps - Purchased Protection [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	2		2
Other Contract [Member] | Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1)		(2)	(2)
Interest Rate Swaps [Member] | Investment Gains (Losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net				(44)
Commodity Forwards - Short [Member] | Investment Gains (Losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net				13
Credit Default Swaps - Purchased Protection [Member] | Investment Gains (Losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(1)		(1)
Forward Commitments For Mortgage-Backed Securities [Member] | Investment Gains (Losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1		1
Currency Forwards - Short [Member] | Investment Gains (Losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net			(1)
Net Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1)	(54)	(5)	(83)
Investment Gains (Losses) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 1	$ (1)		$ (32)