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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Investments (Reconciliation Of Available-For-Sale Securities From Cost Basis To Fair Value) (Details) - USD ($) $ in Millions	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	$ 106,752		$ 103,021
Allowance for Credit Losses	17	$ 9	13	$ 12	$ 21
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	120,794		121,111
Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	106,752		103,021
Gross Unrealized Gains	14,431		18,287
Gross Unrealized Losses	372		184
Allowance for Credit Losses	17		13
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	120,794		121,111
Corporate Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Allowance for Credit Losses	16	8	12	11	19
Corporate Bonds [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	88,020		85,625
Gross Unrealized Gains	12,418		15,947
Gross Unrealized Losses	297		136
Allowance for Credit Losses	16		12
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	100,125		101,424
ABS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Allowance for Credit Losses					1
ABS [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	8,180		7,035
Gross Unrealized Gains	147		158
Gross Unrealized Losses	31		15
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	8,296		7,178
U.S. Government Bonds [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	357		369
Gross Unrealized Gains	55		81
Gross Unrealized Losses	2		1
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	410		449
Foreign Government Bonds [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	446		380
Gross Unrealized Gains	63		86
Gross Unrealized Losses	7		1
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	502		465
RMBS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Allowance for Credit Losses	1	$ 1	1	$ 1	$ 1
RMBS [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	2,481		2,551
Gross Unrealized Gains	232		289
Gross Unrealized Losses	3		1
Allowance for Credit Losses	1		1
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	2,709		2,838
CMBS [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	1,519		1,380
Gross Unrealized Gains	76		115
Gross Unrealized Losses	10
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	1,585		1,495
State And Municipal Bonds [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	5,324		5,145
Gross Unrealized Gains	1,334		1,517
Gross Unrealized Losses	10
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	6,648		6,662
Hybrid And Redeemable Preferred Securities [Member] \| Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	425		536
Gross Unrealized Gains	106		94
Gross Unrealized Losses	12		30
Fixed maturity available-for-sale securities, at fair value (amortized cost: 2021 - $105,530; 2020 - $103,021; allowance for credit losses: 2021 - $9; 2020 - $13)	$ 519		$ 600