Investments (Reconciliation Of Available-For-Sale Securities From Cost Basis To Fair Value) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	$ 96,217	$ 94,295
ACL	(20)	0
Fair Value	102,606	105,200
Corporate Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
ACL	(20)
Fixed Maturity AFS Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	96,217	94,295
Gross unrealized gains	8,745	11,086
Gross unrealized losses	2,336	240
ACL	20
OTTI		(59)
Fair Value	102,606	105,200
Fixed Maturity AFS Securities [Member] \| Corporate Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	80,785	79,417
Gross unrealized gains	7,031	9,479
Gross unrealized losses	1,999	184
ACL	20
OTTI		(4)
Fair Value	85,797	88,716
Fixed Maturity AFS Securities [Member] \| U.S. Government Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	380	384
Gross unrealized gains	102	51
Fair Value	482	435
Fixed Maturity AFS Securities [Member] \| State And Municipal Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	4,797	4,778
Gross unrealized gains	1,123	1,113
Gross unrealized losses	14	7
Fair Value	5,906	5,884
Fixed Maturity AFS Securities [Member] \| Foreign Government Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	329	329
Gross unrealized gains	63	64
Gross unrealized losses	3
Fair Value	389	393
Fixed Maturity AFS Securities [Member] \| RMBS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	3,014	3,042
Gross unrealized gains	277	190
Gross unrealized losses	20	10
OTTI		(19)
Fair Value	3,271	3,241
Fixed Maturity AFS Securities [Member] \| CMBS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	1,089	1,038
Gross unrealized gains	39	45
Gross unrealized losses	9	1
OTTI		(1)
Fair Value	1,119	1,083
Fixed Maturity AFS Securities [Member] \| ABS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	5,259	4,810
Gross unrealized gains	59	62
Gross unrealized losses	232	18
OTTI		(35)
Fair Value	5,086	4,889
Fixed Maturity AFS Securities [Member] \| Hybrid And Redeemable Preferred Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	564	497
Gross unrealized gains	51	82
Gross unrealized losses	59	20
Fair Value	$ 556	$ 559

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Unrealized other than temporary impairment losses, investments, available-for-sale securities.

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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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