Investments (Reconciliation Of Available-For-Sale Securities From Cost Basis To Fair Value) (Details) - Fixed Maturity AFS Securities [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	$ 95,183	$ 93,307
Gross Unrealized Gains	8,364	10,633
Gross Unrealized Losses	2,252	226
OTTI	18	(59)
Fair Value	101,277	103,773
Corporate Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	80,196	78,875
Gross Unrealized Gains	6,706	9,071
Gross Unrealized Losses	1,919	172
OTTI	18	(5)
Fair Value	84,965	87,779
ABS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	5,252	4,803
Gross Unrealized Gains	59	62
Gross Unrealized Losses	231	17
OTTI		(35)
Fair Value	5,080	4,883
U.S. Government Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	352	355
Gross Unrealized Gains	94	48
Fair Value	446	403
Foreign Government Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	325	326
Gross Unrealized Gains	63	62
Gross Unrealized Losses	3
Fair Value	385	388
RMBS [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	2,794	2,820
Gross Unrealized Gains	258	179
Gross Unrealized Losses	19	9
OTTI		(18)
Fair Value	3,033	3,008
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
State And Municipal Bonds [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	4,622	4,605
Gross Unrealized Gains	1,095	1,087
Gross Unrealized Losses	13	7
Fair Value	5,704	5,685
Hybrid And Redeemable Preferred Securities [Member]
Amortized cost, gross unrealized gains, losses, OTTI and fair value of AFS securities
Amortized Cost	553	485
Gross Unrealized Gains	50	79
Gross Unrealized Losses	58	20
Fair Value	$ 545	$ 544

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- Definition

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

+ References

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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