Investments (Gross Unrealized Losses Related To Available-For-Sale And Held-To-Maturity Investments) (Detail) - Fixed Maturities [Member] - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Available For Sale Securities [Abstract]
Less than 12 months, fair value	$ 276	$ 371
Less than 12 months, unrealized losses	(7)	(3)
12 months or longer, fair value	93	206
12 months or longer, unrealized losses	(12)	(8)
Total available-for-sale, fair value	369	577
Total available-for-sale, unrealized losses	(19)	(11)
U S Treasury And Government [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	66	148
Less than 12 months, unrealized losses	(1)	(1)
12 months or longer, fair value	0	79
12 months or longer, unrealized losses	0	(1)
Total available-for-sale, fair value	66	227
Total available-for-sale, unrealized losses	(1)	(2)
US States And Political Subdivisions [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	1	11
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	0	15
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	1	26
Total available-for-sale, unrealized losses	0	0
Foreign Government Debt [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	5
Less than 12 months, unrealized losses	0
12 months or longer, fair value	0
12 months or longer, unrealized losses	0
Total available-for-sale, fair value	5
Total available-for-sale, unrealized losses	0
Corporate Obligations [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	115	53
Less than 12 months, unrealized losses	(5)	(1)
12 months or longer, fair value	7	10
12 months or longer, unrealized losses	(1)	0
Total available-for-sale, fair value	122	63
Total available-for-sale, unrealized losses	(6)	(1)
Residential Mortgage Backed Agency [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	19	62
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	0	7
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	19	69
Total available-for-sale, unrealized losses	0	0
Residential Mortgage Backed Non Agency [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	3	0
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	10	11
12 months or longer, unrealized losses	(6)	(5)
Total available-for-sale, fair value	13	11
Total available-for-sale, unrealized losses	(6)	(5)
Commercial Mortgage Backed Securities [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	5	5
Less than 12 months, unrealized losses	0	0
12 months or longer, fair value	0	0
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	5	5
Total available-for-sale, unrealized losses	0	0
Collateralized Debt Obligations [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	46	44
Less than 12 months, unrealized losses	(1)	0
12 months or longer, fair value	76	77
12 months or longer, unrealized losses	(5)	(2)
Total available-for-sale, fair value	122	121
Total available-for-sale, unrealized losses	(6)	(2)
Other Asset Backed [Member]
Available For Sale Securities [Abstract]
Less than 12 months, fair value	16	48
Less than 12 months, unrealized losses	0	(1)
12 months or longer, fair value	0	7
12 months or longer, unrealized losses	0	0
Total available-for-sale, fair value	16	55
Total available-for-sale, unrealized losses	$ 0	$ (1)

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- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

No definition available.

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- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27337-111563

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This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References

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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months.

+ References

No definition available.

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+ References

No definition available.

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