Investments - Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities	$ 14	$ (46)
Net of tax
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	13	(33)
Realized — impairments	(2)	(4)
Realized gains (losses) on securities	11	(37)
Change in unrealized	9	84
Total pretax
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	16	(41)
Realized — impairments	(2)	(5)
Realized gains (losses) on securities	14	(46)
Change in unrealized	11	107
Fixed maturities:
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	(4)	(23)
Realized — impairments	(2)	(5)
Realized gains (losses) on securities	(6)	(28)
Change in unrealized	11	107
Equity securities
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	20	(18)
Realized — impairments	0	0
Realized gains (losses) on securities	20	(18)
Change in unrealized	0	0
Mortgage loans and other investments
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	0	0
Realized — impairments	0	0
Realized gains (losses) on securities	0	0
Change in unrealized	0	0
Tax effects
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	(3)	8
Realized — impairments	0	1
Realized gains (losses) on securities	(3)	9
Change in unrealized	$ (2)	$ (23)

Change in unrealized appreciation depreciation.

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- Definition

Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments.

+ References

No definition available.

+ Details

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- Definition

Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

+ References

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- Definition

Amount of realized gain (loss) on investment in marketable security.

+ References

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- Definition

Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 8A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481830/320-10-45-8A

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