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, 2022	Mar. 31, 2021
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized gains (losses) on securities	$ (15)	$ 77
Net of tax
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	(14)	60
Realized — impairments	2	1
Realized gains (losses) on securities	(12)	61
Change in unrealized	(245)	(35)
Total pretax
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	(17)	76
Realized — impairments	2	1
Realized gains (losses) on securities	(15)	77
Change in unrealized	(311)	(44)
Fixed maturities
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	(4)	(1)
Realized — impairments	2	1
Realized gains (losses) on securities	(2)	0
Change in unrealized	(311)	(44)
Equity securities
Realized gains (losses) and changes in unrealized appreciation (depreciation) related to fixed maturity and equity security investments
Realized before impairments	(13)	77
Realized — impairments	0	0
Realized gains (losses) on securities	(13)	77
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	(16)
Realized — impairments	0	0
Realized gains (losses) on securities	3	(16)
Change in unrealized	$ 66	$ 9

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, excluding other-than-temporary impairment (OTTI).

+ References

No definition available.

+ Details

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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://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 8A
-URI http://asc.fasb.org/extlink&oid=124260329&loc=SL6284422-111562

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