Investments - Investments - ACL on Fixed Maturities (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	$ 13	$ 4	$ 1	$ 23
Credit losses on fixed maturities where credit losses were not previously recorded	6	0	18	2
Reduction due to sales	(1)	0	(1)	(15)
Reduction due to intent to sell	(3)	0	(3)	0
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			0	(6)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	15	4	15	4
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	8	4	1	23
Credit losses on fixed maturities where credit losses were not previously recorded	0	0	8	2
Reduction due to sales	0	0	0	(15)
Reduction due to intent to sell	0	0	0	0
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			(1)	(6)
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	8	$ 4	8	$ 4
Foreign Govt./Govt. Agencies
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	4		0
Credit losses on fixed maturities where credit losses were not previously recorded	0		3
Reduction due to sales	(1)		(1)
Reduction due to intent to sell	(3)		(3)
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			1
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	0		0
CMBS
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	1		0
Credit losses on fixed maturities where credit losses were not previously recorded	6		7
Reduction due to sales	0		0
Reduction due to intent to sell	0		0
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			0
Debt Securities, Available-for-sale, Allowance for Credit Loss, Ending Balance	$ 7		$ 7

Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922900-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 9
-Subparagraph (i)
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922900-210455

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27161-111563

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

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Amount of expense for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), for which no credit loss was previously recorded.

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