Investments - Investments - ACL on Mortgages (Details) - Commercial Loan [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	$ (41)	$ (36)	$ (36)	$ (29)
Current period provision	5	0	10	7
Financing Receivable, Allowance for Credit Loss	$ (46)	$ (36)	$ (46)	$ (36)

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (1)
-Publisher SEC

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
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-Publisher SEC

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (c)
-Publisher SEC

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant