Investments - Additional Information (Details) $ in Millions	3 Months Ended
Mar. 31, 2026 USD ($) loan	Dec. 31, 2025 USD ($) loan
Net Investment Income [Line Items]
Percentage of investment portfolio by which no other industry group exceeded	10.00%
Percentage of stockholders' equity by which no single issuer of fixed maturity securities exceeded	10.00%
Commercial mortgage loans	$ 6,351	$ 6,363
Office
Net Investment Income [Line Items]
Commercial mortgage loans	1,266	1,292
Industrial
Net Investment Income [Line Items]
Commercial mortgage loans	$ 1,464	$ 1,454
Financing Receivables More Then 90 Days Past Due \| Office
Net Investment Income [Line Items]
Number of mortgage loan \| loan	1	1
Commercial mortgage loans	$ 6	$ 6
Financing Receivables More Then 90 Days Past Due \| Industrial
Net Investment Income [Line Items]
Number of mortgage loan \| loan	2
Commercial mortgage loans	$ 1
Financing Receivables 31 To 60 Days Past Due \| Industrial
Net Investment Income [Line Items]
Number of mortgage loan \| loan		2
Commercial mortgage loans		$ 3
Finance and insurance \| Fixed maturity securities:
Net Investment Income [Line Items]
Percent of investment portfolio, greater than 10%	26.00%
Utilities \| Fixed maturity securities:
Net Investment Income [Line Items]
Percent of investment portfolio, greater than 10%	15.00%
Consumer—non-cyclical \| Fixed maturity securities:
Net Investment Income [Line Items]
Percent of investment portfolio, greater than 10%	14.00%

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Concentration risk of greater than or equal to 10% of fixed maturity securities.

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- Definition

Investment disclosure of credit risk exposure of fixed maturity securities in a single issuer as measured by a stated percentage of the Company's stockholders' equity, by which no industry group exceeded other than those identified.

+ References

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Percentage Of Stockholders' Equity By Which No Single Issuer Of Fixed Maturity Securities Exceeded

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- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-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 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 50
-Paragraph 5
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-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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