Investments - Investments - ACL on Fixed Maturities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	$ 14	$ 18	$ 16	$ 21
Credit losses on fixed maturities where credit losses were not previously recorded	0	1	0	1
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			(2)	1
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Writeoff			0	4
Corporate
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance		6	3	9
Credit losses on fixed maturities where credit losses were not previously recorded		0	0	0
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			(3)	1
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Writeoff			0	4
CMBS
Debt Securities, Available-for-sale, Allowance for Credit Loss [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss, Beginning Balance	14	12	13	12
Credit losses on fixed maturities where credit losses were not previously recorded	$ 0	$ 1	0	1
Net increases (decreases) in allowance on fixed maturities that had an allowance in a previous period			1	0
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Writeoff			$ 0	$ 0

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
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Section 50
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-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
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Amount of expense (reversal of expense) for 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), not intended to be sold and not more likely than not will be required to sell before recovery of amortized cost basis, with previously recorded allowance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147476148/220-40-50-22

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Amount of writeoff 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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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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 326
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-9

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