Investments - Composition of Current and Past Due Mortgage Loans on Real Estate (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses	$ (165)	$ (152)
Unamortized premium (discount)	98	77
Mark-to-market gains (losses)	(34)	(31)
Total carrying value	22,230	21,083
Loans with fair value option in non-accrual, amortized cost	30	30
Loans with fair value option in non-accrual	20	21
Loans with fair value option, 90 days past due and still accruing	0	0
Current
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	22,057	20,954
30 to 59 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	69	77
60 to 89 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	44	33
90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	161	125
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses	(97)	(99)
Unamortized premium (discount)	(5)	(6)
Mark-to-market gains (losses)	(34)	(31)
Total carrying value	17,570	17,472
Commercial \| Current
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	17,670	17,567
Commercial \| 30 to 59 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	0	6
Commercial \| 60 to 89 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	0	0
Commercial \| 90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	36	35
Residential mortgage loans on real estate
Loans and Leases Receivable Disclosure [Line Items]
Allowance for credit losses	(68)	(53)
Unamortized premium (discount)	103	83
Mark-to-market gains (losses)	0	0
Total carrying value	4,660	3,611
Residential mortgage loans on real estate \| Current
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	4,387	3,387
Residential mortgage loans on real estate \| 30 to 59 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	69	71
Residential mortgage loans on real estate \| 60 to 89 days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	44	33
Residential mortgage loans on real estate \| 90 or more days past due
Loans and Leases Receivable Disclosure [Line Items]
Mortgage loans on real estate, gross	$ 125	$ 90

Fair Value, Option, Loans Held As Assets, Amortized Cost, Aggregate Amount In Nonaccrual Status

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- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

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- Definition

This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

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This item represents the aggregate fair value of loans held as assets that are in nonaccrual status for which the fair value option has been elected, if the entity's policy is to recognize interest income separately from other changes in fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

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

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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
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-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

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- Definition

Amount of unamortized purchase premium (discount) on financing receivable. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
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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.

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