Derivatives - Gains (losses) included in the Statement of Earnings for changes in the fair value of derivatives (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives not designated as hedges, gains (losses) included in net earnings	$ (8)	$ 11	$ (8)	$ 20
Earnings (losses) on derivatives	(8)	8	(10)	12
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Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives not designated as hedges, gains (losses) included in net earnings	(6)	1	(16)	2
Fixed maturities with embedded derivatives \| Income Statement Location [Axis]: us-gaap:NetInvestmentIncome
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives not designated as hedges, gains (losses) included in net earnings	0	4	0	6
Total return swap \| Income Statement Location [Axis]: us-gaap:OtherCostAndExpenseOperating
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivatives not designated as hedges, gains (losses) included in net earnings	(2)	6	8	12
Designated as hedging instrument \| Interest rate swaps \| Income Statement Location [Axis]: us-gaap:NetInvestmentIncome
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification from accumulated other comprehensive income	$ 0	$ (3)	$ (2)	$ (8)

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Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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