Fair Value Measurements - Gains or losses recorded related to fair value option (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	$ 80	$ 221	$ 253	$ 690
Total liabilities
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	5	0	6	(2)
Policyholder contract deposits
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	5	0	6	(2)
Total assets
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	75	221	247	692
Other bond securities
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	(122)	157	(34)	397
Alternative investments
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	$ 197	$ 64	$ 281	$ 295

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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