Fair Value Measurements - Gains or losses recorded related to fair value option (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	$ 74	$ 283	$ 173	$ 469
Total liabilities
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	1	0	1	(2)
Policyholder contract deposits
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	1	0	1	(2)
Total assets
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	73	283	172	471
Other bond securities
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	77	101	88	240
Alternative investments
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	$ (4)	$ 182	$ 84	$ 231

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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