Fair Value Measurements - Gains or losses recorded related to fair value option (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	$ 99	$ 186
Total liabilities
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	0	(2)
Policyholder contract deposits
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	0	(2)
Total assets
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	99	188
Other bond securities
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	11	139
Alternative investments
Fair Value, Option, Quantitative Disclosures
Total gain (loss)	$ 88	$ 49

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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