Segments of Operations - Assets by segment (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Segment Reporting Information [Line Items]
Total assets	$ 30,294	$ 30,836
Property and Casualty Insurance
Segment Reporting Information [Line Items]
Total assets	25,704	25,913
Other
Segment Reporting Information [Line Items]
Total assets	$ 4,590	$ 4,923

Amount of asset recognized for present right to economic benefit.

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+ Details