Acquisitions (Acquisition operations) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Business Acquisition [Line Items]
Total revenues	$ 14,849	$ 13,853	$ 41,578	$ 36,743
Net income	2,490	2,040	7,000	5,725
Net loss attributable to Chubb	$ 2,324	$ 2,043	$ 6,697	5,728
Huatai Group
Business Acquisition [Line Items]
Total revenues				389
Net income				(11)
Net loss attributable to Chubb				$ (9)