Acquisitions (Acquisition operations) (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Total revenues			$ 55,753	$ 49,735	$ 43,097
Net income			9,640	9,015	5,246
Net loss attributable to Chubb			$ 9,272	$ 9,028	$ 5,246
Huatai Group [Member]
Business Acquisition [Line Items]
Total revenues	$ 739
Net income	(30)
Net loss attributable to Chubb	$ (17)
Cigna's Life Insurance Business in Asian Markets
Business Acquisition [Line Items]
Total revenues		$ 1,507
Net loss attributable to Chubb		$ 140