Acquisitions (Acquisition operations) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Business Acquisition [Line Items]
Total revenues	$ 13,853	$ 12,122	$ 36,743	$ 31,654
Net income	2,040	792	5,725	3,935
Net loss attributable to Chubb	$ 2,043	$ 792	5,728	3,935
Huatai Group
Business Acquisition [Line Items]
Total revenues			389
Net income			(11)
Net loss attributable to Chubb			$ (9)
Cigna's Life Insurance Business in Asia-Pacific Markets [Member]
Business Acquisition [Line Items]
Total revenues				681
Net loss attributable to Chubb				$ 17