Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net income	$ 9,640	$ 9,015	$ 5,246
Net income (loss) attributable to noncontrolling interests	368	(13)	0
Net income attributable to Chubb	$ 9,272	$ 9,028	$ 5,246
Weighted-average shares outstanding	404,189,749	410,845,263	419,779,847
Share-based compensation plans	4,296,686	3,357,305	3,747,597
Adjusted weighted-average shares outstanding and assumed conversions	408,486,435	414,202,568	423,527,444
Basic earnings per share attributable to Chubb	$ 22.94	$ 21.97	$ 12.50
Diluted earnings per share attributable to Chubb	$ 22.70	$ 21.80	$ 12.39
Potential anti-dilutive share conversions	1,150,169	2,385,099	1,467,840