Consolidated Statements Of Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock [Member]	Treasury Stock, Common	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest
Noncontrolling interests							$ 0
Balance – beginning of period, net of tax at Dec. 31, 2022		$ 10,346	$ (5,113)	$ 7,166	$ 48,305	$ (10,185)
Noncontrolling Interest, Increase from Business Combination				0
Common Shares repurchased			(428)
Net shares issued under employee share-based compensation plans			200	(211)
Exercise of stock options				(13)
Share-based compensation expense				82
Funding of dividends declared to Retained earnings				(344)
Net income attributable to Chubb	$ 1,892				1,892
Funding of dividends declared from Additional paid-in capital					344
Dividends declared on Common Shares					(344)
Other Comprehensive Income (Loss), Net of Tax	1,290					1,290
Balance – end of period, net of tax at Mar. 31, 2023	52,987	10,346	(5,341)	6,680	50,197	(8,895)
Net income attributable to noncontrolling interests	0						0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest							0
Noncontrolling interests							0
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value							0
Total shareholders' equity	52,987
Noncontrolling interests	4,184						4,184
Total shareholders' equity	63,691
Balance – beginning of period, net of tax at Dec. 31, 2023	59,507	241	(4,400)	15,665	54,810	(6,809)
Noncontrolling Interest, Increase from Business Combination				(31)
Common Shares repurchased			(316)
Net shares issued under employee share-based compensation plans			255	(159)
Exercise of stock options				(19)
Share-based compensation expense				82
Funding of dividends declared to Retained earnings				(350)
Net income attributable to Chubb	2,143				2,143
Funding of dividends declared from Additional paid-in capital					350
Dividends declared on Common Shares					(350)
Other Comprehensive Income (Loss), Net of Tax	(605)					(577)
Balance – end of period, net of tax at Mar. 31, 2024	60,535	$ 241	$ (4,461)	$ 15,188	$ 56,953	$ (7,386)
Net income attributable to noncontrolling interests	151						151
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest							(28)
Noncontrolling interests	3,896						3,896
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value							$ (411)
Total shareholders' equity	$ 64,431