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]	Parent	Noncontrolling Interest
Total shareholders' equity		$ 241	$ (4,400)	$ 15,665	$ 54,810	$ (6,809)		$ 4,184
Treasury Stock, Retired, Cost Method, Amount		0	0		0
Common Shares repurchased			(316)
Net shares issued under employee share-based compensation plans			255
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				(159)
Exercise of stock options				(19)
Share-based compensation expense				82
Adjustments to Additional Paid in Capital, Other				(31)
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)
Net increase (decrease) due to consolidation, deconsolidation, and other transactions								(411)
Net income attributable to noncontrolling interests	151							151
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest								(28)
Total shareholders' equity	64,431	241	(4,461)	15,188	56,953	(7,386)	$ 60,535	3,896
Noncontrolling interests	4,373
Total shareholders' equity	68,394	235	(3,524)	14,393	61,561	(8,644)		4,373
Balance – beginning of period, net of tax at Dec. 31, 2024	64,021
Treasury Stock, Retired, Cost Method, Amount		(4)	(1,942)		(1,939)
Common Shares repurchased			(385)
Net shares issued under employee share-based compensation plans			168
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				(146)
Exercise of stock options				1
Share-based compensation expense				94
Adjustments to Additional Paid in Capital, Other				0
Funding of dividends declared to Retained earnings				(366)
Net income attributable to Chubb	1,331				1,331
Funding of dividends declared from Additional paid-in capital					366
Dividends declared on Common Shares					(366)
Other Comprehensive Income (Loss), Net of Tax	1,004					1,009
Balance – end of period, net of tax at Mar. 31, 2025	65,726
Net increase (decrease) due to consolidation, deconsolidation, and other transactions								649
Net income attributable to noncontrolling interests	12							12
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest								(5)
Noncontrolling interests	5,029
Total shareholders' equity	$ 70,755	$ 231	$ (1,799)	$ 13,976	$ 60,953	$ (7,635)	$ 65,726	$ 5,029