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)
Par value reduction		(9,759)		(9,759)
Treasury Stock, Retired, Cost Method, Amount		(346)	(2,869)		(2,523)
Common Shares repurchased			(1,152)
Net shares issued under employee share-based compensation plans			(222)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				(206)
Exercise of stock options				(13)
Share-based compensation expense				155
Adjustments to Additional Paid in Capital, Other				0
Funding of dividends declared to Retained earnings				(698)
Net income attributable to Chubb	$ 3,685				3,685
Funding of dividends declared from Additional paid-in capital					698
Dividends declared on Common Shares					(698)
Other Comprehensive Income (Loss), Net of Tax	363					363
Balance – end of period, net of tax at Jun. 30, 2023	52,875	241	(3,174)	16,163	49,467	(9,822)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests							0
Net income (loss) attributable to noncontrolling interests	0						0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest							0
Other							0
Noncontrolling interests							0
Balance – beginning of period, net of tax at Mar. 31, 2023		10,346	(5,341)	6,680	50,197	(8,895)
Par value reduction		(9,759)		(9,759)
Treasury Stock, Retired, Cost Method, Amount		(346)	(2,869)		(2,523)
Common Shares repurchased			(724)
Net shares issued under employee share-based compensation plans			(22)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				5
Exercise of stock options				0
Share-based compensation expense				73
Adjustments to Additional Paid in Capital, Other				0
Funding of dividends declared to Retained earnings				(354)
Net income attributable to Chubb	1,793				1,793
Funding of dividends declared from Additional paid-in capital					354
Dividends declared on Common Shares					(354)
Other Comprehensive Income (Loss), Net of Tax	(927)					(927)
Balance – end of period, net of tax at Jun. 30, 2023	52,875	241	(3,174)	16,163	49,467	(9,822)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests							0
Net income (loss) attributable to noncontrolling interests	0						0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest							0
Other							0
Noncontrolling interests							0
Total shareholders' equity	52,875
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)
Par value reduction		0		0
Treasury Stock, Retired, Cost Method, Amount		(6)	(2,527)		(2,521)
Common Shares repurchased			(886)
Net shares issued under employee share-based compensation plans			(278)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				(142)
Exercise of stock options				(19)
Share-based compensation expense				172
Adjustments to Additional Paid in Capital, Other				(31)
Funding of dividends declared to Retained earnings				(719)
Net income attributable to Chubb	4,373				4,373
Funding of dividends declared from Additional paid-in capital					719
Dividends declared on Common Shares					(719)
Other Comprehensive Income (Loss), Net of Tax	(1,566)					(1,495)
Balance – end of period, net of tax at Jun. 30, 2024	61,038	235	(2,481)	14,926	56,662	(8,304)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests							(707)
Net income (loss) attributable to noncontrolling interests	137						137
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest							(71)
Other							(6)
Noncontrolling interests							3,896
Balance – beginning of period, net of tax at Mar. 31, 2024		241	(4,461)	15,188	56,953	(7,386)
Par value reduction		0		0
Treasury Stock, Retired, Cost Method, Amount		(6)	(2,527)		(2,521)
Common Shares repurchased			(570)
Net shares issued under employee share-based compensation plans			(23)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				17
Exercise of stock options				0
Share-based compensation expense				90
Adjustments to Additional Paid in Capital, Other				0
Funding of dividends declared to Retained earnings				(369)
Net income attributable to Chubb	2,230				2,230
Funding of dividends declared from Additional paid-in capital					369
Dividends declared on Common Shares					(369)
Other Comprehensive Income (Loss), Net of Tax	(961)					(918)
Balance – end of period, net of tax at Jun. 30, 2024	61,038	$ 235	$ (2,481)	$ 14,926	$ 56,662	$ (8,304)
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests							(296)
Net income (loss) attributable to noncontrolling interests	(14)						(14)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest							(43)
Other							(6)
Noncontrolling interests	3,537						$ 3,537
Total shareholders' equity	$ 64,575