Consolidated Statements Of Shareholders' Equity - USD ($) $ in Millions	Total	Common Shares	Treasury Stock, Common	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Income Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Noncontrolling Interest
Noncontrolling interests											$ 0
Balance – beginning of year, net of tax at Dec. 31, 2020		$ 11,064	$ (3,644)	$ 9,815	$ 39,337	$ 52	$ 39,389	$ 2,869	$ (1,802)	$ 1,067
CB_Par Value Reduction		0		0
Treasury Stock, Retired, Cost Method, Amount		(79)	590		(511)
Common Shares repurchased			(4,861)
Net shares issued under employee share-based compensation plans			451	(179)
Stock Issued During Period, Value, Stock Options Exercised				(52)
Share-based compensation expense				286
Noncontrolling Interest, Increase from Business Combination				0
FundingDividendsDeclaredToRetainedEarnings				(1,392)
Net income attributable to Chubb	$ 8,525				8,525
Funding Dividends Declared From Additional Paid In Capital					1,392
Dividends declared on Common Shares					(1,392)
Other Comprehensive Income (Loss), Net of Tax	(2,141)							(2,141)
Balance – end of year, net of tax at Dec. 31, 2021	58,328	10,985	(7,464)	8,478	47,403	0	47,403	(1,074)	0	(1,074)
Net loss 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	58,328
CB_Par Value Reduction		0		0
Treasury Stock, Retired, Cost Method, Amount		(639)	4,983		(4,344)
Common Shares repurchased			(3,014)
Net shares issued under employee share-based compensation plans			382	(173)
Stock Issued During Period, Value, Stock Options Exercised				(43)
Share-based compensation expense				283
Noncontrolling Interest, Increase from Business Combination				0
FundingDividendsDeclaredToRetainedEarnings				(1,379)
Net income attributable to Chubb	5,246				5,246
Funding Dividends Declared From Additional Paid In Capital					1,379
Dividends declared on Common Shares					(1,379)
Other Comprehensive Income (Loss), Net of Tax	(9,111)							(9,111)
Balance – end of year, net of tax at Dec. 31, 2022	50,519	10,346	(5,113)	7,166	48,305	$ 0	$ 48,305	(10,185)	$ 0	$ (10,185)
Net loss attributable to noncontrolling interests	0										0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest											0
Noncontrolling interests	0										0
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value											0
Total shareholders’ equity	50,519
CB_Par Value Reduction		(9,759)		9,759
Treasury Stock, Retired, Cost Method, Amount		(346)	2,869		(2,523)
Common Shares repurchased			(2,478)
Net shares issued under employee share-based compensation plans			322	(192)
Stock Issued During Period, Value, Stock Options Exercised				(20)
Share-based compensation expense				322
Noncontrolling Interest, Increase from Business Combination				31
FundingDividendsDeclaredToRetainedEarnings				(1,401)
Net income attributable to Chubb	9,028				9,028
Funding Dividends Declared From Additional Paid In Capital					1,401
Dividends declared on Common Shares					(1,401)
Other Comprehensive Income (Loss), Net of Tax	3,361							3,376
Balance – end of year, net of tax at Dec. 31, 2023	59,507	$ 241	$ (4,400)	$ 15,665	$ 54,810			$ (6,809)
Net loss attributable to noncontrolling interests	(13)										(13)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest											(15)
Noncontrolling interests	4,184										4,184
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value											$ 4,212
Total shareholders’ equity	$ 63,691