Document and Entity Information - SFr / shares	6 Months Ended
	Jun. 30, 2019	Jul. 17, 2019	Dec. 31, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	Chubb Ltd
Entity Central Index Key	0000896159
Document Type	10-Q
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Entity File Number	1-11778
Entity Incorporation, State or Country Code	V8
Entity Tax Identification Number	98-0091805
Entity Address, Address Line One	Baerengasse 32
Entity Address, City or Town	Zurich
Entity Address, Country	CH
Entity Address, Postal Zip Code	8001
Country Region	41
City Area Code	(0)43
Local Phone Number	456 76 00
Title of 12(b) Security	Common Shares, par value CHF 24.15 per share
Trading Symbol	CB
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Common Shares, par value	SFr 24.15		SFr 24.15
Entity Shell Company	false
Common Shares Outstanding		455,749,479
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Small Business	false
Entity Emerging Growth Company	false
Document Transition Report	false