Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 21, 2017
Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Trading Symbol	CB
Entity Registrant Name	Chubb Ltd
Entity Central Index Key	0000896159
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Common Shares Outstanding		465,416,079