Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 05, 2021	Jun. 30, 2020
Document and Entity Information
Document type	10-K
Document annual report	true
Document period end date	Dec. 31, 2020
Document transition report	false
Entity file number	001-10898
Registrant name	Travelers Companies, Inc.
Entity incorporation, state	MN
Entity tax identification number	41-0518860
Entity address, address line one	485 Lexington Avenue
Entity address, city	New York
Entity address, state	NY
Entity address, postal zip code	10017
City area code	917
Local phone number	778-6000
Title of 12(b) security	Common stock, without par value
Trading symbol	TRV
Security exchange name	NYSE
Well-known seasoned issuer	Yes
Voluntary filers	No
Entity current reporting status	Yes
Entity interactive data current	Yes
Filer category	Large Accelerated Filer
Entity small business	false
Entity emerging growth company	false
ICFR auditor attestation flag	true
Entity shell company	false
Entity public float			$ 28,802,579,969
Common stock shares outstanding		252,214,355
Central index key	0000086312
Current fiscal year end date	--12-31
Amendment flag	false
Document fiscal year focus	2020
Document fiscal period focus	FY