Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 08, 2019	Jun. 30, 2018
Document and Entity Information
Registrant name	TRAVELERS COMPANIES, INC.
Central index key	0000086312
Document type	10-K
Document period end date	Dec. 31, 2018
Amendment flag	false
Current fiscal year end date	--12-31
Current reporting status	Yes
Well-known seasoned issuer	Yes
Voluntary filers	No
Filer category	Large Accelerated Filer
Entity emerging growth company	false
Entity small business	false
Entity shell company	false
Common stock shares outstanding		263,391,034
Document fiscal year focus	2018
Document fiscal period focus	FY
Entity public float			$ 32,661,754,275