Document and Entity Information	12 Months Ended
	Dec. 31, 2017 USD ($) shares
Document and Entity Information [Abstract]
Entity Registrant Name	TIMKEN CO
Entity Central Index Key	0000098362
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float | $	$ 3,097,156,335
Entity Common Stock, Shares Outstanding | shares	77,882,884