Warranty (Details 2)	9 Months Ended
Sep. 30, 2020
Product Warranties Disclosures [Abstract]
Machine warranty, range minimum (in years)	1 year
Period of time following a sale the majority of claims are paid, range minimum (in years)	6 months

The typical range of period of time following a sale the majority of warranty claims are paid out on the low end of the range.

No definition available.

Name:	tnc_Periodoftimefollowingasalethemajorityofclaimsarepaidmin
Namespace Prefix:	tnc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration