Cover
| Cover | Apr. 02, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Amendment Flag | true |
| Amendment Description | This Form 8-K/A amends and restates the original Current Report on Form 8-K that was filed on April 7, 2021, in order to correct the original Current Report’s description of certain covenants contained in the 2021 Credit Agreement, as marked below. The descriptions contained in this Form 8-K/A and the original Current Report are subject to the full terms and conditions of the credit facility as set forth in the 2021 Credit Agreement. A copy of the 2021 Credit Agreement is filed as Exhibit 10.1 to the original Current Report and is incorporated by reference herein. |
| Document Period End Date | Apr. 2, 2021 |
| Entity File Number | 1-16191 |
| Entity Registrant Name | TENNANT COMPANY |
| Entity Central Index Key | 0000097134 |
| Entity Tax Identification Number | 41-0572550 |
| Entity Incorporation, State or Country Code | MN |
| Entity Address, Address Line One | 10400 Clean Street |
| Entity Address, City or Town | Eden Prairie, |
| Entity Address, State or Province | MN |
| Entity Address, Postal Zip Code | 55344 |
| City Area Code | 763 |
| Local Phone Number | 540-1200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.375 per share |
| Trading Symbol | TNC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |