Cover
| Cover | Apr. 16, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Apr. 16, 2023 |
| Entity Registrant Name | OTTER TAIL CORPORATION |
| Entity Tax Identification Number | 27-0383995 |
| Entity Address, Address Line One | 215 South Cascade Street, P.O. Box 496 |
| Entity Address, City or Town | Fergus Falls |
| Entity Address, State or Province | MN |
| Entity Address, Postal Zip Code | 56538-0496 |
| City Area Code | 866 |
| Local Phone Number | 410-8780 |
| Title of 12(b) Security | Common Shares, par value $5.00 per share |
| Trading Symbol | OTTR |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001466593 |
| Amendment Flag | false |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity File Number | 0-53713 |
| Entity Incorporation, State or Country Code | MN |