| Document and Entity Information | Apr. 06, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | LINDSAY CORP |
| Security Exchange Name | NYSE |
| Amendment Flag | false |
| Entity Central Index Key | 0000836157 |
| Document Type | 8-K |
| Document Period End Date | Apr. 6, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 1-13419 |
| Entity Tax Identification Number | 47-0554096 |
| Entity Address, Address Line One | 18135 Burke Street |
| Entity Address, Address Line Two | Suite 100 |
| Entity Address, City or Town | Omaha |
| Entity Address, State or Province | NE |
| Entity Address, Postal Zip Code | 68022 |
| City Area Code | (402) |
| Local Phone Number | 829-6800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $1.00 par value |
| Trading Symbol | LNN |
| Entity Emerging Growth Company | false |
