| Document and Entity Information | Jul. 07, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jul. 07, 2022 |
| Entity Registrant Name | NEOGEN CORPORATION |
| Entity Incorporation, State or Country Code | MI |
| Entity File Number | 0-17988 |
| Entity Tax Identification Number | 38-2367843 |
| Entity Address, Address Line One | 620 Lesher Place |
| Entity Address, City or Town | Lansing |
| Entity Address, State or Province | MI |
| Entity Address, Postal Zip Code | 48912 |
| City Area Code | 517 |
| Local Phone Number | 372-9200 |
| Written Communications | true |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000711377 |
| Title of 12(b) Security | Common Stock, $0.16 par value per share |
| Trading Symbol | NEOG |
| Security Exchange Name | NASDAQ |
