Cover Page - USD ($)	12 Months Ended
	May 31, 2024	Jun. 30, 2024	Nov. 30, 2023
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	May 31, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--05-31
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Entity Registrant Name	NEOGEN CORPORATION
Entity Central Index Key	0000711377
Trading Symbol	NEOG
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Small Business	false
Document Annual Report	true
Document Transition Report	false
Entity Public Float			$ 3,254,614,597
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		216,694,486
Entity File Number	0-17988
Title of 12(g) Security	Common Stock, $0.16 par value per share
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-2367843
Entity Address, Address Line One	620 Lesher Place
Entity Address, State or Province	MI
Local Phone Number	372-9200
Entity Address, City or Town	Lansing
City Area Code	517
Entity Address, Postal Zip Code	48912
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Auditor Name	BDO USA, P.C.
Auditor Firm ID	243
Auditor Location	Grand Rapids, MI