XML 48 R1.htm IDEA: XBRL DOCUMENT v3.2.0.727
Document and Entity Information - USD ($)
 12 Months Ended
May. 31, 2015
Jun. 30, 2015
Nov. 30, 2014
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date May 31, 2015    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Trading Symbol NEOG    
Entity Registrant Name NEOGEN CORP    
Entity Central Index Key 0000711377    
Current Fiscal Year End Date --05-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   37,134,369  
Entity Public Float     $ 1,638,000,000