v3.10.0.1
Document And Entity Information - USD ($)
12 Months Ended
Jun. 30, 2018
Aug. 20, 2018
Dec. 29, 2017
Document Information [Line Items]      
Entity Registrant Name TWIN DISC INC    
Entity Central Index Key 0000100378    
Trading Symbol twin    
Current Fiscal Year End Date --06-30    
Entity Filer Category Accelerated Filer    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer No    
Entity Common Stock, Shares Outstanding (in shares)   11,523,273  
Entity Public Float     $ 223,519,036
Document Type 10-K    
Document Period End Date Jun. 30, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Amendment Flag false