XML 14 R1.htm IDEA: XBRL DOCUMENT v3.5.0.2
Document and Entity Information - USD ($)
 12 Months Ended
Sep. 30, 2016
Nov. 25, 2016
Mar. 31, 2016
Document Information [Line Items]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Sep. 30, 2016    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY    
Trading Symbol GENC    
Entity Registrant Name GENCOR INDUSTRIES INC    
Entity Central Index Key 0000064472    
Current Fiscal Year End Date --09-30    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Smaller Reporting Company    
Entity Public Float     $ 97,608,600
Common Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   12,111,079  
Class B Stock [Member]      
Document Information [Line Items]      
Entity Common Stock, Shares Outstanding   2,263,857