XML 11 R1.htm IDEA: XBRL DOCUMENT v3.6.0.2
Document and Entity Information - shares
 3 Months Ended
Dec. 31, 2016
Feb. 01, 2017
Document Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Dec. 31, 2016  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q1  
Trading Symbol GENC  
Entity Registrant Name GENCOR INDUSTRIES INC  
Entity Central Index Key 0000064472  
Current Fiscal Year End Date --09-30  
Entity Filer Category Accelerated Filer  
Common Stock [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   12,113,079
Class B Stock [Member]    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   2,263,857