XML 13 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document And Entity Information - shares
 9 Months Ended
Jun. 30, 2018
Aug. 01, 2018
Document And Entity Information [Abstract]    
Entity Registrant Name IES Holdings, Inc.  
Entity Central Index Key 0001048268  
Document Type 10-Q  
Document Period End Date Jun. 30, 2018  
Amendment Flag false  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Current Fiscal Year End Date --09-30  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   21,205,536
Entity Well-known Seasoned Issuer No  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
TradingSymbol IESC