DEI Document - shares	9 Months Ended
	Jun. 30, 2020	Aug. 05, 2020
Entity Information [Line Items]
Entity File Number	001-13783
Entity Registrant Name	IES Holdings, Inc.
Document Period End Date	Jun. 30, 2020
Document Quarterly Report	true
Document Transition Report	false
Entity Central Index Key	0001048268
Entity Incorporation, State or Country Code	DE
Document Type	10-Q
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--09-30
Entity Filer Category	Accelerated Filer
Entity Tax Identification Number	76-0542208
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Address, Address Line One	5433 Westheimer Road
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77056
City Area Code	713
Local Phone Number	860-1500
Entity Common Stock, Shares Outstanding		21,048,572
Common Stock, par value $0.01 per share
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	IESC
Security Exchange Name	NASDAQ
Rights to Purchase Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	Rights to Purchase Preferred Stock
Trading Symbol	IESC
Security Exchange Name	NASDAQ