| Cover | 3 Months Ended |
| Dec. 31, 2020 | |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Feb. 5, 2021 |
| Entity Registrant Name | IES Holdings, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-13783 |
| Entity Tax Identification Number | 76-0542208 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001048268 |
| Amendment Flag | false |
| Common Stock [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | IESC |
| Security Exchange Name | NASDAQ |
| Preferred Stock [Member] | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Rights to Purchase Preferred Stock |
| Trading Symbol | IESC |
| Security Exchange Name | NASDAQ |
