Per Share Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Undistributed Earnings (Loss) Available to Common Shareholders, Basic	$ 16,630	$ 6,926	$ 58,748	$ 15,043
Noncontrolling Interest, Change in Redemption Value	(5,916)	(2,534)	(11,742)	(3,464)
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0	(5)	(9)	(10)
Net income (loss) attributable to IES Holdings, Inc.	$ 22,546	$ 9,465	$ 70,499	$ 18,517
Weighted Average Number of Shares Outstanding, Basic	20,181,793	20,718,195	20,198,474	20,730,900
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	223,909	221,242	205,861	544,926
Weighted Average Number of Shares Outstanding, Diluted	20,405,702	20,939,437	20,404,335	21,275,826
Earnings Per Share, Basic	$ 0.82	$ 0.33	$ 2.91	$ 0.73
Earnings Per Share, Diluted	$ 0.81	$ 0.33	$ 2.88	$ 0.71