Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Revenues	$ 480,509	$ 314,838
Cost of services	400,782	256,159
Gross profit	79,727	58,679
Selling, general and administrative expenses	59,402	42,786
Contingent consideration	69	0
Loss (gain) on sale of assets	(5)	(10)
Operating income (loss)	20,261	15,903
Interest expense	436	172
Other (income) expense, net	765	(118)
Income (loss) from operations before income taxes	19,060	15,849
Provision for (benefit from) income taxes	3,981	3,639
Net income (loss)	15,079	12,210
Net income attributable to noncontrolling interest	(615)	(112)
Comprehensive income attributable to IES Holdings, Inc.	$ 14,464	$ 12,098
Earnings Per Share, Basic	$ 0.70	$ 0.58
Earnings Per Share, Diluted	$ 0.69	$ 0.58
Weighted Average Number of Shares Outstanding, Basic	20,702,844	20,734,516
Weighted Average Number of Shares Outstanding, Diluted	20,958,887	21,061,355