Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment
Stockholders' Equity Attributable to Parent at Sep. 30, 2020	$ 283,313		$ 220	$ (24,499)	$ 200,587	$ 107,005
Shares, Issued at Sep. 30, 2020			22,049,529	1,287,134
Issuances under compensation plans				$ (741)	(741)
Issuances under compensation plans, shares				38,467
Acquisition of treasury stock	(695)			$ (1,226)	531
Acquisition of treasury stock, shares				(30,878)
Non-cash compensation	842				842
Noncontrolling Interest, Change in Redemption Value	(118)					(118)
Net income (loss) attributable to IES Holdings, Inc.	12,098					12,098
Stockholders' Equity Attributable to Parent at Dec. 31, 2020	295,462	$ (214)	$ 220	$ (24,984)	201,219	119,007	$ (214)
Shares, Issued at Dec. 31, 2020			22,049,529	1,279,545
Stockholders' Equity Attributable to Parent at Sep. 30, 2021	345,953		$ 220	$ (29,300)	201,899	173,134
Shares, Issued at Sep. 30, 2021			22,049,529	1,316,998
Issuances under compensation plans				$ (3,637)	(3,637)
Issuances under compensation plans, shares				157,167
Acquisition of treasury stock	(4,797)			$ (4,797)	0
Acquisition of treasury stock, shares				(101,613)
Non-cash compensation	900				900
Noncontrolling Interest, Change in Redemption Value	(60)					(60)
Net income (loss) attributable to IES Holdings, Inc.	14,464					14,464
Stockholders' Equity Attributable to Parent at Dec. 31, 2021	$ 356,460		$ 220	$ (30,460)	$ 199,162	$ 187,538
Shares, Issued at Dec. 31, 2021			22,049,529	1,261,444