Goodwill and Intangible Assets Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Goodwill [Line Items]
Goodwill, beginning		$ 53,763	$ 50,622
Goodwill, Acquired During Period		38,632	10,117
Goodwill, Purchase Accounting Adjustments			(6,976)
Impairment expense	$ 0		(6,976)	$ 0
Goodwill, ending	92,395	92,395	53,763	50,622
Communications [Member]
Goodwill [Line Items]
Goodwill, beginning		2,816	2,816
Impairment expense			0
Goodwill, ending	2,816	2,816	2,816	2,816
Residential [Member]
Goodwill [Line Items]
Goodwill, beginning		16,219	10,018
Goodwill, Acquired During Period		35,151	6,201
Goodwill, Purchase Accounting Adjustments			0
Impairment expense			0
Goodwill, ending	51,370	51,370	16,219	10,018
Infrastructure Solutions [Member]
Goodwill [Line Items]
Goodwill, beginning		34,728	30,812
Goodwill, Acquired During Period		3,481	3,916
Impairment expense			0
Goodwill, ending	38,209	38,209	34,728	30,812
Commercial and Industrial [Member]
Goodwill [Line Items]
Goodwill, beginning		0	6,976
Goodwill, Purchase Accounting Adjustments			(6,976)
Impairment expense		0	(6,976)
Goodwill, ending	$ 0	$ 0	$ 0	$ 6,976