Goodwill and Intangible Assets Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 58,026	$ 39,662
Finite-Lived Intangible Assets, Accumulated Amortization	(18,669)	(13,039)
Intangible Assets, Net (Excluding Goodwill)	39,357	26,623
Amortization of Intangible Assets	6,424	3,950	$ 4,101
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	6,217
Finite-Lived Intangible Assets, Amortization Expense, Year Two	4,634
Finite-Lived Intangible Assets, Amortization Expense, Year Three	4,241
Finite-Lived Intangible Assets, Amortization Expense, Year Four	3,898
Finite-Lived Intangible Assets, Amortization Expense, Year Five	3,571
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	16,796
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	7,754	5,084
Finite-Lived Intangible Assets, Accumulated Amortization	(1,741)	(1,267)
Intangible Assets, Net (Excluding Goodwill)	$ 6,013	$ 3,817
Trademarks and Trade Names [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Trademarks and Trade Names [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years	20 years
Technical Library
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 400	$ 400
Finite-Lived Intangible Assets, Accumulated Amortization	(141)	(121)
Intangible Assets, Net (Excluding Goodwill)	$ 259	$ 279
Technical Library | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years	20 years
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 46,449	$ 33,539
Finite-Lived Intangible Assets, Accumulated Amortization	(14,900)	(11,051)
Intangible Assets, Net (Excluding Goodwill)	$ 31,549	$ 22,488
Customer Relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	6 years	6 years
Customer Relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years	15 years
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 40	$ 40
Finite-Lived Intangible Assets, Accumulated Amortization	(17)	(9)
Intangible Assets, Net (Excluding Goodwill)	$ 23	$ 31
Noncompete Agreements [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years	5 years
Construction Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 3,383	$ 599
Finite-Lived Intangible Assets, Accumulated Amortization	(1,870)	(591)
Intangible Assets, Net (Excluding Goodwill)	$ 1,513	$ 8
Construction Contracts [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year	1 year