Goodwill and Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 41,625	$ 40,969
Accumulated Amortization	11,035	9,556
Intangible assets, net	30,590	31,413
Trademarks And Trade Names - Finite [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	5,084	4,643
Accumulated Amortization	831	440
Intangible assets, net	$ 4,253	$ 4,203
Trademarks And Trade Names - Finite [Member] | Minimum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	5 years	5 years
Trademarks And Trade Names - Finite [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	20 years	20 years
Technical Library [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	20 years	20 years
Gross Carrying Amount	$ 400	$ 400
Accumulated Amortization	101	81
Intangible assets, net	299	319
Customer Relationships [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	33,539	31,115
Accumulated Amortization	7,870	4,741
Intangible assets, net	$ 25,669	$ 26,374
Customer Relationships [Member] | Minimum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	6 years	6 years
Customer Relationships [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	15 years	15 years
NoncompeteAgreementsMember
IntangibleAssets [Line Items]
Estimated Useful Lives	5 years	5 years
Gross Carrying Amount	$ 40	$ 0
Accumulated Amortization	1	0
Intangible assets, net	$ 39	$ 0
Order Backlog [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	1 year	1 year
Gross Carrying Amount	$ 378	$ 2,412
Accumulated Amortization	176	2,130
Intangible assets, net	$ 202	$ 282
Construction Contract Value [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	1 year	1 year
Gross Carrying Amount	$ 2,184	$ 2,399
Accumulated Amortization	2,056	2,164
Intangible assets, net	$ 128	$ 235