Goodwil and Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2016
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 39,800	$ 35,871
Accumulated Amortization	8,300	4,148
Intangible assets, net	31,500	31,723
Trademarks And Trade Names [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	4,374	3,845
Accumulated Amortization	350	139
Intangible assets, net	$ 4,024	$ 3,706
Trademarks And Trade Names [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	20 years	20 years
Trademarks And Trade Names [Member] | Minimum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	5 years	5 years
Technical Library [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 400	$ 400
Accumulated Amortization	76	61
Intangible assets, net	$ 324	$ 339
Technical Library [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	20 years	20 years
Customer Relationships [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 30,284	$ 27,414
Accumulated Amortization	4,015	2,003
Intangible assets, net	$ 26,269	$ 25,411
Customer Relationships [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	15 years	15 years
Customer Relationships [Member] | Minimum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	6 years	6 years
Developed Technology [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 400	$ 400
Accumulated Amortization	400	358
Intangible assets, net	$ 0	$ 42
Developed Technology [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	4 years	4 years
Order Backlog [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 2,151	$ 1,621
Accumulated Amortization	1,614	545
Intangible assets, net	$ 537	$ 1,076
Order Backlog [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	1 year	1 year
Construction Contract Value [Member]
IntangibleAssets [Line Items]
Gross Carrying Amount	$ 2,191	$ 2,191
Accumulated Amortization	1,845	1,042
Intangible assets, net	$ 346	$ 1,149
Construction Contract Value [Member] | Maximum [Member]
IntangibleAssets [Line Items]
Estimated Useful Lives	1 year	1 year