Intangible Assets - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Intangible Assets [Line Items]
Definite-lived intangible assets, Accumulated Amortization	$ (9,814)	$ (8,604)
Intangible assets, Gross Carrying Amount	30,932	31,129
Intangible assets, Net	$ 21,118	$ 22,525
Customer Lists and Relationships [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	8 years 10 months 24 days	8 years 10 months 24 days
Definite-lived intangible assets, Gross Carrying Amount	$ 17,187	$ 17,692
Definite-lived intangible assets, Accumulated Amortization	(6,842)	(6,123)
Definite-lived intangible assets, Net	$ 10,345	$ 11,569
Core Technology [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	8 years	8 years
Definite-lived intangible assets, Gross Carrying Amount	$ 530	$ 530
Definite-lived intangible assets, Accumulated Amortization	$ (530)	$ (530)
Developed Technology [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	11 years 9 months 18 days	11 years 9 months 18 days
Definite-lived intangible assets, Gross Carrying Amount	$ 9,077	$ 8,724
Definite-lived intangible assets, Accumulated Amortization	(1,012)	(618)
Definite-lived intangible assets, Net	$ 8,065	$ 8,106
Non-compete [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	5 years	5 years
Definite-lived intangible assets, Gross Carrying Amount	$ 230	$ 230
Definite-lived intangible assets, Accumulated Amortization	(81)	(58)
Definite-lived intangible assets, Net	$ 149	$ 172
Patents and Other [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	16 years 6 months	16 years 6 months
Definite-lived intangible assets, Gross Carrying Amount	$ 2,321	$ 2,321
Definite-lived intangible assets, Accumulated Amortization	(1,349)	(1,275)
Definite-lived intangible assets, Net	972	1,046
Definite-Lived Intangible Assets [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Gross Carrying Amount	29,345	29,497
Definite-lived intangible assets, Accumulated Amortization	(9,814)	(8,604)
Definite-lived intangible assets, Net	19,531	20,893
In-Process Research and Development [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net	945	987
Trademarks and Trade Names [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net	$ 642	$ 645