Summary of Significant Accounting Policies and Select Balance Sheet Information - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Intangible Assets [Line Items]
Definite-lived intangible assets, Accumulated Amortization	$ (13,457)	$ (10,838)
Intangible assets, Gross Carrying Amount	31,140	31,400
Intangible assets, Net	$ 17,683	$ 20,562
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	$ 18,086	$ 18,293
Definite-lived intangible assets, Accumulated Amortization	(9,377)	(7,834)
Definite-lived intangible assets, Net	$ 8,709	$ 10,459
Developed Technology [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	11 years 6 months	11 years 8 months 12 days
Definite-lived intangible assets, Gross Carrying Amount	$ 9,656	$ 9,297
Definite-lived intangible assets, Accumulated Amortization	(2,361)	(1,478)
Definite-lived intangible assets, Net	$ 7,295	$ 7,819
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	(150)	(103)
Definite-lived intangible assets, Net	$ 80	$ 127
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	(1,569)	(1,423)
Definite-lived intangible assets, Net	752	898
Definite-Lived Intangible Assets [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Gross Carrying Amount	30,293	30,141
Definite-lived intangible assets, Accumulated Amortization	(13,457)	(10,838)
Definite-lived intangible assets, Net	16,836	19,303
In-Process Research and Development [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net	267	679
Trademarks and Trade Names [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net	$ 580	$ 580