Summary of Significant Accounting Policies and Select Balance Sheet Information - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Intangible Assets [Line Items]
Definite-lived intangible assets, Accumulated Amortization	$ (10,838)	$ (8,604)
Intangible assets, Gross Carrying Amount	31,400	31,129
Intangible assets, Net	$ 20,562	$ 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	$ 18,293	$ 17,692
Definite-lived intangible assets, Accumulated Amortization	(7,834)	(6,123)
Definite-lived intangible assets, Net	$ 10,459	$ 11,569
Core Technology [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)		8 years
Definite-lived intangible assets, Gross Carrying Amount		$ 530
Definite-lived intangible assets, Accumulated Amortization		$ (530)
Developed Technology [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Weighted Average Original Life (Years)	11 years 8 months 12 days	11 years 9 months 18 days
Definite-lived intangible assets, Gross Carrying Amount	$ 9,297	$ 8,724
Definite-lived intangible assets, Accumulated Amortization	(1,478)	(618)
Definite-lived intangible assets, Net	$ 7,819	$ 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	(103)	(58)
Definite-lived intangible assets, Net	$ 127	$ 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	(1,423)	(1,275)
Definite-lived intangible assets, Net	898	1,046
Definite-Lived Intangible Assets [Member]
Intangible Assets [Line Items]
Definite-lived intangible assets, Gross Carrying Amount	30,141	29,497
Definite-lived intangible assets, Accumulated Amortization	(10,838)	(8,604)
Definite-lived intangible assets, Net	19,303	20,893
In-Process Research and Development [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net	679	987
Trademarks and Trade Names [Member]
Intangible Assets [Line Items]
Indefinite-lived intangible assets, Net	$ 580	$ 645