Summary of Significant Accounting Policies and Select Balance Sheet Information - Schedule of Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Accrued Liabilities Current [Abstract]
Accrued professional fees	$ 311	$ 501
Accrued clinical study expense	2,839	411
Accrued purchases	533	596
Customer claim	1,000
Construction in progress	1,199
Deferred rent	121	18
Other	262	247
Total	$ 6,265	$ 1,773