Income Taxes - Reconciliation of Income Tax Expense (Benefit) Computed at Country Specific Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income tax expense (benefit) at statutory rate	$ (1,800)	$ (1,036)
State income tax expense (benefit)	(192)	(130)
Foreign tax activity	41	9
R&D tax credit expiration	0	0
Permanent differences, net	469	274
Adjustment of temporary differences to income tax returns	0	0
Change in valuation allowance	1,403	1,152
Income tax expense	$ (79)	$ 269