Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Schedule Of Income Taxes [Line Items]
Deferred tax asset	$ 37,945,000	$ 36,509,000
Research and development tax credit carryforwards	418,000
Net operating loss and other carryforwards	35,529,000	34,563,000
Deferred tax liability, unremitted earnings of foreign subsidiaries	0
Unremitted foreign earnings	$ 925,000
Goodwill for tax purposes amortization period	15 years
Deferred tax liability	$ 4,426,000	4,564,000
Accruals of interest and penalties	0
Recognized interest or penalties	0	0
Additional Paid-in Capital
Schedule Of Income Taxes [Line Items]
Net operating loss and other carryforwards	$ 1,100,000
Minimum | Research Tax Credit Carryforward
Schedule Of Income Taxes [Line Items]
Research and development tax credit carryforwards expire date	2019
Maximum | Research Tax Credit Carryforward
Schedule Of Income Taxes [Line Items]
Research and development tax credit carryforwards expire date	2020
Federal Tax
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards	$ 97,000,000
Federal Tax | Minimum
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards for federal tax purposes	2019
Federal Tax | Maximum
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards for federal tax purposes	2037
State tax
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards	$ 44,000,000
State tax | Minimum
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards for federal tax purposes	2017
State tax | Maximum
Schedule Of Income Taxes [Line Items]
Operating loss carryforwards for federal tax purposes	2036
Prepaid Expenses and Other Current Assets
Schedule Of Income Taxes [Line Items]
Deferred tax asset	$ 97,000	$ 66,000