Income Tax Expense - Additional information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Income Tax Expense
Operating loss carry forwards, valuation allowance	$ 500	$ 500
Net operating loss carry forward - foreign	3,396	4,279
Deferred tax assets, operating loss carry forwards, not subject to expiration	10,400
Deferred tax assets, operating loss carry forwards, subject to expiration	1,700
Tax credit carryforward, amount	200
Deferred tax assets, operating loss carry forwards, state and local	600
Deferred tax assets, tax credit carry forwards, research	1,700
State research and other credit carry forwards with expiration date	900
State research and other credit carry forwards without expiration date	800
Deferred tax assets, valuation allowance	1,208	2,011
Reduction in valuation allowance for excess foreign tax credits	800	100
Unrecognized tax benefits	0
Foreign Valuation Allowance
Income Tax Expense
Operating loss carry forwards, valuation allowance	700	900
State and Local Jurisdiction
Income Tax Expense
Operating loss carry forwards, valuation allowance	600	$ 600
Net operating loss carry forward - foreign	$ 12,100