Income Tax Expense - Additional information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Income Tax Expense
Operating loss carry forwards, valuation allowance	$ 500	$ 500
Net operating loss carry forward - foreign	3,714	3,396
Deferred tax assets, operating loss carry forwards, not subject to expiration	11,100
Deferred tax assets, operating loss carry forwards, subject to expiration	2,100
Deferred tax assets, operating loss carry forwards, state and local	600
Deferred tax assets, tax credit carry forwards, research	2,200
State research and other credit carry forwards with expiration date	800
State research and other credit carry forwards without expiration date	1,400
Deferred tax assets, valuation allowance	1,772	1,208
Reduction in valuation allowance for excess foreign tax credits	600	800
Unrecognized tax benefits	0
Foreign Valuation Allowance
Income Tax Expense
Operating loss carry forwards, valuation allowance	1,300	$ 700
State and Local Jurisdiction
Income Tax Expense
Operating loss carry forwards, valuation allowance	600
Net operating loss carry forward - foreign	$ 13,200