Income Taxes - Deferred tax assets (liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Deferred tax assets:
Pension	$ 1,378	$ 1,390
Intangibles	81	104
Other reserves and accruals	291	451
Inventory reserves and other	619	502
State credits, net of federal benefit	380	380
Federal and state net operating loss carryforwards	928	626
Foreign net operating loss carryforwards	1,393	1,489
Foreign exchange on intercompany loan	7	7
Depreciation and amortization	(232)	(396)
Gross deferred tax assets	4,845	4,553
Less: valuation allowance	(2,899)	(2,658)
Realizable deferred tax asset	1,946	1,895
Gross deferred tax liabilities	0	0
Net deferred tax assets	$ 1,946	$ 1,895