Income Taxes - Summary of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Sep. 30, 2015
Deferred tax assets:
Net non-U.S. operating loss carryforwards	$ 777	$ 595
Employee benefits	3,366	3,340
Inventory reserves	1,032	865
Allowance for doubtful accounts	234	377
Foreign tax credits to undistributed earnings	870	0
Intangibles	4,364	1,936
Foreign tax credits	575	517
Other	2,307	1,007
Total deferred tax assets	13,525	8,637
Deferred tax liabilities:
Depreciation	(10,777)	(9,022)
Unremitted foreign earnings	(65)	(65)
Prepaid expenses	(566)	(432)
Other	(647)	(87)
Total deferred tax liabilities	(12,055)	(9,606)
Net deferred tax assets (liabilities)	1,470	(969)
Valuation allowance	(4,399)	(1,095)
Net deferred tax liabilities	$ (2,929)	$ (2,064)