Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 4,385	$ 4,453
Work in process	5,926	5,168
Finished goods	1,830	1,746
Parts and supplies	11,740	9,599
Total inventories	$ 23,881	$ 20,966

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of other inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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