Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw material	$ 51,860		$ 42,661
Work-in-process	7,861		10,598
Finished goods	37,765		33,113
Total inventories	$ 97,486	$ 81,637	$ 86,372

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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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