Details of Selected Balance Sheet Accounts - Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Details of Selected Balance Sheet Accounts [Abstract]
Finished goods and purchased products	$ 90,623	$ 88,634
Work in process	30,248	27,063
Raw materials	93,968	95,410
Total inventories	214,839	211,107
Allowance for excess or obsolete inventory	(39,790)	(40,731)
Inventories, net	$ 175,049	$ 170,376

Details of Selected Balance Sheet Accounts [Abstract]

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

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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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 of valuation reserve for inventory.

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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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