Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Inventory [Line Items]
Raw materials and components	$ 102,959	$ 83,834
Finished goods	94,486	54,000
Work in progress	27,783	29,123
Aftermarket parts	6,213	6,448
Used trailers	2,681	7,330
Total, Inventories	$ 234,122	$ 180,735

Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

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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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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date for elements of machinery or equipment held for the purpose of replacing similar parts in the course of repair or maintenance.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of unprocessed items to be consumed in the manufacturing or production process.

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

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