Inventories - Schedule of Inventories (Details) - USD ($) $ in Thousands	Aug. 31, 2021	Aug. 31, 2020
Inventory Net [Abstract]
Processed and unprocessed scrap metal	$ 164,960	$ 63,058
Semi-finished goods	7,671	6,909
Finished goods	39,368	44,476
Supplies	44,428	42,826
Inventories	$ 256,427	$ 157,269

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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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of products used directly or indirectly in the manufacturing or production process, which may or may not become part of the final product. May also include items used in the storage, presentation or transportation of physical goods.

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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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