Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Apr. 01, 2017	Dec. 31, 2016
Inventories
Aggregate stockpiles	$ 114,226	$ 103,073
Finished goods	47,968	35,071
Work in process	5,409	6,440
Raw materials	19,395	13,095
Total	186,998	157,679
Summit Materials, LLC
Inventories
Aggregate stockpiles	114,226	103,073
Finished goods	47,968	35,071
Work in process	5,409	6,440
Raw materials	19,395	13,095
Total	$ 186,998	$ 157,679

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 of unprocessed items to be consumed in the manufacturing or production process.

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Carrying amount, net of reserves and adjustments, as of the balance sheet date of merchandise or goods which are partially completed. This inventory is generally comprised of raw materials, labor and factory overhead costs, which require further materials, labor and overhead to be converted into finished goods, and which generally require the use of estimates to determine percentage complete and pricing.

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