REVENUE RECOGNITION - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	9 Months Ended
Oct. 02, 2021	Jan. 02, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 268,188	$ 191,871
Construction contract receivables	53,647	47,179
Retention receivables	14,894	18,824
Receivables from related parties	877	1,339
Accounts receivable	337,606	259,213
Less: Allowance for doubtful accounts	(4,255)	(4,517)
Accounts receivable, net	$ 333,351	254,696
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
General collection and billing period for retention receivables	1 year
Summit Materials, LLC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 268,188	191,871
Construction contract receivables	53,647	47,179
Retention receivables	14,894	18,824
Receivables from related parties	877	1,339
Accounts receivable	337,606	259,213
Less: Allowance for doubtful accounts	(4,255)	(4,517)
Accounts receivable, net	$ 333,351	$ 254,696
Summit Materials, LLC \| Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
General collection and billing period for retention receivables	1 year

The general collection and billing period for retention receivables.

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Amounts earned by entity but held by customers until projects have been fully completed or near completion and are expected to be billed and collected within one year of the balance sheet date (or the normal operating cycle, whichever is longer).

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Trade receivable amounts due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer) for goods or services.

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Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

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For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

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Amount of allowance for credit loss on accounts receivable, classified as current.

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Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

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