DEBT - Schedule of Contractual Payments of Long-Term Debt (Details) $ in Thousands	Mar. 28, 2020 USD ($)
Debt Instrument [Line Items]
2020 (nine months)	$ 6,354
2021	6,353
2022	6,354
2023	656,354
2024	597,253
2025	300,000
Thereafter	300,000
Total	1,872,668
Less: Original issue net discount	(1,866)
Less: Capitalized loan costs	(12,571)
Total debt	1,858,231
Summit Materials, LLC
Debt Instrument [Line Items]
2020 (nine months)	6,354
2021	6,353
2022	6,354
2023	656,354
2024	597,253
2025	300,000
Thereafter	300,000
Total	1,872,668
Less: Original issue net discount	(1,866)
Less: Capitalized loan costs	(12,571)
Total debt	$ 1,858,231

Long-Term Debt, Maturities, Repayments Of Principal After Year Six

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Long-Term Debt, Maturities, Repayments Of Principal In Year Six

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Carrying amount of long-term debt, net of unamortized discount or premium and debt issuance costs, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount.

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The carrying amount of deferred costs.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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