COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
Jul. 01, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Anticipated costs	$ 125.2	$ 124.9
Term of purchase commitments	1 year
Site Restoration Obligations \| Other noncurrent liabilities
Loss Contingencies [Line Items]
Site restoration obligation, non-current	$ 36.6	36.3
Site Restoration Obligations \| Accrued expenses.
Loss Contingencies [Line Items]
Site restoration obligation, current	$ 4.9	4.0
Summit Materials, LLC
Loss Contingencies [Line Items]
Term of purchase commitments	1 year
Summit Materials, LLC \| Site Restoration Obligations
Loss Contingencies [Line Items]
Anticipated costs	$ 125.2	124.9
Summit Materials, LLC \| Site Restoration Obligations \| Other noncurrent liabilities
Loss Contingencies [Line Items]
Site restoration obligation, non-current	36.6	36.3
Summit Materials, LLC \| Site Restoration Obligations \| Accrued expenses.
Loss Contingencies [Line Items]
Site restoration obligation, current	$ 4.9	$ 4.0

Total undiscounted anticipated costs for asset retirement obligations.

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- Definition

Term of purchase commitment, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 410
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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-Publisher FASB
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+ References

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
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-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org//1943274/2147482425/460-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 450
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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