ACQUISITIONS, DISPOSTIONS, GOODWILL AND INTANGIBLES - Summary of Goodwill by Reportable Segments (Details) $ in Thousands	6 Months Ended
Jul. 01, 2023 USD ($)
Goodwill [Roll Forward]
Balance—December 31, 2022	$ 1,132,546
Acquisitions	94,564
Foreign currency translation adjustments	1,358
Balance—July 1, 2023	1,228,468
West
Goodwill [Roll Forward]
Balance—December 31, 2022	566,389
Acquisitions	94,564
Foreign currency translation adjustments	1,358
Balance—July 1, 2023	662,311
East
Goodwill [Roll Forward]
Balance—December 31, 2022	361,501
Acquisitions	0
Foreign currency translation adjustments	0
Balance—July 1, 2023	361,501
Cement
Goodwill [Roll Forward]
Balance—December 31, 2022	204,656
Acquisitions	0
Foreign currency translation adjustments	0
Balance—July 1, 2023	204,656
Summit Materials, LLC
Goodwill [Roll Forward]
Balance—December 31, 2022	1,133,546
Acquisitions	94,564
Foreign currency translation adjustments	1,358
Balance—July 1, 2023	1,229,468
Summit Materials, LLC \| West
Goodwill [Roll Forward]
Balance—December 31, 2022	567,389
Acquisitions	94,564
Foreign currency translation adjustments	1,358
Balance—July 1, 2023	663,311
Summit Materials, LLC \| East
Goodwill [Roll Forward]
Balance—December 31, 2022	361,501
Acquisitions	0
Foreign currency translation adjustments	0
Balance—July 1, 2023	361,501
Summit Materials, LLC \| Cement
Goodwill [Roll Forward]
Balance—December 31, 2022	204,656
Acquisitions	0
Foreign currency translation adjustments	0
Balance—July 1, 2023	$ 204,656

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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