ACQUISITIONS, DISPOSTIONS, GOODWILL AND INTANGIBLES - Acquisitions by Region (Details) - acquisition	3 Months Ended	6 Months Ended
	Apr. 01, 2023	Jul. 02, 2022
West
Business Acquisition [Line Items]
Number of businesses acquired	1	0
West | Summit Materials, LLC
Business Acquisition [Line Items]
Number of businesses acquired	1	0
East
Business Acquisition [Line Items]
Number of businesses acquired	0	2
East | Summit Materials, LLC
Business Acquisition [Line Items]
Number of businesses acquired	0	2