DEBT - Other (Details) - CAD ($)	Jan. 15, 2015	Jul. 01, 2023	Dec. 31, 2022
Canadian Subsidiary Credit Agreement, Operating Activities
Debt Instrument [Line Items]
Revolving credit commitment	$ 6,000,000
Canadian Subsidiary Credit Agreement, Capital Equipment
Debt Instrument [Line Items]
Revolving credit commitment	500,000
Canadian Subsidiary Credit Agreement, Guarantees
Debt Instrument [Line Items]
Revolving credit commitment	1,500,000
Canadian Subsidiary Credit Agreement, Foreign Exchange Facility
Debt Instrument [Line Items]
Revolving credit commitment	$ 10,000,000
Canadian Subsidiary Credit Agreement
Debt Instrument [Line Items]
Amount outstanding		$ 0	$ 0
Prime rate | Canadian Subsidiary Credit Agreement, Operating Activities
Debt Instrument [Line Items]
Basis spread on variable rate	0.20%
Prime rate | Canadian Subsidiary Credit Agreement, Capital Equipment
Debt Instrument [Line Items]
Basis spread on variable rate	0.20%
Summit Materials, LLC | Canadian Subsidiary Credit Agreement, Operating Activities
Debt Instrument [Line Items]
Revolving credit commitment	$ 6,000,000
Summit Materials, LLC | Canadian Subsidiary Credit Agreement, Capital Equipment
Debt Instrument [Line Items]
Revolving credit commitment	500,000
Summit Materials, LLC | Canadian Subsidiary Credit Agreement, Guarantees
Debt Instrument [Line Items]
Revolving credit commitment	$ 1,500,000
Summit Materials, LLC | Canadian Subsidiary Credit Agreement
Debt Instrument [Line Items]
Amount outstanding		$ 0	$ 0
Summit Materials, LLC | Prime rate | Canadian Subsidiary Credit Agreement, Operating Activities
Debt Instrument [Line Items]
Basis spread on variable rate	0.20%
Summit Materials, LLC | Prime rate | Canadian Subsidiary Credit Agreement, Capital Equipment
Debt Instrument [Line Items]
Basis spread on variable rate	0.20%