ACQUISITIONS, DISPOSTIONS, GOODWILL AND INTANGIBLES - Intangible Assets By Type (Details) - USD ($) $ in Thousands	Apr. 02, 2022	Jan. 01, 2022
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (16,218)	$ (15,269)
Operating permits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	33,671	33,671
Accumulated Amortization	(2,987)	(2,467)
Net Carrying Amount	30,684	31,204
Mineral leases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	15,463	19,927
Accumulated Amortization	(6,105)	(8,922)
Net Carrying Amount	9,358	11,005
Reserve rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	25,586	25,586
Accumulated Amortization	(3,535)	(3,329)
Net Carrying Amount	22,051	22,257
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,286	5,481
Accumulated Amortization	(364)	(551)
Net Carrying Amount	4,922	4,930
Excluding Intangible Assets Held For Sale
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	80,006	84,665
Accumulated Amortization	(12,991)	(15,269)
Net Carrying Amount	67,015	69,396
Summit Materials, LLC
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	(16,218)	(15,269)
Summit Materials, LLC | Operating permits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	33,671	33,671
Accumulated Amortization	(2,987)	(2,467)
Net Carrying Amount	30,684	31,204
Summit Materials, LLC | Mineral leases
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	15,463	19,927
Accumulated Amortization	(6,105)	(8,922)
Net Carrying Amount	9,358	11,005
Summit Materials, LLC | Reserve rights
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	25,586	25,586
Accumulated Amortization	(3,535)	(3,329)
Net Carrying Amount	22,051	22,257
Summit Materials, LLC | Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,286	5,481
Accumulated Amortization	(364)	(551)
Net Carrying Amount	4,922	4,930
Summit Materials, LLC | Excluding Intangible Assets Held For Sale
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	80,006	84,665
Accumulated Amortization	(12,991)	(15,269)
Net Carrying Amount	$ 67,015	$ 69,396