LEASES - Operating and Finance Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2023	Jul. 02, 2022	Jul. 01, 2023	Jul. 02, 2022	Dec. 31, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 2,697	$ 2,271	$ 5,338	$ 4,783
Variable lease cost	34	42	64	155
Short-term lease cost	10,184	10,933	17,454	19,181
Financing lease cost:
Amortization of right-of-use assets	714	1,377	1,532	3,363
Interest on lease liabilities	133	271	281	640
Total lease cost	13,762	14,894	24,669	28,122
Operating leases:
Operating lease right-of-use assets	36,013		36,013		$ 37,889
Current operating lease liabilities	7,707		7,707		7,296
Noncurrent operating lease liabilities	33,563		33,563		35,737
Total operating lease liabilities	41,270		41,270		43,033
Finance leases:
Property and equipment, gross	21,515		21,515		32,119
Less accumulated depreciation	$ (10,101)		$ (10,101)		$ (14,992)
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant and equipment, net		Property, plant and equipment, net		Property, plant and equipment, net
Property and equipment, net	$ 11,414		$ 11,414		$ 17,127
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued expenses		Accrued expenses		Accrued expenses
Current finance lease liabilities	$ 3,499		$ 3,499		$ 6,959
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other noncurrent liabilities		Other noncurrent liabilities		Other noncurrent liabilities
Long-term finance lease liabilities	$ 5,820		$ 5,820		$ 7,167
Total finance lease liabilities	$ 9,319		$ 9,319		$ 14,126
Weighted average remaining lease term (years):
Operating leases	8 years 9 months 18 days		8 years 9 months 18 days		9 years 1 month 6 days
Finance lease	3 years 6 months		3 years 6 months		2 years 9 months 18 days
Weighted average discount rate:
Operating leases	4.80%		4.80%		4.70%
Finance leases	5.70%		5.70%		5.30%
Operating Leases
2023 (six months)	$ 4,831		$ 4,831
2024	8,762		8,762
2025	6,787		6,787
2026	5,242		5,242
2027	4,233		4,233
2028	3,432		3,432
Thereafter	17,664		17,664
Total lease payments	50,951		50,951
Less imputed interest	(9,681)		(9,681)
Present value of lease payments	41,270		41,270		$ 43,033
Finance Leases
2023 (six months)	2,142		2,142
2024	3,052		3,052
2025	2,435		2,435
2026	990		990
2027	760		760
2028	513		513
Thereafter	570		570
Total lease payments	10,462		10,462
Less imputed interest	(1,143)		(1,143)
Present value of lease payments	9,319		9,319		14,126
Summit Materials, LLC
Lease, Cost [Abstract]
Operating lease cost	2,697	2,271	5,338	4,783
Variable lease cost	34	42	64	155
Short-term lease cost	10,184	10,933	17,454	19,181
Financing lease cost:
Amortization of right-of-use assets	714	1,377	1,532	3,363
Interest on lease liabilities	133	271	281	640
Total lease cost	13,762	$ 14,894	24,669	$ 28,122
Operating leases:
Operating lease right-of-use assets	36,013		36,013		37,889
Current operating lease liabilities	7,707		7,707		7,296
Noncurrent operating lease liabilities	33,563		33,563		35,737
Total operating lease liabilities	41,270		41,270		43,033
Finance leases:
Property and equipment, gross	21,515		21,515		32,119
Less accumulated depreciation	$ (10,101)		$ (10,101)		$ (14,992)
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, plant and equipment, net		Property, plant and equipment, net		Property, plant and equipment, net
Property and equipment, net	$ 11,414		$ 11,414		$ 17,127
Current finance lease liabilities	3,499		3,499		6,959
Long-term finance lease liabilities	5,820		5,820		7,167
Total finance lease liabilities	$ 9,319		$ 9,319		$ 14,126
Weighted average remaining lease term (years):
Operating leases	8 years 9 months 18 days		8 years 9 months 18 days		9 years 1 month 6 days
Finance lease	3 years 6 months		3 years 6 months		2 years 9 months 18 days
Weighted average discount rate:
Operating leases	4.80%		4.80%		4.70%
Finance leases	5.70%		5.70%		5.30%
Operating Leases
2023 (six months)	$ 4,831		$ 4,831
2024	8,762		8,762
2025	6,787		6,787
2026	5,242		5,242
2027	4,233		4,233
2028	3,432		3,432
Thereafter	17,664		17,664
Total lease payments	50,951		50,951
Less imputed interest	(9,681)		(9,681)
Present value of lease payments	41,270		41,270		$ 43,033
Finance Leases
2023 (six months)	2,142		2,142
2024	3,052		3,052
2025	2,435		2,435
2026	990		990
2027	760		760
2028	513		513
Thereafter	570		570
Total lease payments	10,462		10,462
Less imputed interest	(1,143)		(1,143)
Present value of lease payments	$ 9,319		$ 9,319		$ 14,126