Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Oct. 01, 2022	Jan. 01, 2022
Accumulated depreciation, depletion and amortization	$ 1,241,028	$ 1,266,513
Accumulated amortization	14,642	15,269
Valuation allowance	1,113	1,675
Summit Materials, LLC
Accumulated depreciation, depletion and amortization	1,241,028	1,266,513
Accumulated amortization	$ 14,642	$ 15,269
Common Class A
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	116,386,969	118,705,108
Common stock, shares outstanding (in shares)	116,386,969	118,705,108
Common Class B
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	99	99
Common stock, shares outstanding (in shares)		99