Goodwill - Summary of Goodwill by Reportable Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Jan. 01, 2022
Goodwill [Roll Forward]
Beginning balance	$ 1,163,750	$ 1,201,291
Dispositions	(27,084)	(38,063)
Foreign currency translation adjustments	(4,120)	522
Ending balance	1,132,546	1,163,750
Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	1,164,750	1,202,291
Dispositions	(27,084)	(38,063)
Foreign currency translation adjustments	(4,120)	522
Ending balance	1,133,546	1,164,750
West
Goodwill [Roll Forward]
Beginning balance	570,509	586,209
Dispositions	0	(16,222)
Foreign currency translation adjustments	(4,120)	522
Ending balance	566,389	570,509
West \| Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	571,509	587,209
Dispositions	0	(16,222)
Foreign currency translation adjustments	(4,120)	522
Ending balance	567,389	571,509
East
Goodwill [Roll Forward]
Beginning balance	388,585	410,426
Dispositions	(27,084)	(21,841)
Foreign currency translation adjustments	0	0
Ending balance	361,501	388,585
East \| Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	388,585	410,426
Dispositions	(27,084)	(21,841)
Foreign currency translation adjustments	0	0
Ending balance	361,501	388,585
Cement
Goodwill [Roll Forward]
Beginning balance	204,656	204,656
Dispositions	0	0
Foreign currency translation adjustments	0	0
Ending balance	204,656	204,656
Cement \| Summit Materials, LLC
Goodwill [Roll Forward]
Beginning balance	204,656	204,656
Dispositions	0	0
Foreign currency translation adjustments	0	0
Ending balance	$ 204,656	$ 204,656

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.