Leasing Arrangements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Operating Leased Assets [Line Items]
Rent expense, including short-term rentals	$ 25.2	$ 21.7	$ 18.6
Royalty expense recorded in cost of revenue	20.1	18.7	15.6
Summit Materials, LLC
Operating Leased Assets [Line Items]
Rent expense, including short-term rentals	25.2	21.7	18.6
Royalty expense recorded in cost of revenue	$ 20.1	$ 18.7	$ 15.6