Debt - Summary of Activity for Deferred Financing Fees (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Deferred finance costs
Beginning balance	$ 18,290	$ 15,892
Loan origination fees	5,317	5,675
Amortization	(2,945)	(2,503)
Write off of deferred financing fees	(45)
Ending balance	20,617	19,064
Summit Materials, LLC
Deferred finance costs
Beginning balance	18,290	15,892
Loan origination fees	5,317	5,675
Amortization	(2,945)	(2,503)
Write off of deferred financing fees	(45)
Ending balance	$ 20,617	$ 19,064