Accrued Expenses - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Schedule Of Accrued Expenses [Line Items]
Interest	$ 24,095	$ 22,991
Payroll and benefits	33,915	30,546
Capital lease obligations	19,276	11,766
Insurance	11,455	11,966
Non-income taxes	7,236	5,491
Professional fees	1,717	2,459
Other	18,935	26,386
Total	116,629	111,605
Summit Materials, LLC
Schedule Of Accrued Expenses [Line Items]
Interest	24,095	22,991
Payroll and benefits	33,915	30,546
Capital lease obligations	19,276	11,766
Insurance	11,455	11,966
Non-income taxes	7,467	5,491
Professional fees	1,717	2,459
Other	18,349	25,254
Total	$ 116,274	$ 110,473