REVENUE RECOGNITION - Summary of Accounts Receivable, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Dec. 28, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 195,623	$ 191,672
Construction contract receivables	22,074	47,966
Retention receivables	18,141	17,808
Receivables from related parties	1,585	1,596
Accounts receivable	237,423	259,042
Less: Allowance for doubtful accounts	(6,208)	(5,786)
Accounts receivable, net	$ 231,215	253,256
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
General collection and billing period for retention receivables	1 year
Summit Materials, LLC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 195,623	191,672
Construction contract receivables	22,074	47,966
Retention receivables	18,141	17,808
Receivables from related parties	1,585	1,596
Accounts receivable	237,423	259,042
Less: Allowance for doubtful accounts	(6,208)	(5,786)
Accounts receivable, net	$ 231,215	$ 253,256
Summit Materials, LLC | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
General collection and billing period for retention receivables	1 year