Acquisition-Related Liabilities - Remaining Payments Due under Noncompete and Deferred Consideration Agreements (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Business Combinations [Abstract]
2017	$ 14,967
2018	12,827
2019	8,362
2020	7,228
2021	7,228
Thereafter	6,813
Total scheduled payments	57,425
Present value adjustments	(12,264)
Total noncompete obligations and deferred consideration	45,161
Summit Materials, LLC
Business Combinations [Abstract]
2017	12,467
2018	10,327
2019	5,862
2020	4,728
2021	4,728
Thereafter	6,813
Total scheduled payments	44,925
Present value adjustments	(9,766)
Total noncompete obligations and deferred consideration	$ 35,159