Acquisition-Related Liabilities - Additional Information (Detail) - Summit Materials, LLC [Member]	12 Months Ended
Jan. 02, 2016
Minimum [Member]
Business Acquisition [Line Items]
Period identified for deferred consideration due	5 years
Maximum [Member]
Business Acquisition [Line Items]
Period identified for deferred consideration due	20 years

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_BusinessAcquisitionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration