Redeemable Noncontrolling Interest - Additional Information (Detail) - Summit Materials, LLC [Member] - Continental Cement Company, L.L.C. [Member] - USD ($) $ in Millions	12 Months Ended
Jan. 02, 2016	May 31, 2010
Redeemable Noncontrolling Interest [Line Items]
Aggregate consideration for acquiring noncontrolling interests	$ 64.1
Aggregate principal amount of non-interest bearing notes payable	15.0
Annual installments amount of non-interest bearing notes payable	2.5
Cash consideration	$ 35.0
Class A Units [Member]
Redeemable Noncontrolling Interest [Line Items]
Number of class units issued	100
Economic interest of redeemable noncontrolling interest, approximately	70.00%
Class B Units [Member]
Redeemable Noncontrolling Interest [Line Items]
Number of class units issued		100,000,000
Redeemable noncontrolling interest percentage, approximately		30.00%
Common Class A [Member]
Redeemable Noncontrolling Interest [Line Items]
Class A common shares	1,029,183

Initial public offering cash paid installments.

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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The number of each class of partnership units outstanding at the balance sheet date. Units represent shares of ownership of the general, limited, and preferred partners.

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- Definition

The cash outflow for the purchase of amounts due from customers, clients, lessees, borrowers, or others under the terms of its agreements therewith.

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The cash outflow to acquire an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among myriad other features and characteristics.

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Amount of cash outflow to a noncontrolling interest. Includes, but not limited to, reduction of noncontrolling interest ownership. Excludes dividends paid to the noncontrolling interest.

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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.

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The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

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