Percentage of par value on senior notes.

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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- Details

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Debt - Senior Notes - Additional Information (Details) - USD ($) $ in Thousands			9 Months Ended	12 Months Ended
	Jun. 01, 2017	Mar. 08, 2016	Sep. 30, 2017	Jan. 02, 2016	Dec. 31, 2016
Debt
Write off of deferred financing fees			$ 45
8 1/2% Senior Notes, due 2022
Debt
Senior notes, interest rate (as a percent)			8.50%		8.50%
6 1/8% Senior Notes, due 2023
Debt
Senior notes, interest rate (as a percent)			6.125%		6.125%
5 1/8% Senior Notes, due 2025
Debt
Senior notes, interest rate (as a percent)			5.125%
Issuers
Debt
Debt instrument, face amount	$ 300,000
Senior notes, interest rate (as a percent)	5.125%
Percentage of par value of senior notes	100.00%
Proceeds net of related fees and expenses	$ 295,400
Issuers \| 8 1/2% Senior Notes, due 2022
Debt
Debt instrument, face amount		$ 250,000
Senior notes, interest rate (as a percent)		8.50%
Percentage of par value of senior notes		100.00%
Proceeds net of related fees and expenses		$ 246,300
Issuers \| 6 1/8% Senior Notes, due 2023
Debt
Debt instrument, face amount				$ 650,000
Senior notes, interest rate (as a percent)				6.125%
Issuers \| 6 1/8% Senior Notes, due 2023, issued at par
Debt
Debt instrument, face amount				$ 350,000
Issuers \| 6 1/8% Senior Notes, due 2023, , issued at 99.375% of par
Debt
Debt instrument, face amount				$ 300,000
Percentage of par value of senior notes				99.375%
Summit Materials, LLC
Debt
Write off of deferred financing fees			$ 45
Summit Materials, LLC \| 8 1/2% Senior Notes, due 2022
Debt
Senior notes, interest rate (as a percent)			8.50%		8.50%
Summit Materials, LLC \| 6 1/8% Senior Notes, due 2023
Debt
Senior notes, interest rate (as a percent)			6.125%		6.125%
Summit Materials, LLC \| 5 1/8% Senior Notes, due 2025
Debt
Senior notes, interest rate (as a percent)			5.125%