v3.23.2

Cover	Sep. 07, 2023
Entity Information [Line Items]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Sep. 07, 2023
Entity File Number	001-36873
Entity Registrant Name	Summit Materials, LLC
Entity Central Index Key	0001571371
Entity Tax Identification Number	47-1984212
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	1801 California Street
Entity Address, Address Line Two	Suite 3500
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80202
City Area Code	303
Local Phone Number	893-0012
Written Communications	false
Soliciting Material	true
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Title of 12(b) Security	Class A Common Stock (par value, $0.01 per share)
Trading Symbol	SUM
Security Exchange Name	NYSE
Entity Emerging Growth Company	false
Summit Materials Inc [Member]
Entity Information [Line Items]
Entity Registrant Name	Summit Materials, Inc.
Summit Materials L L C [Member]
Entity Information [Line Items]
Entity File Number	333-187556
Entity Tax Identification Number	26-4138486
Entity Incorporation, State or Country Code	DE

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For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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Address Line 1 such as Attn, Building Name, Street Name

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Name of the state or province.

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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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 exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Local phone number for entity.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Trading symbol of an instrument as listed on an exchange.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Summit Materials, LLC 8-K