Company Overview	6 Months Ended
Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Company Overview	1. Company Overview Beacon Roofing Supply, Inc. (the “Company”) was incorporated in the state of Delaware on August 22, 1997 and is the largest publicly traded distributor of residential and non-residential roofing materials and complementary building products in the United States and Canada. On January 2, 2018, the Company completed the acquisition of all the outstanding capital stock of Allied Building Products Corp. (“Allied”), a New Jersey corporation, for $2.625 billion, subject to certain working capital and other adjustments. Allied engages in the distribution of roofing materials, drywall, ceiling tile, and related accessories in the United States and was a wholly-owned subsidiary of Oldcastle Distribution, Inc. (see Note 3 for further discussion). The Company operates its business under regional and local trade names and, as of March 31, 2019, the Company serviced customers in all 50 states within the United States and 6 provinces in Canada. The Company’s material subsidiaries are Beacon Sales Acquisition, Inc. and Beacon Roofing Supply Canada Company.

Company Overview

6 Months Ended

Mar. 31, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Company Overview

Beacon Roofing Supply, Inc. (the “Company”) was incorporated in the state of Delaware on August 22, 1997 and is the largest publicly traded distributor of residential and non-residential roofing materials and complementary building products in the United States and Canada.

On January 2, 2018, the Company completed the acquisition of all the outstanding capital stock of Allied Building Products Corp. (“Allied”), a New Jersey corporation, for $2.625 billion, subject to certain working capital and other adjustments. Allied engages in the distribution of roofing materials, drywall, ceiling tile, and related accessories in the United States and was a wholly-owned subsidiary of Oldcastle Distribution, Inc. (see Note 3 for further discussion).

The Company operates its business under regional and local trade names and, as of March 31, 2019, the Company serviced customers in all 50 states within the United States and 6 provinces in Canada. The Company’s material subsidiaries are Beacon Sales Acquisition, Inc. and Beacon Roofing Supply Canada Company.