Beacon Roofing Supply (BECN) 10-Q 9 Feb 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Dec. 31, 2017	Jan. 31, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	BECN
Entity Registrant Name	BEACON ROOFING SUPPLY INC
Entity Central Index Key	1,124,941
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		68,011,206

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 63,827	$ 138,250	$ 73,271
Restricted cash	1,300,000
Accounts receivable, less allowance of $13,470, $11,829 and $16,711 as of December 31, 2017, September 30, 2017 and December 31, 2016, respectively	552,703	704,527	489,898
Inventories, net	603,793	551,924	528,709
Prepaid expenses and other current assets	218,718	209,138	209,651
Total current assets	2,739,041	1,603,839	1,301,529
Property and equipment, net	154,687	156,129	147,340
Goodwill	1,251,825	1,251,986	1,197,550
Intangibles, net	410,857	429,069	444,210
Other assets, net	8,868	8,534	1,511
Total Assets	4,565,278	3,449,557	3,092,140
Current liabilities:
Accounts payable	315,442	503,697	336,837
Accrued expenses	266,049	261,297	166,479
Current portions of long-term debt	14,239	14,141	14,610
Total current liabilities	595,730	779,135	517,926
Borrowings under revolving lines of credit, net	0	3,205	332,679
Long-term debt, net	2,000,059	721,268	722,516
Deferred income taxes, net and other	93,451	138,383	136,260
Long-term obligations under equipment financing and other, net	23,694	25,760	32,915
Total liabilities	2,712,934	1,667,751	1,742,296
Commitments and contingencies
Stockholders' equity:
Common stock (voting); $.01 par value; 100,000,000 shares authorized; 67,972,383 issued and outstanding as of December 31, 2017; 67,700,858 issued and outstanding as of September 30, 2017; 60,030,516 issued and outstanding at December 31, 2016	679	677	600
Undesignated preferred stock; 5,000,000 shares authorized, none issued or outstanding	0	0	0
Additional paid-in capital	1,050,389	1,047,506	701,542
Retained earnings	815,782	748,186	667,752
Accumulated other comprehensive loss	(14,506)	(14,563)	(20,050)
Total stockholders' equity	1,852,344	1,781,806	1,349,844
Total Liabilities and Stockholders' Equity	$ 4,565,278	$ 3,449,557	$ 3,092,140

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Accounts receivable, allowances	$ 13,470	$ 11,829	$ 16,711
Common stock (voting), par value	$ 0.01	$ 0.01	$ 0.01
Common stock (voting), shares authorized	100,000,000	100,000,000	100,000,000
Common Stock (Voting), issued	67,972,383	67,700,858	60,030,516
Common Stock (voting), outstanding	67,972,383	67,700,858	60,030,516
Undesignated Preferred Stock, shares authorized	5,000,000	5,000,000	5,000,000
Undesignated Preferred Stock, issued	0	0	0
Undesignated Preferred Stock, outstanding	0	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net sales	$ 1,121,979	$ 1,002,184
Cost of products sold	852,226	751,117
Gross profit	269,753	251,067
Operating expense	220,657	204,110
Income from operations	49,096	46,957
Interest expense, financing costs, and other	22,568	13,574
Income before provision for income taxes	26,528	33,383
Provision for (benefit from) income taxes	(41,068)	12,953
Net income	$ 67,596	$ 20,430
Weighted-average common stock outstanding:
Basic	67,825,430	59,943,264
Diluted	69,244,678	60,993,080
Net income per share:
Basic	$ 1	$ 0.34
Diluted	$ 0.98	$ 0.33

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 67,596	$ 20,430
Other comprehensive income (loss):
Foreign currency translation adjustment	57	(1,652)
Total other comprehensive income (loss)	57	(1,652)
Comprehensive income	$ 67,653	$ 18,778

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Operating Activities
Net income		$ 67,596	$ 20,430
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		26,904	28,425
Stock-based compensation		3,459	3,816
Certain interest expense and other financing costs		707	1,418
Gain on sale of fixed assets		(319)	(312)
Deferred income taxes	[1]	(44,923)	788
Changes in operating assets and liabilities, net of the effects of businesses acquired:
Accounts receivable		151,365	136,895
Inventories		(52,024)	(48,019)
Prepaid expenses and other assets		(1,421)	(46,594)
Accounts payable and accrued expenses		(191,800)	(18,724)
Net cash provided by (used in) operating activities		(40,456)	78,123
Investing Activities
Purchases of property and equipment		(7,416)	(7,280)
Acquisition of businesses, net		0	(1,850)
Proceeds from the sale of assets		413	400
Net cash used in investing activities		(7,003)	(8,730)
Financing Activities
Borrowings under revolving lines of credit		17,402	355,057
Repayments under revolving lines of credit		(20,548)	(382,395)
Repayments under term loan		0	(1,125)
Borrowings under Senior Notes	[2]	1,300,000	0
Payment of debt issuance costs		(21,917)	0
Repayments under equipment financing facilities and other		(1,968)	(2,405)
Payment of issuance costs from secondary offering of common stock		(429)	0
Proceeds from issuance of common stock related to equity awards		3,781	3,460
Taxes paid related to net share settlement of equity awards		(3,925)	(297)
Net cash provided by (used in) financing activities		1,272,396	(27,705)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		640	197
Net increase in cash, cash equivalents, and restricted cash		1,225,577	41,885
Cash, cash equivalents, and restricted cash, beginning of period		138,250	31,386
Cash, cash equivalents, and restricted cash, end of period		1,363,827	73,271
Cash paid during the period for:
Interest		26,781	19,335
Income taxes, net of tax refunds		$ 22,130	$ 13,906
[1]	Includes impact of provisional amounts recognized relating to estimated impact of Tax Cuts and Jobs Act of 2017 – see Note 12
[2]	Gross funds from issuance of 2025 Senior Notes to finance the Company’s Allied Acquisition, presented as restricted cash on the Company’s consolidated balance sheet – see Note 8

Company Overview

Company Overview	3 Months Ended
	Dec. 31, 2017
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. The Company operates its business under regional and local trade names and, as of December 31, 2017, the Company serviced customers in 48 states within the United States and 6 provinces in Canada. The Company’s material subsidiaries are Beacon Sales Acquisition, Inc., Beacon Canada, Inc. and Beacon Roofing Supply Canada Company.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation Beacon Roofing Supply, Inc. (the “Company”) prepared the condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the requirements of the Securities and Exchange Commission (“SEC”). As permitted under those rules, certain footnotes or other financial information have been condensed or omitted. The balance sheet as of December 31, 2016 has been presented for a better understanding of the impact of seasonal fluctuations on the Company’s financial condition. In management’s opinion, the financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of the Company’s financial position and operating results. The results for the three-month periods ended December 31, 2017 are not necessarily indicative of the results to be expected for the twelve months ending September 30, 2018 (“fiscal year 2018” or “2018”). The three-month periods ended December 31, 2017 and 2016 each had 61 business days. These interim Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto contained in the Company’s fiscal year 2017 (“2017”) Annual Report on Form 10-K for the year ended September 30, 2017. Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Significant items subject to such estimates include inventories, purchase price allocations, recoverability of goodwill and intangibles, and income taxes. Actual amounts could differ from those estimates. Recent Accounting Pronouncements—Adopted In July 2015, the FASB issued ASU 2015-11, “ Inventory: Simplifying the Measurement of Inventory. ” This guidance applies to inventory valued at first-in, first-out (FIFO) or average cost and requires inventory to be measured at the lower of cost and net realizable value, rather than at the lower of cost or market. This new standard is effective on a prospective basis for annual and interim reporting periods beginning after December 15, 2016. The Company adopted this guidance effective October 1, 2017 and the standard did not have a no material impact on the Company’s financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, “ Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting.” In November 2016, the FASB issued ASU 2016-18, “ Restricted Cash.” Recent Accounting Pronouncements—Not Yet Adopted In May 2014, the FASB issued ASU 2014-09, “ Revenue from Contracts with Customers In February 2016, the FASB issued ASU 2016-02, “ Leases In June 2016, the FASB issued ASU 2016-13, “ Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments.” In January 2017, the FASB issued ASU 2017-01, “ Business Combinations: Clarifying the Definition of a Business.” In January 2017, the FASB issued ASU 2017-04, “ Simplifying the Accounting for Goodwill Impairment.” In May 2017, the FASB issued ASU 2017-09, “Scope of Modification Accounting.”

Acquisitions

Acquisitions	3 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Acquisitions	3. Acquisitions During fiscal year 2017, the Company acquired 23 branches from the following five acquisitions: • On December 16, 2016, the Company purchased certain assets of BJ Supply Company, a distributor of roofing and related building products with 1 branch serving Pennsylvania and New Jersey and annual sales of approximately $4 million. The Company has finalized the acquisition accounting entries for this transaction. • On January 3, 2017, the Company acquired American Building & Roofing, Inc., a distributor of mainly residential roofing and related building products with 7 branches around Washington State and annual sales of approximately $36 million. • On January 9, 2017, the Company acquired Eco Insulation Supply, a distributor of insulation and related accessories with 1 branch serving Connecticut, Southern New England and the New York City metropolitan area and annual sales of approximately $8 million. • On March 1, 2017, the Company acquired Acme Building Materials, Inc., a distributor of residential roofing and related building products with 3 branches in Eastern Michigan and annual sales of approximately $13 million. • On May 1, 2017, the Company purchased certain assets of Lowry’s Inc., a distributor of waterproofing and concrete restoration materials with 11 branches operating in California, Arizona, Utah and Hawaii and annual sales of approximately $76 million. The Company recorded the acquired assets and liabilities related to these transactions at their estimated fair values as of the respective acquisition dates, with resulting goodwill of $53.0 million (all of which is deductible for tax purposes) and $47.4 million in intangible assets associated with these other acquisitions. For those acquisitions where the acquisition accounting entries have yet to be finalized, the Company’s allocation of the purchase price is subject to change on receipt of additional information, including, but not limited to, the finalization of asset valuations (intangible and fixed) and income tax accounting.

Net Income per Share

Net Income per Share	3 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Net Income per Share	4. Net Income per Share Basic net income per common share is computed by dividing net income by the weighted-average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the weighted-average number of common shares and dilutive common share equivalents then outstanding using the treasury stock method. Common share equivalents consist of the incremental common shares issuable upon the exercise of stock options and vesting of restricted stock awards. The following table presents the basic and diluted weighted-average shares outstanding for each period presented: Three Months Ended December 31, 2017 2016 Weighted-average common shares outstanding, basic 67,825,430 59,943,264 Effect of dilutive securities: Stock options 914,724 649,644 Restricted stock units 504,524 400,172 Weighted-average common shares outstanding, diluted 69,244,678 60,993,080 The following table includes the number of shares that may be dilutive common shares in the future. These shares were not included in the computation of diluted net income per share because the effect was either anti-dilutive or the requisite performance conditions were not met. Three Months Ended December 31, 2017 2016 Stock options 288,275 561,741 Restricted stock units - 247,559

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	5. Stockholders’ Equity The following table presents the activity included in stockholders’ equity during the three months ended December 31, 2017 (in thousands, except share amounts): Accumulated Common Stock Additional Paid-in Retained Other Comprehensive Total Stockholders' Shares Amount Capital Earnings Loss Equity Balance at September 30, 2017 67,700,858 $ 677 $ 1,047,506 $ 748,186 $ (14,563 ) $ 1,781,806 Issuance of common stock, net of shares withheld for taxes 271,525 2 (147 ) - - (145 ) Issuance costs related to secondary offering of common stock (429 ) (429 ) Stock-based compensation - - 3,459 - - 3,459 Other comprehensive income - - - - 57 57 Net income - - - 67,596 - 67,596 Balance at December 31, 2017 67,972,383 $ 679 $ 1,050,389 $ 815,782 $ (14,506 ) $ 1,852,344 Common and Preferred Stock The Company is authorized to issue 100 million shares of common stock and 5 million shares of preferred stock. As of December 31, 2017, September 30, 2017, and December 31, 2016 there were 67,972,383, 67,700,858 and 60,030,516 shares of common stock issued and outstanding, respectively, and no preferred stock outstanding as of any period end. Accumulated Other Comprehensive Loss Other comprehensive income (loss) is comprised of certain gains and losses that are excluded from net income under GAAP and instead recorded as a separate element of stockholders’ equity. The Company’s other comprehensive income (loss) consists of foreign currency translation adjustments as well as unrealized gains or losses on the Company’s derivative contracts. The following table summarizes the components of and changes in accumulated other comprehensive loss (in thousands): Foreign Currency Translation Accumulated Other Comprehensive Loss Balance as of September 30, 2017 $ (14,563 ) $ (14,563 ) Other comprehensive income before reclassifications 57 57 Reclassifications out of other comprehensive loss - - Balance as of December 31, 2017 $ (14,506 ) $ (14,506 )

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	6. Stock-based Compensation On February 9, 2016, the shareholders of the Company approved the Amended and Restated Beacon Roofing Supply, Inc. 2014 Stock Plan (the “2014 Plan”). The 2014 Plan provides for discretionary awards of stock options, stock awards, restricted stock units, and stock appreciation rights (“SARs”) for up to 5,000,000 shares of common stock to selected employees and non-employee directors. The 2014 Plan mandates that all forfeited, expired, and withheld shares, including those from the predecessor plans, be returned to the 2014 Plan and made available for issuance. As of December 31, 2017, there were 3,638,039 shares of common stock available for issuance. Prior to the 2014 Plan, the Company maintained the amended and restated Beacon Roofing Supply, Inc. 2004 Stock Plan (the “2004 Plan”). Upon shareholder approval of the 2014 Plan, the Company ceased issuing equity awards from the 2004 Plan and mandated that all future equity awards will be issued from the 2014 Plan. For all equity awards granted prior to October 1, 2014, in the event of a change in control of the Company, all awards are immediately vested. Beginning in fiscal 2015, equity awards contained a “double trigger” change in control mechanism. Unless an award is continued or assumed by a public company in an equitable manner, an award shall become fully vested immediately prior to a change in control (at 100% in the case of a performance-based restricted stock award). If an award is so continued or assumed, vesting will continue in accordance with the terms of the award, unless there is a qualifying termination within one-year following the change in control, in which event the award shall become fully vested immediately (at 100% in the case of a performance-based restricted stock award). Stock Options Non-qualified stock options generally expire 10 years after the grant date and, except under certain conditions, the options are subject to continued employment and vest in three annual installments over the three-year period following the grant dates. The fair values of the options granted during the three months ended December 31, 2017 were estimated on the dates of grants using the Black-Scholes option-pricing model with the following weighted-average assumptions: Risk-free interest rate 2.10 % Expected volatility 26.43 % Expected life (in years) 5.46 Dividend yield - The following table summarizes all stock option activity for the three months ended December 31, 2017 (in thousands, except share, per share, and time period amounts): Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value 1 Balance as of September 30, 2017 2,084,228 $ 28.84 6.1 $ 46,714 Granted 276,370 55.17 Exercised (154,588 ) 24.46 Canceled/Forfeited (7,711 ) 38.05 Expired (2,274 ) 14.56 Balance as of December 31, 2017 2,196,025 $ 32.44 6.4 $ 68,776 Vested and expected to vest after December 31, 2017 2,168,798 $ 32.25 6.4 $ 68,339 Exercisable as of December 31, 2017 1,582,337 $ 27.40 5.4 $ 57,537 1 Aggregate intrinsic value as represents the difference between the closing fair value of the underlying common stock and the exercise price of outstanding, in-the-money options on the date of measurement. During the three months ended December 31, 2017 and 2016, the Company recorded stock-based compensation expense related to stock options of $1.1 million and $1.3 million, respectively. As of December 31, 2017, there was $8.0 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted-average period of 2.3 years. The following table summarizes additional information on stock options for the period presented (in thousands, except per share amounts): Three Months Ended December 31, 2017 2016 Weighted-average fair value of stock options granted $ 15.86 $ 14.21 Total fair value of stock options vested 3,773 4,887 Total intrinsic value of stock options exercised 5,448 2,750 Restricted Stock Units Restricted stock unit (“RSU”) awards granted to employees are subject to continued employment and generally vest after three years. The Company also grants certain RSU awards to management that contain an additional vesting condition tied directly to a defined performance metric for the Company. The actual number of RSUs that will vest can range from 0% to 150% of the grant, depending upon actual Company performance below or above the established target level. The Company estimates performance in relation to the target when determining the projected number of RSUs that will vest and calculating the stock-based compensation cost related to these awards. RSUs granted to non-employee directors are subject to continued service and vest after one year (except under certain conditions). Generally, the common shares underlying the RSUs are not eligible for distribution until the director’s service on the Board has terminated. For non-employee director RSU grants made prior to fiscal year 2014, the share distribution date is six months after the director’s termination of service on the board. RSU grants made in fiscal year 2014 and thereafter have no such holding period requirement. Additionally, beginning in fiscal year 2016 non-employee directors holding common stock and outstanding vested unexercised/unsettled equity awards with a fair value that is greater than or equal to five times the annual cash retainer may elect to have future grants settle simultaneously with vesting. The following table summarizes all restricted stock unit activity for the period presented: RSUs Outstanding Weighted- Average Grant Date Fair Value Balance at September 30, 2017 770,973 $ 38.95 Granted 160,510 55.17 Performance awards 1 41,440 39.56 Released (184,771 ) 31.31 Canceled/Forfeited (7,206 ) 40.65 Balance at December 31, 2017 780,946 $ 44.11 Vested and expected to vest after December 31, 2017 748,271 $ 43.92 1 Additional restricted stock units outstanding as a result of the satisfaction of a performance vesting condition prior to the ascribed time-based vesting condition (release date). During the three months ended December 31, 2017 and 2016, the Company recorded stock-based compensation expense related to restricted stock units of $2.4 million and $2.5 million, respectively. As of December 31, 2017, there was $18.2 million of unrecognized compensation cost related to unvested restricted stock units, which is expected to be recognized over a weighted-average period of 2.1 years. The following table summarizes additional information on RSUs for the period presented (in thousands): Three Months Ended December 31, 2017 2016 Weighted-average fair value of RSUs granted $ 55.17 $ 47.40 Total fair value of RSUs vested 5,786 1,002 Total intrinsic value of RSUs released 10,683 1,096

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	7. Goodwill and Intangible Assets Goodwill The following table sets forth the change in the carrying amount of goodwill for the Company during the three months ended December 31, 2017 and 2016, respectively (in thousands): Balance at September 30, 2016 $ 1,197,565 Acquisitions 774 Translation and other adjustments (789 ) Balance at December 31, 2016 $ 1,197,550 Balance at September 30, 2017 $ 1,251,986 Acquisitions - Translation and other adjustments (161 ) Balance at December 31, 2017 $ 1,251,825 The change in the carrying amount of goodwill for the three months ended December 31, 2017 was driven by foreign currency translation adjustments. Intangible Assets In connection with transactions finalized during fiscal year 2017, the Company recorded intangible assets of $47.4 million ($42.7 million of customer relationships, $4.6 million of amortizable trademarks, and $0.1 million of beneficial lease arrangements). Intangible assets consisted of the following (in thousands, except time period amounts): December 31, 2017 September 30, 2017 December 31, 2016 Weighted- Average Remaining Life 1 (Years) Amortizable intangible assets: Non-compete agreements $ 2,824 $ 2,824 $ 2,824 3.10 Customer relationships 609,984 610,026 567,157 17.36 Trademarks 10,500 10,500 5,900 8.17 Beneficial lease arrangements 1,060 1,060 960 8.65 Total amortizable intangible assets 624,368 624,410 576,841 Less: Accumulated amortization (286,561 ) (268,391 ) (205,681 ) Total amortizable intangible assets, net $ 337,807 $ 356,019 $ 371,160 Indefinite lived trademarks 73,050 73,050 73,050 Total intangibles, net $ 410,857 $ 429,069 $ 444,210 1 As of December 31, 2017 For the three month periods ended December 31, 2017 and 2016, we recorded $18.2 million and $20.1 million of amortization expense relating to the above-listed intangible assets, respectively. The intangible asset lives range from 5 to 20 years and have a weighted-average remaining life of 17.1 years as of December 31, 2017. The following table presents the estimated annual amortization expense for these intangible assets (in thousands): Year Ending September 30, 2018 (Jan - Sept) $ 53,374 2019 58,774 2020 47,754 2021 38,234 2022 30,289 Thereafter 109,382 $ 337,807

Financing Arrangements

Financing Arrangements	3 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Financing Arrangements	8. Financing Arrangements The following table summarizes all financing arrangements the Company has entered into (in thousands): December 31, September 30, December 31, 2017 2017 2016 Senior Secured Credit Facility Revolving Lines of Credit: U.S. Revolver, expires October 1, 2020 1 $ - $ - $ 330,445 Canadian Revolver, expires October 1, 2020 2 - 3,205 2,234 Term Loan, matures October 1, 2022 3 433,828 433,440 435,647 Total borrowings under Senior Secured Credit Facility 433,828 436,645 768,326 Less: current portion (4,500 ) (4,500 ) (4,500 ) Total long-term borrowings under Senior Secured Credit Facility $ 429,328 $ 432,145 $ 763,826 Senior Notes Senior Notes, matures October 2023 4 292,648 292,328 291,369 Senior Notes, matures November 2025 5 1,278,083 - - Less: current portion - - - Total long-term borrowings under Senior Notes $ 1,570,731 $ 292,328 $ 291,369 Equipment Financing Facilities and Other Equipment financing facilities, various maturities through September 2021 6 $ 14,400 $ 15,445 $ 19,188 Capital lease obligations, various maturities through November 2021 7 19,033 19,956 23,837 Total obligations under equipment financing facilities and other 33,433 35,401 43,025 Less: current portion (9,739 ) (9,641 ) (10,110 ) Total long-term obligations under equipment financing facilities and other $ 23,694 $ 25,760 $ 32,915 1 Effective rates on borrowings are 1.50% as of December 31, 2017; 2.00% as of September 30, 2017; and 3.13% as of December 31, 2016 2 Effective rates on borrowings are 3.70% as of December 31, 2017; 3.70% as of September 30, 2017; and 3.20% as of December 31, 2016 3 Interest rate of 4.06% as of December 31, 2017; 3.50% as of September 30, 2017; 3.71% as of December 31, 2016 4 Interest rate of 6.38% as of December 31, 2017, September 30, 2017 and December 31, 2016 5 Interest rate of 4.88% as of December 31, 2017 6 Fixed interest rates ranging from 2.33% to 3.25% as of December 31, 2017, September 30, 2017, and December 31, 2016 7 Fixed interest rates ranging from 2.72% to 10.39% as of December 31, 2017, September 30, 2016, and December 31, 2016 Financing - Allied Acquisition On October 25, 2017, in connection with the financing for the Allied Acquisition (see Note 14), Beacon Escrow Corporation, a wholly owned subsidiary of the Company (the “Escrow Issuer”), completed a private offering of $1.30 billion aggregate principal amount of 4.875% Senior Notes due 2025 (the “2025 Senior Notes”) at an issue price of 100%. The 2025 Senior Notes bear interest at a rate of 4.875% per annum, payable semi-annually in arrears, beginning May 1, 2018. Management anticipates repaying the notes at the maturity date of November 1, 2025. The net proceeds from the 2025 Senior Notes were deposited into a segregated escrow account with U.S. Bank National Association, as escrow agent (the “Escrow Agent”), subject to the satisfaction of all conditions precedent to the consummation of the Allied Acquisition and certain other conditions set forth in an escrow agreement (the “Escrow Agreement”) with the Escrow Agent. There are conditions that must be satisfied prior to releasing these proceeds from escrow; therefore, these escrowed funds have been presented as restricted cash on the Company’s consolidated balance sheet as of December 31, 2017. The following table provides a reconciliation of cash, cash equivalents, and restricted cash from the Company’s balance sheet to the same amounts shown in the Company’s consolidated statement of cash flows for the three months ended December 31, 2017 (in thousands): December 31, 2017 Cash and cash equivalents $ 63,827 Restricted cash 1,300,000 Total cash, cash equivalents, and restricted cash $ 1,363,827 Per the terms of the Escrow Agreement, the net proceeds from the 2025 Senior Notes remained in escrow until they were used to fund a portion of the purchase price of the Allied Acquisition payable at closing on January 2, 2018. On the same date, (i) the Escrow Issuer merged with and into the Company, and the Company assumed all obligations under the 2025 Senior Notes; and (ii) all existing domestic subsidiaries of the Company (including the entities acquired in the Allied Acquisition) became guarantors of the 2025 Senior Notes. As of December 31, 2017, the outstanding balance on the 2025 Senior Notes, net of debt issuance fees, was $1.28 billion. Financing - RSG Acquisition On October 1, 2015, in connection with the RSG Acquisition, the Company entered into various financing arrangements totaling $1.45 billion. A “Senior Secured Credit Facility” was entered into that is comprised of an asset-based revolving line of credit (“ABL”) of $700.0 million ($350.0 million of which was drawn at closing) and a new $450.0 million term loan (“Term Loan”). The Company also raised an additional $300.0 million through the issuance of senior notes (the “2023 Senior Notes”). The proceeds from the Senior Secured Credit Facility and Senior Notes were used to provide working capital and funds for other general corporate purposes, to refinance or otherwise extinguish all third-party indebtedness for borrowed money under Company’s and RSG’s existing senior secured credit facilities and RSG’s unsecured senior notes due 2020, to finance the acquisition, and to pay fees and expenses associated with the RSG acquisition. The Company incurred financing costs totaling approximately $31.3 million. Asset-based Line of Credit (“ABL”) On October 1, 2015, the Company entered into a $700 million ABL with Wells Fargo Bank, N.A. and a syndicate of other lenders. This ABL consists of revolving loans in both the United States (“U.S. Revolver”) in the amount of $670.0 million and Canada (“Canada Revolver”) in the amount of $30.0 million. The ABL has a maturity date of October 1, 2020. The ABL has various borrowing tranches with an interest at rate of LIBOR plus a margin 125 basis points, 150 basis points or 175 basis points, based on the total outstanding balance of each tranche. The LIBOR rates can be fixed at one, three, six, or twelve month intervals and any non-fixed LIBOR amounts revert to a 4.75% base rate. As of December 31, 2017, the total balance outstanding on the ABL was immaterial, and the weighted-average interest rate was 1.50%. Unamortized debt issuance costs of $4.9 million related to the ABL are classified in “other assets, net” on the Company’s consolidated balance sheet as of December 31, 2017. The Company also has outstanding standby letters of credit related to the U.S. Revolver in the amount of $10.7 million as of December 31, 2017. The current unused commitment fees on the ABL are 0.25% per annum. There is one financial covenant under the ABL, which is a Consolidated Fixed Charge Ratio. The Consolidated Fixed Charge Ratio is calculated by dividing consolidated earnings before interest, taxes, depreciation and amortization (EBITDA) by Consolidated Fixed Charges (as defined in the agreement). Per the covenant, the Company’s Consolidated Fixed Charge Ratio must be a minimum of 1.00 at the end of each fiscal quarter, calculated on a trailing four quarter basis. The covenant is only applicable when the borrowing availability is less than 10% of the maximum loan cap or $60.0 million. The ABL is guaranteed jointly, severally, fully and unconditionally by the Company’s active United States subsidiary. Term Loan On October 1, 2015, the Company entered into a $450.0 million Term Loan with Citibank N.A., and a syndicate of other lenders. The Term Loan requires quarterly principal payments in the amount of $1.1 million, with the remaining outstanding principal to be paid on its maturity date of October 1, 2022. The interest rate paid is based on a LIBOR rate (with a floor) plus a fixed spread. The Company has the option of selecting a LIBOR period that determines the rate at which interest can accrue on the Term Loan as well as the period in which interest payments are made. On September 16, 2016, the Company refinanced its Term Loan, lowering the LIBOR floor by 25 basis points and lowering the spread by 25 basis points. As a result of the refinancing, the Company wrote off $1.6 million of debt issuance costs in interest expense. As of December 31, 2017, the outstanding balance on the Term Loan, net of debt issuance fees, was $433.8 million. The Term Loan is guaranteed jointly, severally, fully and unconditionally by the Company’s active United States subsidiary. 2023 Senior Notes On October 1, 2015, the Company raised $300.0 million by issuing senior notes due 2023 (the “2023 Senior Notes”). The 2023 Senior Notes have a coupon rate of 6.38% per annum and are payable semi-annually in arrears, beginning April 1, 2016. There are early payment provisions in the indenture in which the Company would be subject to “make whole” provisions. Management anticipates repaying the notes at the maturity date of October 1, 2023. As of December 31, 2017, the outstanding balance on the 2023 Senior Notes, net of debt issuance fees, was $292.6 million. The 2023 Senior Notes are guaranteed jointly, severally, fully and unconditionally by the Company’s active United States subsidiary. Equipment Financing Facilities and Other As of December 31, 2017, the Company had a $14.4 million outstanding under equipment financing facilities, with fixed interest rates ranging from 2.33% to 3.25% and payments due through September 2021. As of December 31, 2017 the Company had $19.0 million of capital lease obligations outstanding. These leases have interest rates ranging from 2.72% to 10.39% with payments due through November 2021.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Operating Leases The Company mostly operates in leased facilities, which are accounted for as operating leases. The leases typically provide for a base rent plus real estate taxes. Certain of the leases provide for escalating rents over the lives of the leases and rent expense is recognized over the terms of those leases on a straight-line basis. For the three months ended December 31, 2017 and 2016, rent expense was $15.2 million and $14.2 million, respectively. Sublet income was immaterial for each of these periods. Contingencies The Company is subject to loss contingencies pursuant to various federal, state and local environmental laws and regulations; however, the Company is not aware of any reasonably possible losses that would have a material impact on its results of operations, financial position, or liquidity. Potential loss contingencies include possible obligations to remove or mitigate the effects on the environment of the placement, storage, disposal or release of certain chemical or other substances by the Company or by other parties. In connection with its acquisitions, the Company’s practice is to request indemnification for any and all known material liabilities of significance as of the respective dates of acquisition. Historically, environmental liabilities have not had a material impact on the Company’s results of operations, financial position or liquidity. The Company is subject to litigation from time to time in the ordinary course of business; however the Company does not expect the results, if any, to have a material adverse impact on its results of operations, financial position or liquidity.

Geographic Data

Geographic Data	3 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Geographic Data	10. Geographic Data The following tables summarize certain geographic information for the periods presented (in thousands): Three Months Ended December 31, 2017 2016 Net sales U.S. $ 1,076,262 $ 960,235 Canada 45,717 41,949 Total net sales $ 1,121,979 $ 1,002,184 December 31, September 30, December 31, 2017 2017 2016 Long-lived assets U.S. $ 488,137 $ 507,236 $ 507,295 Canada 13,225 13,446 12,716 Total long-lived assets $ 501,362 $ 520,682 $ 520,011

Fair Value Measurement

Fair Value Measurement	3 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurement	11. Fair Value Measurement As of December 31, 2017, the carrying amount of cash and cash equivalents, accounts receivable, prepaid and other current assets, accounts payable and accrued expenses approximated fair value because of the short-term nature of these instruments. The Company measures its cash equivalents at amortized cost, which approximates fair value based upon quoted market prices (Level 1). As of December 31, 2017, based upon recent trading prices (Level 2 — market approach), the fair value of the Company’s $300.0 million Senior Notes due in 2023 was $320.0 million and the fair value of the $1.30 billion Senior Notes due 2025 was $1.31 billion. As of December 31, 2017, the fair value of the Company’s Senior Secured Credit Facility approximated the amount outstanding. The Company estimates the fair value of its Senior Secured Credit Facility by discounting the future cash flows of each instrument using estimated market rates of debt instruments with similar maturities and credit profiles (Level 3).

Income Taxes

Income Taxes	3 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes On December 22, 2017, the U.S. federal government officially signed into law the Tax Cut and Jobs Act of 2017 (“TCJA”). ASC 740, Accounting for Income Taxes , requires companies to recognize the effect of tax law changes in the period of enactment even though the effective date for most provisions is for tax years beginning after December 31, 2017, or in the case of certain other provisions, January 1, 2018. Though certain key aspects of the new law are effective January 1, 2018 and have an immediate accounting effect, other significant provisions are not effective or may not result in accounting effects for September 30 fiscal year-end companies until October 1, 2018. Given the significance of the legislation, the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”), which allows registrants to record provisional amounts during a one year “measurement period” similar to that used when accounting for business combinations. Per SAB 118, the measurement period is deemed to have an earlier end date when the registrant has obtained, prepared and analyzed the information necessary to finalize its accounting. During the measurement period, impacts of the updated tax law are expected to be recorded at the time a reasonable estimate for all, or a portion, of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared or analyzed. SAB 118 states, that at each reporting period, companies must disclose the effects of the TCJA for areas where accounting is complete, disclose provisional amounts (or adjustments to provisional amounts) for the effects of the TCJA areas where accounting is not complete but a reasonable estimate has been determined, and confirm areas where a reasonable estimate of the effects cannot yet be made, and therefore taxes are reflected in accordance with law prior to the enactment of the TCJA. As of December 31, 2017, the Company was still assessing the overall impact that the TCJA will have on its financial statements and related disclosures; however, the Company was able to make the following reasonable estimates on the impact of the corporate taxation changes from the TCJA: • The company has a blended federal corporate income tax rate for fiscal year 2018 of 24.5%. This transitional tax rate stems from Section 15 of the Internal Revenue Code that states if the tax rate changes in during a tax year, the tax rate for the full year is calculated using the prior and revised tax rates on a proportional basis using the number of days under each legislated rate. For 2019, the Company will have a federal corporate income tax rate of 21%. • The Company remeasured its deferred tax assets and liabilities based on the revised corporate tax rate (21%). As a result, the Company recognized a provisional $47.4 million decrease of its deferred tax liabilities related to this remeasurement, which also resulted in the recognition of an income tax benefit for the same amount in its consolidated statement of operations for the three months ended December 31, 2017. The Company is not a calendar year-end filer; therefore it is required to determine which deferred taxes will be realized during fiscal year 2018 at the blended federal corporate income tax rate of 24.5% and which will be realized in future years at the federal corporate income tax rate of 21%. The Company will continue to refine its deferred tax remeasurement calculation and assess the related impact, which potentially could result in additional adjustments. • The Company estimated the impact of the mandatory repatriation transition tax on the net accumulated earnings and profits of the Company’s foreign subsidiary, Beacon Roofing Supply Canada Company (“BRSCC”). As a result, the Company recognized a provisional expense for the one-time transition tax liability of $0.9 million in its consolidated statement of operations for the three months ended December 31, 2017. The Company has not yet finalized its calculation of the repatriation transition tax, as it continues to analyze of the amount of BRSCC earnings held in cash and other specified assets that had been previously deferred from U.S. federal taxation. State conformity to the TCJA law changes has not been communicated by the state and local jurisdictions at this time; therefore, the Company has not made any provisional adjustments related to the potential impact in its financial statements. The Company will continue to account for items where a reasonable estimate of the impact could not be assessed as of December 31, 2017 under the guidance that was in effect immediately prior to the enactment of the TCJA, ASC 740, Accounting for Income Taxes.

Supplemental Guarantor Informat

Supplemental Guarantor Information	3 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Supplemental Guarantor Information	13. Supplemental Guarantor Information All of the Senior Notes issued on October 1, 2015 are guaranteed jointly and severally by all of the United States subsidiaries of the Company (collectively, the “Guarantors”), and not by the Canadian subsidiaries of the Company. Such guarantees are full and unconditional. Supplemental condensed consolidating financial information of the Company, including such information for the Guarantors, is presented below. The information is presented in accordance with the requirements of Rule 3-10 under the SEC’s Regulation S-X. The financial information may not necessarily be indicative of results of operations, cash flows or financial position had the non-guarantor subsidiaries operated as independent entities. Investments in subsidiaries are presented using the equity method of accounting. The principal elimination entries eliminate investments in subsidiaries and intercompany balances and transactions. Separate financial statements of the Guarantors are not provided as the consolidating financial information contained herein provides a more meaningful disclosure to allow investors to determine the nature of the assets held by, and the operations of, the combined groups. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Balance Sheets (Unaudited; In thousands) December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries 1 Eliminations and Other Consolidated Assets Current assets: Cash and cash equivalents $ - $ 70,698 $ 2,122 $ (8,993 ) $ 63,827 Restricted cash - - 1,300,000 - 1,300,000 Accounts receivable, net - 526,068 27,775 (1,140 ) 552,703 Inventories, net - 581,288 22,505 - 603,793 Prepaid expenses and other current assets 17,713 194,007 6,998 - 218,718 Total current assets 17,713 1,372,061 1,359,400 (10,133 ) 2,739,041 Intercompany receivable, net - 730,364 - (730,364 ) - Investments in consolidated subsidiaries 3,239,031 - - (3,239,031 ) - Deferred income taxes, net 18,286 - - (18,286 ) - Property and equipment, net 8,271 135,925 10,491 - 154,687 Goodwill - 1,220,813 31,012 - 1,251,825 Intangibles, net - 408,123 2,734 - 410,857 Other assets, net 3,341 5,527 - - 8,868 Total Assets $ 3,286,642 $ 3,872,813 $ 1,403,637 $ (3,997,814 ) $ 4,565,278 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 21,511 $ 296,547 $ 7,517 $ (10,133 ) $ 315,442 Accrued expenses 27,467 232,131 6,451 - 266,049 Current portions of long-term debt 4,500 9,739 - - 14,239 Total current liabilities 53,478 538,417 13,968 (10,133 ) 595,730 Intercompany payable, net 680,761 - 49,603 (730,364 ) - Borrowings under revolving lines of credit, net - - - - - Long-term debt, net 700,059 - 1,300,000 - 2,000,059 Deferred income taxes, net and other - 111,066 671 (18,286 ) 93,451 Long-term obligations under equipment financing and other, net - 23,624 70 - 23,694 Total liabilities 1,434,298 673,107 1,364,312 (758,783 ) 2,712,934 Total stockholders' equity 1,852,344 3,199,706 39,325 (3,239,031 ) 1,852,344 Total Liabilities and Stockholders' Equity $ 3,286,642 $ 3,872,813 $ 1,403,637 $ (3,997,814 ) $ 4,565,278 1 Includes $1.30 billion in restricted cash and long term debt related to the Allied Acquisition temporarily held in Beacon Escrow Corporation – see Note 8 for further details. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Balance Sheets (Unaudited; In thousands) September 30, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Assets Current assets: Cash and cash equivalents $ - $ 149,799 $ 1,582 $ (13,131 ) $ 138,250 Accounts receivable, net - 663,034 42,633 (1,140 ) 704,527 Inventories, net - 527,226 24,698 - 551,924 Prepaid expenses and other current assets 4,195 198,817 6,126 - 209,138 Total current assets 4,195 1,538,876 75,039 (14,271 ) 1,603,839 Intercompany receivable, net - 655,372 - (655,372 ) - Investments in consolidated subsidiaries 3,160,273 - - (3,160,273 ) - Deferred income taxes, net 30,822 - - (30,822 ) - Property and equipment, net 6,610 138,955 10,564 - 156,129 Goodwill - 1,220,812 31,174 - 1,251,986 Intangibles, net - 426,187 2,882 - 429,069 Other assets, net 2,912 5,622 - - 8,534 Total Assets $ 3,204,812 $ 3,985,824 $ 119,659 $ (3,860,738 ) $ 3,449,557 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 27,174 $ 468,891 $ 21,903 $ (14,271 ) $ 503,697 Accrued expenses 51,183 204,173 5,941 - 261,297 Current portions of long-term obligations 4,500 9,641 - - 14,141 Total current liabilities 82,857 682,705 27,844 (14,271 ) 779,135 Intercompany payable, net 618,881 - 36,491 (655,372 ) - Borrowings under revolving lines of credit, net - - 3,205 - 3,205 Long-term debt, net 721,268 - - - 721,268 Deferred income taxes, net - 168,209 996 (30,822 ) 138,383 Long-term obligations under equipment financing and other, net - 25,694 66 - 25,760 Total liabilities 1,423,006 876,608 68,602 (700,465 ) 1,667,751 Total stockholders' equity 1,781,806 3,109,216 51,057 (3,160,273 ) 1,781,806 Total Liabilities and Stockholders' Equity $ 3,204,812 $ 3,985,824 $ 119,659 $ (3,860,738 ) $ 3,449,557 BEACON ROOFING SUPPLY, INC. Condensed Consolidating Balance Sheets (Unaudited; In thousands) December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Assets Current assets: Cash and cash equivalents $ - $ 83,617 $ 3,606 $ (13,952 ) $ 73,271 Accounts receivable, net - 467,093 24,162 (1,357 ) 489,898 Inventories, net - 503,834 24,875 - 528,709 Prepaid expenses and other current assets 2,651 199,305 7,695 - 209,651 Total current assets 2,651 1,253,849 60,338 (15,309 ) 1,301,529 Intercompany receivable, net - 900,545 - (900,545 ) - Investments in consolidated subsidiaries 2,915,905 - - (2,915,905 ) - Deferred income taxes, net 58,561 - - (58,561 ) - Property and equipment, net 5,250 132,482 9,608 - 147,340 Goodwill - 1,168,575 28,975 - 1,197,550 Intangibles, net - 441,101 3,109 - 444,210 Other assets, net 1,243 268 - - 1,511 Total Assets $ 2,983,610 $ 3,896,820 $ 102,030 $ (3,890,320 ) $ 3,092,140 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 26,354 $ 313,647 $ 12,145 $ (15,309 ) $ 336,837 Accrued expenses 20,510 141,266 4,703 - 166,479 Current portions of long-term obligations 4,500 10,110 - - 14,610 Total current liabilities 51,364 465,023 16,848 (15,309 ) 517,926 Intercompany payable, net 859,886 - 40,659 (900,545 ) - Borrowings under revolving lines of credit - 330,444 2,235 - 332,679 Long-term debt, net 722,516 - - - 722,516 Deferred income taxes, net - 194,555 266 (58,561 ) 136,260 Long-term obligations under equipment financing and other, net - 32,869 46 - 32,915 Total liabilities 1,633,766 1,022,891 60,054 (974,415 ) 1,742,296 Total stockholders' equity 1,349,844 2,873,929 41,976 (2,915,905 ) 1,349,844 Total Liabilities and Stockholders' Equity $ 2,983,610 $ 3,896,820 $ 102,030 $ (3,890,320 ) $ 3,092,140 BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Operations (Unaudited; In thousands, except share and per share amounts) Three Months Ended December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries 1 Eliminations and Other Consolidated Net sales $ - $ 1,076,262 $ 45,717 $ - $ 1,121,979 Cost of products sold - 816,436 35,790 - 852,226 Gross profit - 259,826 9,927 - 269,753 Operating expense 323 210,755 9,579 - 220,657 Intercompany charges (income) 893 (893 ) - - - Income (loss) from operations (1,216 ) 49,964 348 - 49,096 Interest expense, financing costs, and other 10,076 825 11,667 - 22,568 Intercompany interest expense (income) (5,708 ) 5,321 387 - - Income (loss) before provision for income taxes (5,584 ) 43,818 (11,706 ) - 26,528 Provision for (benefit from) income taxes 5,521 (46,672 ) 83 - (41,068 ) Income (loss) before equity in net income of subsidiaries (11,105 ) 90,490 (11,789 ) - 67,596 Equity in net income of subsidiaries 78,701 - - (78,701 ) - Net income (loss) $ 67,596 $ 90,490 $ (11,789 ) $ (78,701 ) $ 67,596 Weighted-average common stock outstanding: Basic 67,825,430 Diluted 69,244,678 Net income per share: Basic $ 1.00 Diluted $ 0.98 1 Includes interest expense from $1.30 billion in long term debt related to the Allied Acquisition temporarily held in Beacon Escrow Corporation – see Note 8 for further details. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Operations (Unaudited; In thousands, except share and per share amounts) Three Months Ended December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net sales $ - $ 960,235 $ 41,949 $ - $ 1,002,184 Cost of products sold - 718,534 32,583 - 751,117 Gross profit - 241,701 9,366 - 251,067 Operating expenses 8,646 187,073 8,391 - 204,110 Intercompany charges (income) (11,953 ) 11,399 554 - - Income from operations 3,307 43,229 421 - 46,957 Interest expense, financing costs, and other 15,354 (2,545 ) 765 - 13,574 Intercompany interest expense (income) (5,593 ) 5,593 - - - Income (loss) before provision for income taxes (6,454 ) 40,181 (344 ) - 33,383 Provision for (benefit from) income taxes (2,854 ) 15,902 (95 ) - 12,953 Income (loss) before equity in net income of subsidiaries (3,600 ) 24,279 (249 ) - 20,430 Equity in net income of subsidiaries 24,030 - - (24,030 ) - Net income (loss) $ 20,430 $ 24,279 $ (249 ) $ (24,030 ) $ 20,430 Weighted-average common stock outstanding: Basic 59,943,264 Diluted 60,993,080 Net income per share: Basic $ 0.34 Diluted $ 0.33 BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Comprehensive Income (Unaudited; In thousands) Three Months Ended December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net income (loss) $ 67,596 $ 90,490 $ (11,789 ) $ (78,701 ) $ 67,596 Other comprehensive income: Foreign currency translation adjustment 57 - 57 (57 ) 57 Total other comprehensive income 57 - 57 (57 ) 57 Comprehensive income (loss) $ 67,653 $ 90,490 $ (11,732 ) $ (78,758 ) $ 67,653 Three Months Ended December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net income (loss) $ 20,430 $ 24,279 $ (249 ) $ (24,030 ) $ 20,430 Other comprehensive loss: Foreign currency translation adjustment (1,652 ) - (1,652 ) 1,652 (1,652 ) Total other comprehensive loss (1,652 ) - (1,652 ) 1,652 (1,652 ) Comprehensive income (loss) $ 18,778 $ 24,279 $ (1,901 ) $ (22,378 ) $ 18,778 BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Cash Flows (Unaudited; In thousands) Three Months Ended December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries 1 Eliminations and Other Consolidated Net cash provided by (used in) operating activities $ (37,331 ) $ 2,338 $ (9,658 ) $ 4,195 $ (40,456 ) Investing Activities Purchases of property and equipment (2,117 ) (4,874 ) (425 ) - (7,416 ) Acquisition of businesses - - - - - Proceeds from the sale of assets - 398 15 - 413 Intercompany activity 61,938 - - (61,938 ) - Net cash provided by (used in) investing activities 59,821 (4,476 ) (410 ) (61,938 ) (7,003 ) Financing Activities Borrowings under revolving lines of credit - 878 16,524 - 17,402 Repayments under revolving lines of credit - (877 ) (19,671 ) - (20,548 ) Repayments under term loan - - - - - Repayments under equipment financing facilities and other - (1,973 ) 5 - (1,968 ) Borrowings under Senior Notes - - 1,300,000 - 1,300,000 Payment of debt issuance costs (21,917 ) - - - (21,917 ) Payment of issuance costs from secondary offering of common stock (429 ) - - - (429 ) Proceeds from issuance of common stock related to equity awards 3,781 - - - 3,781 Taxes paid related to net share settlement of equity awards (3,925 ) - - - (3,925 ) Intercompany activity - (74,991 ) 13,110 61,881 - Net cash provided by (used in) financing activities (22,490 ) (76,963 ) 1,309,968 61,881 1,272,396 Effect of exchange rate changes on cash, cash equivalents, and restricted cash - - 640 - 640 Net increase (decrease) in cash, cash equivalents, and restricted cash - (79,101 ) 1,300,540 4,138 1,225,577 Cash, cash equivalents, and restricted cash, beginning of period - 149,799 1,582 (13,131 ) 138,250 Cash, cash equivalents, and restricted cash, end of period $ - $ 70,698 $ 1,302,122 $ (8,993 ) $ 1,363,827 1 Includes activity from $1.30 billion in long term debt related to the Allied Acquisition temporarily held in Beacon Escrow Corporation – see Note 8 for further details. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Cash Flows (Unaudited; In thousands) Three Months Ended December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net cash provided by (used in) operating activities $ (18,908 ) $ 100,962 $ 1,084 $ (5,015 ) $ 78,123 Investing Activities Purchases of property and equipment (1,006 ) (6,073 ) (201 ) - (7,280 ) Acquisition of businesses (1,850 ) - - - (1,850 ) Proceeds from the sale of assets - 388 12 - 400 Intercompany activity 19,726 - - (19,726 ) - Net cash provided by (used in) investing activities 16,870 (5,685 ) (189 ) (19,726 ) (8,730 ) Financing Activities Borrowings under revolving lines of credit - 352,807 2,250 - 355,057 Repayments under revolving lines of credit - (377,896 ) (4,499 ) - (382,395 ) Repayments under term loan (1,125 ) - - - (1,125 ) Repayments under equipment financing facilities and other - (2,405 ) - - (2,405 ) Proceeds from issuance of common stock 3,460 - - - 3,460 Taxes paid related to net share settlement of equity awards (297 ) - - - (297 ) Intercompany activity - (21,613 ) 1,887 19,726 - Net cash provided by (used in) financing activities 2,038 (49,107 ) (362 ) 19,726 (27,705 ) Effect of exchange rate changes on cash, cash equivalents, and restricted cash - - 197 - 197 Net increase (decrease) in cash, cash equivalents, and restricted cash - 46,170 730 (5,015 ) 41,885 Cash, cash equivalents, and restricted cash, beginning of period - 37,447 2,876 (8,937 ) 31,386 Cash, cash equivalents, and restricted cash, end of period $ - $ 83,617 $ 3,606 $ (13,952 ) $ 73,271

Subsequent Events

Subsequent Events	3 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events On January 2, 2017 (the “Closing Date”), the Company completed its previously announced acquisition (the “Allied Acquisition”) of all the outstanding capital stock of Allied Building Products Corp. and an affiliated entity (together, “Allied”), pursuant to that certain Stock Purchase Agreement, dated August 24, 2017 (the “Stock Purchase Agreement”), among the Company, Oldcastle, Inc., as parent, and Oldcastle Distribution, Inc., as seller, for approximately $2.625 billion in cash, subject to a working capital and certain other adjustments as set forth in the Stock Purchase Agreement (the “Purchase Price”). In connection with the Allied Acquisition, on the Closing Date the Company entered into (i) a new term loan agreement with Citibank, N.A., providing for a term loan B facility with an initial commitment of $970.0 million and (ii) an amended and restated credit agreement with Wells Fargo Bank, N.A., providing for a senior secured asset-based revolving credit facility with an initial commitment of $1.30 billion. Base borrowing rates on these facilities will be at LIBOR plus 1.25% and LIBOR plus 2.25%, respectively. In connection with the Allied Acquisition, on the Closing Date, the Company completed the sale of 400,000 shares of Series A Cumulative Convertible Participating Preferred Stock, par value $0.01 per share (the “Preferred Stock”), with an aggregate liquidation preference of $400.0 million, at a purchase price of $1,000 per share, to CD&R Boulder Holdings, L.P., pursuant to that certain Investment Agreement, dated as of August 24, 2017, with CD&R Boulder Holdings, L.P. and Clayton, Dubilier & Rice Fund IX, L.P. (solely for the purpose of limited provisions therein) (the “Convertible Preferred Stock Purchase”). The $400.0 million in proceeds from the Convertible Preferred Stock Purchase were used to finance, in part, the Purchase Price. The Preferred Stock is convertible perpetual participating preferred stock of the Company, with an initial conversion price of $41.26 per share, and will accrue dividends at a rate of 6.0% per annum (payable in cash or in-kind, subject to certain conditions.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Beacon Roofing Supply, Inc. (the “Company”) prepared the condensed consolidated financial statements in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information and the requirements of the Securities and Exchange Commission (“SEC”). As permitted under those rules, certain footnotes or other financial information have been condensed or omitted. The balance sheet as of December 31, 2016 has been presented for a better understanding of the impact of seasonal fluctuations on the Company’s financial condition. In management’s opinion, the financial statements include all normal and recurring adjustments that are considered necessary for the fair presentation of the Company’s financial position and operating results. The results for the three-month periods ended December 31, 2017 are not necessarily indicative of the results to be expected for the twelve months ending September 30, 2018 (“fiscal year 2018” or “2018”). The three-month periods ended December 31, 2017 and 2016 each had 61 business days. These interim Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto contained in the Company’s fiscal year 2017 (“2017”) Annual Report on Form 10-K for the year ended September 30, 2017.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Significant items subject to such estimates include inventories, purchase price allocations, recoverability of goodwill and intangibles, and income taxes. Actual amounts could differ from those estimates.
Recent Accounting Pronouncements - Adopted and Not Yet Adopted	Recent Accounting Pronouncements—Adopted In July 2015, the FASB issued ASU 2015-11, “ Inventory: Simplifying the Measurement of Inventory. ” This guidance applies to inventory valued at first-in, first-out (FIFO) or average cost and requires inventory to be measured at the lower of cost and net realizable value, rather than at the lower of cost or market. This new standard is effective on a prospective basis for annual and interim reporting periods beginning after December 15, 2016. The Company adopted this guidance effective October 1, 2017 and the standard did not have a no material impact on the Company’s financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, “ Compensation—Stock Compensation: Improvements to Employee Share-Based Payment Accounting.” In November 2016, the FASB issued ASU 2016-18, “ Restricted Cash.” Recent Accounting Pronouncements—Not Yet Adopted In May 2014, the FASB issued ASU 2014-09, “ Revenue from Contracts with Customers In February 2016, the FASB issued ASU 2016-02, “ Leases In June 2016, the FASB issued ASU 2016-13, “ Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments.” In January 2017, the FASB issued ASU 2017-01, “ Business Combinations: Clarifying the Definition of a Business.” In January 2017, the FASB issued ASU 2017-04, “ Simplifying the Accounting for Goodwill Impairment.” In May 2017, the FASB issued ASU 2017-09, “Scope of Modification Accounting.”

Net Income per Share (Tables)

Net Income per Share (Tables)	3 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Calculation of Weighted-Average Shares Outstanding	The following table presents the basic and diluted weighted-average shares outstanding for each period presented: Three Months Ended December 31, 2017 2016 Weighted-average common shares outstanding, basic 67,825,430 59,943,264 Effect of dilutive securities: Stock options 914,724 649,644 Restricted stock units 504,524 400,172 Weighted-average common shares outstanding, diluted 69,244,678 60,993,080
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following table includes the number of shares that may be dilutive common shares in the future. These shares were not included in the computation of diluted net income per share because the effect was either anti-dilutive or the requisite performance conditions were not met. Three Months Ended December 31, 2017 2016 Stock options 288,275 561,741 Restricted stock units - 247,559

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Stockholders Equity	The following table presents the activity included in stockholders’ equity during the three months ended December 31, 2017 (in thousands, except share amounts): Accumulated Common Stock Additional Paid-in Retained Other Comprehensive Total Stockholders' Shares Amount Capital Earnings Loss Equity Balance at September 30, 2017 67,700,858 $ 677 $ 1,047,506 $ 748,186 $ (14,563 ) $ 1,781,806 Issuance of common stock, net of shares withheld for taxes 271,525 2 (147 ) - - (145 ) Issuance costs related to secondary offering of common stock (429 ) (429 ) Stock-based compensation - - 3,459 - - 3,459 Other comprehensive income - - - - 57 57 Net income - - - 67,596 - 67,596 Balance at December 31, 2017 67,972,383 $ 679 $ 1,050,389 $ 815,782 $ (14,506 ) $ 1,852,344
Reclassification out of Accumulated Other Comprehensive Income	The following table summarizes the components of and changes in accumulated other comprehensive loss (in thousands): Foreign Currency Translation Accumulated Other Comprehensive Loss Balance as of September 30, 2017 $ (14,563 ) $ (14,563 ) Other comprehensive income before reclassifications 57 57 Reclassifications out of other comprehensive loss - - Balance as of December 31, 2017 $ (14,506 ) $ (14,506 )

Stock-based Compensation (Table

Stock-based Compensation (Tables)	3 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Fair Values of Options, Black-Scholes Option-Pricing Model, Weighted-Average Assumptions	The fair values of the options granted during the three months ended December 31, 2017 were estimated on the dates of grants using the Black-Scholes option-pricing model with the following weighted-average assumptions: Risk-free interest rate 2.10 % Expected volatility 26.43 % Expected life (in years) 5.46 Dividend yield -
Stock Options Outstanding and Activity During the Period	The following table summarizes all stock option activity for the three months ended December 31, 2017 (in thousands, except share, per share, and time period amounts): Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value 1 Balance as of September 30, 2017 2,084,228 $ 28.84 6.1 $ 46,714 Granted 276,370 55.17 Exercised (154,588 ) 24.46 Canceled/Forfeited (7,711 ) 38.05 Expired (2,274 ) 14.56 Balance as of December 31, 2017 2,196,025 $ 32.44 6.4 $ 68,776 Vested and expected to vest after December 31, 2017 2,168,798 $ 32.25 6.4 $ 68,339 Exercisable as of December 31, 2017 1,582,337 $ 27.40 5.4 $ 57,537 1 Aggregate intrinsic value as represents the difference between the closing fair value of the underlying common stock and the exercise price of outstanding, in-the-money options on the date of measurement.
Stock Option Grants, Vesting, and Exercises	The following table summarizes additional information on stock options for the period presented (in thousands, except per share amounts): Three Months Ended December 31, 2017 2016 Weighted-average fair value of stock options granted $ 15.86 $ 14.21 Total fair value of stock options vested 3,773 4,887 Total intrinsic value of stock options exercised 5,448 2,750
Restricted Shares and Units Outstanding and Activity During the Period	The following table summarizes all restricted stock unit activity for the period presented: RSUs Outstanding Weighted- Average Grant Date Fair Value Balance at September 30, 2017 770,973 $ 38.95 Granted 160,510 55.17 Performance awards 1 41,440 39.56 Released (184,771 ) 31.31 Canceled/Forfeited (7,206 ) 40.65 Balance at December 31, 2017 780,946 $ 44.11 Vested and expected to vest after December 31, 2017 748,271 $ 43.92 1 Additional restricted stock units outstanding as a result of the satisfaction of a performance vesting condition prior to the ascribed time-based vesting condition (release date).
Schedule Of Restricted Stock Units Additional Information	The following table summarizes additional information on RSUs for the period presented (in thousands): Three Months Ended December 31, 2017 2016 Weighted-average fair value of RSUs granted $ 55.17 $ 47.40 Total fair value of RSUs vested 5,786 1,002 Total intrinsic value of RSUs released 10,683 1,096

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Changes in goodwill	The following table sets forth the change in the carrying amount of goodwill for the Company during the three months ended December 31, 2017 and 2016, respectively (in thousands): Balance at September 30, 2016 $ 1,197,565 Acquisitions 774 Translation and other adjustments (789 ) Balance at December 31, 2016 $ 1,197,550 Balance at September 30, 2017 $ 1,251,986 Acquisitions - Translation and other adjustments (161 ) Balance at December 31, 2017 $ 1,251,825
Intangibles and Other Assets, Included in Other Long-term Assets	Intangible assets consisted of the following (in thousands, except time period amounts): December 31, 2017 September 30, 2017 December 31, 2016 Weighted- Average Remaining Life 1 (Years) Amortizable intangible assets: Non-compete agreements $ 2,824 $ 2,824 $ 2,824 3.10 Customer relationships 609,984 610,026 567,157 17.36 Trademarks 10,500 10,500 5,900 8.17 Beneficial lease arrangements 1,060 1,060 960 8.65 Total amortizable intangible assets 624,368 624,410 576,841 Less: Accumulated amortization (286,561 ) (268,391 ) (205,681 ) Total amortizable intangible assets, net $ 337,807 $ 356,019 $ 371,160 Indefinite lived trademarks 73,050 73,050 73,050 Total intangibles, net $ 410,857 $ 429,069 $ 444,210 1 As of December 31, 2017
Estimated Future Annual Amortization	The following table presents the estimated annual amortization expense for these intangible assets (in thousands): Year Ending September 30, 2018 (Jan - Sept) $ 53,374 2019 58,774 2020 47,754 2021 38,234 2022 30,289 Thereafter 109,382 $ 337,807

Financing Arrangements (Tables)

Financing Arrangements (Tables)	3 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	The following table summarizes all financing arrangements the Company has entered into (in thousands): December 31, September 30, December 31, 2017 2017 2016 Senior Secured Credit Facility Revolving Lines of Credit: U.S. Revolver, expires October 1, 2020 1 $ - $ - $ 330,445 Canadian Revolver, expires October 1, 2020 2 - 3,205 2,234 Term Loan, matures October 1, 2022 3 433,828 433,440 435,647 Total borrowings under Senior Secured Credit Facility 433,828 436,645 768,326 Less: current portion (4,500 ) (4,500 ) (4,500 ) Total long-term borrowings under Senior Secured Credit Facility $ 429,328 $ 432,145 $ 763,826 Senior Notes Senior Notes, matures October 2023 4 292,648 292,328 291,369 Senior Notes, matures November 2025 5 1,278,083 - - Less: current portion - - - Total long-term borrowings under Senior Notes $ 1,570,731 $ 292,328 $ 291,369 Equipment Financing Facilities and Other Equipment financing facilities, various maturities through September 2021 6 $ 14,400 $ 15,445 $ 19,188 Capital lease obligations, various maturities through November 2021 7 19,033 19,956 23,837 Total obligations under equipment financing facilities and other 33,433 35,401 43,025 Less: current portion (9,739 ) (9,641 ) (10,110 ) Total long-term obligations under equipment financing facilities and other $ 23,694 $ 25,760 $ 32,915 1 Effective rates on borrowings are 1.50% as of December 31, 2017; 2.00% as of September 30, 2017; and 3.13% as of December 31, 2016 2 Effective rates on borrowings are 3.70% as of December 31, 2017; 3.70% as of September 30, 2017; and 3.20% as of December 31, 2016 3 Interest rate of 4.06% as of December 31, 2017; 3.50% as of September 30, 2017; 3.71% as of December 31, 2016 4 Interest rate of 6.38% as of December 31, 2017, September 30, 2017 and December 31, 2016 5 Interest rate of 4.88% as of December 31, 2017 6 Fixed interest rates ranging from 2.33% to 3.25% as of December 31, 2017, September 30, 2017, and December 31, 2016 7 Fixed interest rates ranging from 2.72% to 10.39% as of December 31, 2017, September 30, 2016, and December 31, 2016
Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash from the Company’s balance sheet to the same amounts shown in the Company’s consolidated statement of cash flows for the three months ended December 31, 2017 (in thousands): December 31, 2017 Cash and cash equivalents $ 63,827 Restricted cash 1,300,000 Total cash, cash equivalents, and restricted cash $ 1,363,827

Geographic Data (Tables)

Geographic Data (Tables)	3 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Geographic Information	The following tables summarize certain geographic information for the periods presented (in thousands): Three Months Ended December 31, 2017 2016 Net sales U.S. $ 1,076,262 $ 960,235 Canada 45,717 41,949 Total net sales $ 1,121,979 $ 1,002,184 December 31, September 30, December 31, 2017 2017 2016 Long-lived assets U.S. $ 488,137 $ 507,236 $ 507,295 Canada 13,225 13,446 12,716 Total long-lived assets $ 501,362 $ 520,682 $ 520,011

Supplemental Guarantor Inform28

Supplemental Guarantor Information (Tables)	3 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Condensed Consolidated Balance Sheets	BEACON ROOFING SUPPLY, INC. Condensed Consolidating Balance Sheets (Unaudited; In thousands) December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries 1 Eliminations and Other Consolidated Assets Current assets: Cash and cash equivalents $ - $ 70,698 $ 2,122 $ (8,993 ) $ 63,827 Restricted cash - - 1,300,000 - 1,300,000 Accounts receivable, net - 526,068 27,775 (1,140 ) 552,703 Inventories, net - 581,288 22,505 - 603,793 Prepaid expenses and other current assets 17,713 194,007 6,998 - 218,718 Total current assets 17,713 1,372,061 1,359,400 (10,133 ) 2,739,041 Intercompany receivable, net - 730,364 - (730,364 ) - Investments in consolidated subsidiaries 3,239,031 - - (3,239,031 ) - Deferred income taxes, net 18,286 - - (18,286 ) - Property and equipment, net 8,271 135,925 10,491 - 154,687 Goodwill - 1,220,813 31,012 - 1,251,825 Intangibles, net - 408,123 2,734 - 410,857 Other assets, net 3,341 5,527 - - 8,868 Total Assets $ 3,286,642 $ 3,872,813 $ 1,403,637 $ (3,997,814 ) $ 4,565,278 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 21,511 $ 296,547 $ 7,517 $ (10,133 ) $ 315,442 Accrued expenses 27,467 232,131 6,451 - 266,049 Current portions of long-term debt 4,500 9,739 - - 14,239 Total current liabilities 53,478 538,417 13,968 (10,133 ) 595,730 Intercompany payable, net 680,761 - 49,603 (730,364 ) - Borrowings under revolving lines of credit, net - - - - - Long-term debt, net 700,059 - 1,300,000 - 2,000,059 Deferred income taxes, net and other - 111,066 671 (18,286 ) 93,451 Long-term obligations under equipment financing and other, net - 23,624 70 - 23,694 Total liabilities 1,434,298 673,107 1,364,312 (758,783 ) 2,712,934 Total stockholders' equity 1,852,344 3,199,706 39,325 (3,239,031 ) 1,852,344 Total Liabilities and Stockholders' Equity $ 3,286,642 $ 3,872,813 $ 1,403,637 $ (3,997,814 ) $ 4,565,278 1 Includes $1.30 billion in restricted cash and long term debt related to the Allied Acquisition temporarily held in Beacon Escrow Corporation – see Note 8 for further details. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Balance Sheets (Unaudited; In thousands) September 30, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Assets Current assets: Cash and cash equivalents $ - $ 149,799 $ 1,582 $ (13,131 ) $ 138,250 Accounts receivable, net - 663,034 42,633 (1,140 ) 704,527 Inventories, net - 527,226 24,698 - 551,924 Prepaid expenses and other current assets 4,195 198,817 6,126 - 209,138 Total current assets 4,195 1,538,876 75,039 (14,271 ) 1,603,839 Intercompany receivable, net - 655,372 - (655,372 ) - Investments in consolidated subsidiaries 3,160,273 - - (3,160,273 ) - Deferred income taxes, net 30,822 - - (30,822 ) - Property and equipment, net 6,610 138,955 10,564 - 156,129 Goodwill - 1,220,812 31,174 - 1,251,986 Intangibles, net - 426,187 2,882 - 429,069 Other assets, net 2,912 5,622 - - 8,534 Total Assets $ 3,204,812 $ 3,985,824 $ 119,659 $ (3,860,738 ) $ 3,449,557 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 27,174 $ 468,891 $ 21,903 $ (14,271 ) $ 503,697 Accrued expenses 51,183 204,173 5,941 - 261,297 Current portions of long-term obligations 4,500 9,641 - - 14,141 Total current liabilities 82,857 682,705 27,844 (14,271 ) 779,135 Intercompany payable, net 618,881 - 36,491 (655,372 ) - Borrowings under revolving lines of credit, net - - 3,205 - 3,205 Long-term debt, net 721,268 - - - 721,268 Deferred income taxes, net - 168,209 996 (30,822 ) 138,383 Long-term obligations under equipment financing and other, net - 25,694 66 - 25,760 Total liabilities 1,423,006 876,608 68,602 (700,465 ) 1,667,751 Total stockholders' equity 1,781,806 3,109,216 51,057 (3,160,273 ) 1,781,806 Total Liabilities and Stockholders' Equity $ 3,204,812 $ 3,985,824 $ 119,659 $ (3,860,738 ) $ 3,449,557 BEACON ROOFING SUPPLY, INC. Condensed Consolidating Balance Sheets (Unaudited; In thousands) December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Assets Current assets: Cash and cash equivalents $ - $ 83,617 $ 3,606 $ (13,952 ) $ 73,271 Accounts receivable, net - 467,093 24,162 (1,357 ) 489,898 Inventories, net - 503,834 24,875 - 528,709 Prepaid expenses and other current assets 2,651 199,305 7,695 - 209,651 Total current assets 2,651 1,253,849 60,338 (15,309 ) 1,301,529 Intercompany receivable, net - 900,545 - (900,545 ) - Investments in consolidated subsidiaries 2,915,905 - - (2,915,905 ) - Deferred income taxes, net 58,561 - - (58,561 ) - Property and equipment, net 5,250 132,482 9,608 - 147,340 Goodwill - 1,168,575 28,975 - 1,197,550 Intangibles, net - 441,101 3,109 - 444,210 Other assets, net 1,243 268 - - 1,511 Total Assets $ 2,983,610 $ 3,896,820 $ 102,030 $ (3,890,320 ) $ 3,092,140 Liabilities and Stockholders' Equity Current liabilities: Accounts payable $ 26,354 $ 313,647 $ 12,145 $ (15,309 ) $ 336,837 Accrued expenses 20,510 141,266 4,703 - 166,479 Current portions of long-term obligations 4,500 10,110 - - 14,610 Total current liabilities 51,364 465,023 16,848 (15,309 ) 517,926 Intercompany payable, net 859,886 - 40,659 (900,545 ) - Borrowings under revolving lines of credit - 330,444 2,235 - 332,679 Long-term debt, net 722,516 - - - 722,516 Deferred income taxes, net - 194,555 266 (58,561 ) 136,260 Long-term obligations under equipment financing and other, net - 32,869 46 - 32,915 Total liabilities 1,633,766 1,022,891 60,054 (974,415 ) 1,742,296 Total stockholders' equity 1,349,844 2,873,929 41,976 (2,915,905 ) 1,349,844 Total Liabilities and Stockholders' Equity $ 2,983,610 $ 3,896,820 $ 102,030 $ (3,890,320 ) $ 3,092,140
Condensed Consolidated Statements of Operations	BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Operations (Unaudited; In thousands, except share and per share amounts) Three Months Ended December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries 1 Eliminations and Other Consolidated Net sales $ - $ 1,076,262 $ 45,717 $ - $ 1,121,979 Cost of products sold - 816,436 35,790 - 852,226 Gross profit - 259,826 9,927 - 269,753 Operating expense 323 210,755 9,579 - 220,657 Intercompany charges (income) 893 (893 ) - - - Income (loss) from operations (1,216 ) 49,964 348 - 49,096 Interest expense, financing costs, and other 10,076 825 11,667 - 22,568 Intercompany interest expense (income) (5,708 ) 5,321 387 - - Income (loss) before provision for income taxes (5,584 ) 43,818 (11,706 ) - 26,528 Provision for (benefit from) income taxes 5,521 (46,672 ) 83 - (41,068 ) Income (loss) before equity in net income of subsidiaries (11,105 ) 90,490 (11,789 ) - 67,596 Equity in net income of subsidiaries 78,701 - - (78,701 ) - Net income (loss) $ 67,596 $ 90,490 $ (11,789 ) $ (78,701 ) $ 67,596 Weighted-average common stock outstanding: Basic 67,825,430 Diluted 69,244,678 Net income per share: Basic $ 1.00 Diluted $ 0.98 1 Includes interest expense from $1.30 billion in long term debt related to the Allied Acquisition temporarily held in Beacon Escrow Corporation – see Note 8 for further details. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Operations (Unaudited; In thousands, except share and per share amounts) Three Months Ended December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net sales $ - $ 960,235 $ 41,949 $ - $ 1,002,184 Cost of products sold - 718,534 32,583 - 751,117 Gross profit - 241,701 9,366 - 251,067 Operating expenses 8,646 187,073 8,391 - 204,110 Intercompany charges (income) (11,953 ) 11,399 554 - - Income from operations 3,307 43,229 421 - 46,957 Interest expense, financing costs, and other 15,354 (2,545 ) 765 - 13,574 Intercompany interest expense (income) (5,593 ) 5,593 - - - Income (loss) before provision for income taxes (6,454 ) 40,181 (344 ) - 33,383 Provision for (benefit from) income taxes (2,854 ) 15,902 (95 ) - 12,953 Income (loss) before equity in net income of subsidiaries (3,600 ) 24,279 (249 ) - 20,430 Equity in net income of subsidiaries 24,030 - - (24,030 ) - Net income (loss) $ 20,430 $ 24,279 $ (249 ) $ (24,030 ) $ 20,430 Weighted-average common stock outstanding: Basic 59,943,264 Diluted 60,993,080 Net income per share: Basic $ 0.34 Diluted $ 0.33
Condensed Consolidated Statements of Comprehensive Income	BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Comprehensive Income (Unaudited; In thousands) Three Months Ended December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net income (loss) $ 67,596 $ 90,490 $ (11,789 ) $ (78,701 ) $ 67,596 Other comprehensive income: Foreign currency translation adjustment 57 - 57 (57 ) 57 Total other comprehensive income 57 - 57 (57 ) 57 Comprehensive income (loss) $ 67,653 $ 90,490 $ (11,732 ) $ (78,758 ) $ 67,653 Three Months Ended December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net income (loss) $ 20,430 $ 24,279 $ (249 ) $ (24,030 ) $ 20,430 Other comprehensive loss: Foreign currency translation adjustment (1,652 ) - (1,652 ) 1,652 (1,652 ) Total other comprehensive loss (1,652 ) - (1,652 ) 1,652 (1,652 ) Comprehensive income (loss) $ 18,778 $ 24,279 $ (1,901 ) $ (22,378 ) $ 18,778
Condensed Consolidated Statements of Cash Flows	BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Cash Flows (Unaudited; In thousands) Three Months Ended December 31, 2017 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries 1 Eliminations and Other Consolidated Net cash provided by (used in) operating activities $ (37,331 ) $ 2,338 $ (9,658 ) $ 4,195 $ (40,456 ) Investing Activities Purchases of property and equipment (2,117 ) (4,874 ) (425 ) - (7,416 ) Acquisition of businesses - - - - - Proceeds from the sale of assets - 398 15 - 413 Intercompany activity 61,938 - - (61,938 ) - Net cash provided by (used in) investing activities 59,821 (4,476 ) (410 ) (61,938 ) (7,003 ) Financing Activities Borrowings under revolving lines of credit - 878 16,524 - 17,402 Repayments under revolving lines of credit - (877 ) (19,671 ) - (20,548 ) Repayments under term loan - - - - - Repayments under equipment financing facilities and other - (1,973 ) 5 - (1,968 ) Borrowings under Senior Notes - - 1,300,000 - 1,300,000 Payment of debt issuance costs (21,917 ) - - - (21,917 ) Payment of issuance costs from secondary offering of common stock (429 ) - - - (429 ) Proceeds from issuance of common stock related to equity awards 3,781 - - - 3,781 Taxes paid related to net share settlement of equity awards (3,925 ) - - - (3,925 ) Intercompany activity - (74,991 ) 13,110 61,881 - Net cash provided by (used in) financing activities (22,490 ) (76,963 ) 1,309,968 61,881 1,272,396 Effect of exchange rate changes on cash, cash equivalents, and restricted cash - - 640 - 640 Net increase (decrease) in cash, cash equivalents, and restricted cash - (79,101 ) 1,300,540 4,138 1,225,577 Cash, cash equivalents, and restricted cash, beginning of period - 149,799 1,582 (13,131 ) 138,250 Cash, cash equivalents, and restricted cash, end of period $ - $ 70,698 $ 1,302,122 $ (8,993 ) $ 1,363,827 1 Includes activity from $1.30 billion in long term debt related to the Allied Acquisition temporarily held in Beacon Escrow Corporation – see Note 8 for further details. BEACON ROOFING SUPPLY, INC. Condensed Consolidating Statements of Cash Flows (Unaudited; In thousands) Three Months Ended December 31, 2016 Parent Guarantor Subsidiaries Non- Guarantor Subsidiaries Eliminations and Other Consolidated Net cash provided by (used in) operating activities $ (18,908 ) $ 100,962 $ 1,084 $ (5,015 ) $ 78,123 Investing Activities Purchases of property and equipment (1,006 ) (6,073 ) (201 ) - (7,280 ) Acquisition of businesses (1,850 ) - - - (1,850 ) Proceeds from the sale of assets - 388 12 - 400 Intercompany activity 19,726 - - (19,726 ) - Net cash provided by (used in) investing activities 16,870 (5,685 ) (189 ) (19,726 ) (8,730 ) Financing Activities Borrowings under revolving lines of credit - 352,807 2,250 - 355,057 Repayments under revolving lines of credit - (377,896 ) (4,499 ) - (382,395 ) Repayments under term loan (1,125 ) - - - (1,125 ) Repayments under equipment financing facilities and other - (2,405 ) - - (2,405 ) Proceeds from issuance of common stock 3,460 - - - 3,460 Taxes paid related to net share settlement of equity awards (297 ) - - - (297 ) Intercompany activity - (21,613 ) 1,887 19,726 - Net cash provided by (used in) financing activities 2,038 (49,107 ) (362 ) 19,726 (27,705 ) Effect of exchange rate changes on cash, cash equivalents, and restricted cash - - 197 - 197 Net increase (decrease) in cash, cash equivalents, and restricted cash - 46,170 730 (5,015 ) 41,885 Cash, cash equivalents, and restricted cash, beginning of period - 37,447 2,876 (8,937 ) 31,386 Cash, cash equivalents, and restricted cash, end of period $ - $ 83,617 $ 3,606 $ (13,952 ) $ 73,271

Company Overview - Additional I

Company Overview - Additional Information (Detail)	3 Months Ended
	Dec. 31, 2017StateProvince
Company Overview [Line Items]
Date of incorporation	Aug. 22, 1997
United States
Company Overview [Line Items]
Number of states in which entity operates | State	48
Canada
Company Overview [Line Items]
Number of provinces in which entity operates | Province	6

Summary of Significant Accoun30

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended
	Dec. 31, 2017USD ($)
Accounting Standards Update 2016-09 [Member]
Significant Accounting Policies [Line Items]
Excess tax benefits recognized	$ 2.4

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ in Thousands	May 01, 2017USD ($)Location	Mar. 01, 2017USD ($)Location	Jan. 09, 2017USD ($)Location	Jan. 03, 2017USD ($)Location	Dec. 16, 2016USD ($)Location	Sep. 30, 2017USD ($)BranchBusiness	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)
Business Acquisition [Line Items]
Number Of Business Locations Acquired | Branch						23
Number Of Business Locations Acquired | Business						5
Business Acquisitions Purchase Price Allocation Goodwill Amount						$ 1,251,986	$ 1,251,825	$ 1,197,550	$ 1,197,565
BJ Supply Company
Business Acquisition [Line Items]
Number Of Business Locations Acquired | Location					1
Business Acquisition, sales reported by acquired entity for last annual period					$ 4,000
American Building and Roofing, Inc
Business Acquisition [Line Items]
Number Of Business Locations Acquired | Location				7
Business Acquisition, sales reported by acquired entity for last annual period				$ 36,000
Eco Insulation Supply [Member]
Business Acquisition [Line Items]
Number Of Business Locations Acquired | Location			1
Business Acquisition, sales reported by acquired entity for last annual period			$ 8,000
Acme Building Materials Inc
Business Acquisition [Line Items]
Number Of Business Locations Acquired | Location		3
Business Acquisition, sales reported by acquired entity for last annual period		$ 13,000
Lowry's Inc.
Business Acquisition [Line Items]
Number Of Business Locations Acquired | Location	11
Business Acquisition, sales reported by acquired entity for last annual period	$ 76,000
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Business Acquisitions Purchase Price Allocation Goodwill Amount							53,000
Business Acquisitions Purchase Price Allocation Intangible Assets Other Than Goodwill							$ 47,400

Net Income per Share - Calculat

Net Income per Share - Calculation of Weighted-Average Shares Outstanding (Detail) - shares	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Weighted Average Number of Shares Outstanding [Line Items]
Weighted-average common shares outstanding, basic	67,825,430	59,943,264
Effect of dilutive securities:
Weighted-average common shares outstanding, diluted	69,244,678	60,993,080
Stock Options [Member]
Effect of dilutive securities:
Weighted Average Number Diluted Shares Outstanding Adjustment	914,724	649,644
Restricted Stock [Member]
Effect of dilutive securities:
Weighted Average Number Diluted Shares Outstanding Adjustment	504,524	400,172

Net Income per Share - Schedule

Net Income per Share - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	288,275	561,741
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		247,559

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Stockholders Equity (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Balance	$ 1,781,806
Beginning Balance(in shares)	67,700,858
Issuance of common stock, net of shares withheld for taxes	$ (145)
Issuance costs related to secondary offering of common stock	(429)
Stock-based compensation	3,459
Other comprehensive income	57
Net income	67,596	$ 20,430
Balance	$ 1,852,344	$ 1,349,844
Ending Balance(in shares)	67,972,383	60,030,516
Common Stock [Member]
Class Of Stock [Line Items]
Balance	$ 677
Beginning Balance(in shares)	67,700,858
Issuance of common stock, net of shares withheld for taxes	$ 2
Issuance of common stock, net of shares withheld for taxes (in shares)	271,525
Balance	$ 679
Ending Balance(in shares)	67,972,383
Additional Paid-in Capital [Member]
Class Of Stock [Line Items]
Balance	$ 1,047,506
Issuance of common stock, net of shares withheld for taxes	(147)
Issuance costs related to secondary offering of common stock	(429)
Stock-based compensation	3,459
Balance	1,050,389
Retained Earnings [Member]
Class Of Stock [Line Items]
Balance	748,186
Net income	67,596
Balance	815,782
Accumulated Other Comprehensive Loss [Member]
Class Of Stock [Line Items]
Balance	(14,563)
Other comprehensive income	57
Balance	$ (14,506)

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - shares	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Equity [Abstract]
Common stock (voting), shares authorized	100,000,000	100,000,000	100,000,000
Undesignated Preferred Stock, shares authorized	5,000,000	5,000,000	5,000,000
Common Stock (Voting), issued	67,972,383	67,700,858	60,030,516
Common Stock (voting), outstanding	67,972,383	67,700,858	60,030,516
Undesignated Preferred Stock, outstanding	0	0	0

Stockholders' Equity - Reclassi

Stockholders' Equity - Reclassification out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,781,806
Other comprehensive income before reclassifications	57	$ (1,652)
Balance	1,852,344	$ 1,349,844
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(14,563)
Other comprehensive income before reclassifications	57
Balance	(14,506)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(14,563)
Other comprehensive income before reclassifications	57
Balance	$ (14,506)

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Feb. 09, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation number of shares authorized			5,000,000
Stock-based compensation number of shares available for awards	3,638,039
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares that will vest	100.00%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non Qualified Options Expire	10 years
Allocated Share-based Compensation Expense	$ 1.1	$ 1.3
Unrecognized compensation cost related to unvested stock	$ 8
Unrecognized compensation cost related to unvested stock, expected weighted-average period of recognition	2 years 3 months 19 days
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 2.4	$ 2.5
Unrecognized compensation cost related to unvested stock	$ 18.2
Unrecognized compensation cost related to unvested stock, expected weighted-average period of recognition	2 years 1 month 7 days
Vesting period	3 years
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares that will vest	0.00%
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares that will vest	150.00%

Stock-based Compensation - Fair

Stock-based Compensation - Fair Values of Options, Black-Scholes Option-Pricing Model, Weighted-Average Assumptions (Detail)	3 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	2.10%
Expected volatility	26.43%
Expected life (in years)	5 years 5 months 15 days
Dividend yield	0.00%

Stock-based compensation - Stoc

Stock-based compensation - Stock Options Outstanding and Activity During the Period (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017
Options Outstanding
Balance as of September 30, 2017	2,084,228
Granted	276,370
Exercised	(154,588)
Canceled/Forfeited	(7,711)
Expired	(2,274)
Balance as of December 31, 2017	2,196,025	2,084,228
Vested and expected to vest after December 31, 2017	2,168,798
Exercisable as of December 31, 2017	1,582,337
Weighted-Average Exercise Price
Beginning Balance	$ 28.84
Granted	55.17
Exercised	24.46
Canceled/Forfeited	38.05
Expired	14.56
Ending Balance	32.44	$ 28.84
Vested and expected to vest after December 31, 2017	32.25
Exercisable as of December 31, 2017	$ 27.40
Weighted-Average Remaining Contractual Life
Balance	6 years 4 months 24 days	6 years 1 month 6 days
Vested and expected to vest after December 31, 2017	6 years 4 months 24 days
Exercisable as of December 31, 2017	5 years 4 months 24 days
Aggregate Intrinsic Value
Balance	$ 68,776	$ 46,714
Vested and expected to vest after December 31, 2017	68,339
Exercisable as of December 31, 2017	$ 57,537

Stock-based compensation - St40

Stock-based compensation - Stock Option Grants, Vesting, and Exercises (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted-average fair value of stock options granted	$ 15.86	$ 14.21
Total fair value of stock options vested	$ 3,773	$ 4,887
Total intrinsic value of stock options exercised	$ 5,448	$ 2,750

Stock-based Compensation - Rest

Stock-based Compensation - Restricted Shares and Units Outstanding and Activity During the Period (Detail) - $ / shares	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Weighted - Average Grant Date Fair Value
Granted	$ 55.17	$ 47.40
Restricted Stock Units (RSUs) [Member]
Outstanding
Balance at September 30, 2017	770,973
Granted	160,510
Performance awards	41,440
Released	(184,771)
Canceled/Forfeited	(7,206)
Balance at December 31, 2017	780,946
Vested and expected to vest after December 31, 2017	748,271
Weighted - Average Grant Date Fair Value
Balance at September 30, 2017	$ 38.95
Granted	55.17
Performance awards	39.56
Released	31.31
Canceled/Forfeited	40.65
Balance at December 31, 2017	44.11
Vested and expected to vest after December 31, 2017	$ 43.92

Stock-based Compensation - Sche

Stock-based Compensation - Schedule Of Restricted Stock Units Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted-average fair value of RSUs granted	$ 55.17	$ 47.40
Total fair value of RSUs vested	$ 5,786	$ 1,002
Total intrinsic value of RSUs released	$ 10,683	$ 1,096

Goodwill and Intangibles - Summ

Goodwill and Intangibles - Summary of Changes in goodwill (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 1,251,986	$ 1,197,565
Acquisitions		774
Translation and other adjustments	(161)	(789)
Ending balance	$ 1,251,825	$ 1,197,550

Goodwill and Intangible - Addit

Goodwill and Intangible - Additional Information (Details) (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Goodwill And Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired			$ 47.4
Amortization of Intangible Assets	$ 18.2	$ 20.1
Minimum [Member]
Goodwill And Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Maximum [Member]
Goodwill And Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years
Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years 1 month 7 days
Customer Relationships [Member]
Goodwill And Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired			42.7
Customer Relationships [Member] | Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years 4 months 9 days
Trademarks [Member]
Goodwill And Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired			4.6
Trademarks [Member] | Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years 2 months 1 day
Beneficial Lease Arrangements [Member]
Goodwill And Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired			$ 0.1
Beneficial Lease Arrangements [Member] | Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years 7 months 24 days

Goodwill and Intangible - Intan

Goodwill and Intangible - Intangibles and Other Assets, Included in Other Long-term Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets	$ 624,368	$ 624,410	$ 576,841
Less: Accumulated amortization	(286,561)	(268,391)	(205,681)
Total amortizable intangible assets, net	337,807	356,019	371,160
Indefinite lived trademarks	73,050	73,050	73,050
Total intangibles, net	$ 410,857	429,069	444,210
Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years 1 month 7 days
Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	20 years
Noncompete Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets	$ 2,824	2,824	2,824
Noncompete Agreements [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	3 years 1 month 6 days
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets	$ 609,984	610,026	567,157
Customer Relationships [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years 4 months 9 days
Trademarks [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets	$ 10,500	10,500	5,900
Trademarks [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years 2 months 1 day
Beneficial Lease Arrangements [Member]
Finite Lived Intangible Assets [Line Items]
Amortizable intangible assets	$ 1,060	$ 1,060	$ 960
Beneficial Lease Arrangements [Member] | Weighted Average [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	8 years 7 months 24 days

Goodwill and Intangible - Estim

Goodwill and Intangible - Estimated Future Annual Amortization (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
2018 (Jan - Sept)	$ 53,374
2,019	58,774
2,020	47,754
2,021	38,234
2,022	30,289
Thereafter	109,382
Total amortizable intangible assets, net	$ 337,807	$ 356,019	$ 371,160

Financing Arrangements - Long-t

Financing Arrangements - Long-term Debt Instruments (Detail) - USD ($) $ in Thousands		Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total long-term borrowings under Senior Secured Credit Facility		$ 0	$ 3,205	$ 332,679
Total long-term obligations under equipment financing facilities and other		23,694	25,760	32,915
Senior Notes, Matures October 2023 [Member]
Debt Instrument [Line Items]
Senior Notes	[1]	292,648	292,328	291,369
Senior Notes, Matures November 2025 [Member]
Debt Instrument [Line Items]
Senior Notes	[2]	1,278,083
Senior Notes [Member]
Debt Instrument [Line Items]
Less: current portion		0	0	0
Total long-term borrowings under Senior Notes		1,570,731	292,328	291,369
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Capital lease obligations, various maturities through November 2021	[3]	19,033	19,956	23,837
Equipment Financing Facilities [Member]
Debt Instrument [Line Items]
Equipment financing facilities, various maturities through September 2021	[4]	14,400	15,445	19,188
Senior Secured Credit Facility
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility		433,828	436,645	768,326
Less: current portion		(4,500)	(4,500)	(4,500)
Total long-term borrowings under Senior Secured Credit Facility		429,328	432,145	763,826
Senior Secured Credit Facility | Term Loan [Member]
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	[5]	433,828	433,440	435,647
Senior Secured Credit Facility | U.S. [Member]
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	[6]			330,445
Senior Secured Credit Facility | Canada [Member]
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	[7]		3,205	2,234
Equipment Financing Facilities and Other [Member]
Debt Instrument [Line Items]
Total obligations under equipment financing facilities and other		33,433	35,401	43,025
Less: current portion		(9,739)	(9,641)	(10,110)
Total long-term obligations under equipment financing facilities and other		$ 23,694	$ 25,760	$ 32,915
[1]	Interest rate of 6.38% as of December 31, 2017, September 30, 2017 and December 31, 2016
[2]	Interest rate of 4.88% as of December 31, 2017
[3]	Fixed interest rates ranging from 2.72% to 10.39% as of December 31, 2017, September 30, 2016, and December 31, 2016
[4]	Fixed interest rates ranging from 2.33% to 3.25% as of December 31, 2017, September 30, 2017, and December 31, 2016
[5]	Interest rate of 4.06% as of December 31, 2017; 3.50% as of September 30, 2017; 3.71% as of December 31, 2016
[6]	Effective rates on borrowings are 1.50% as of December 31, 2017; 2.00% as of September 30, 2017; and 3.13% as of December 31, 2016
[7]	Effective rates on borrowings are 3.70% as of December 31, 2017; 3.70% as of September 30, 2017; and 3.20% as of December 31, 2016

Financing Arrangements - Long48

Financing Arrangements - Long-term Debt Instruments (Parenthetical) (Detail)	Oct. 02, 2015	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017	Sep. 30, 2016
Equipment Financing Facilities [Member]
Debt Instrument [Line Items]
Debt instrument maturity date		Sep. 30, 2021
Equipment Financing Facilities [Member] | Minimum [Member]
Debt Instrument [Line Items]
Equipment financing facilities, fixed interest rate percentage		2.33%	2.33%	2.33%
Equipment Financing Facilities [Member] | Maximum [Member]
Debt Instrument [Line Items]
Equipment financing facilities, fixed interest rate percentage		3.25%	3.25%	3.25%
Senior Secured Credit Facility | Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End		4.06%	3.71%	3.50%
Line of Credit Facility, Expiration Date		Oct. 1, 2022
Senior Secured Credit Facility | U.S. [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End		1.50%	3.13%	2.00%
Line of Credit Facility, Expiration Date		Oct. 1, 2020
Senior Secured Credit Facility | Canada [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate at Period End		3.70%	3.20%	3.70%
Line of Credit Facility, Expiration Date		Oct. 1, 2020
Senior Notes, Matures October 2023 [Member]
Debt Instrument [Line Items]
Senior Notes, Interest Rate at Period End		6.38%	6.38%	6.38%
Debt instrument maturity date	Oct. 1, 2023	Oct. 1, 2023
Senior Notes, Matures November 2025 [Member]
Debt Instrument [Line Items]
Senior Notes, Interest Rate at Period End		4.88%
Debt instrument maturity date		Nov. 1, 2025
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt instrument maturity date		Nov. 30, 2021
Capital Lease Obligations [Member] | Minimum [Member]
Debt Instrument [Line Items]
Capital lease obligations, fixed interest rate percentage		2.72%	2.72%		2.72%
Capital Lease Obligations [Member] | Maximum [Member]
Debt Instrument [Line Items]
Capital lease obligations, fixed interest rate percentage		10.39%	10.39%		10.39%

Financing Arrangements - Additi

Financing Arrangements - Additional Information (Detail)		Oct. 25, 2017USD ($)	Sep. 16, 2016USD ($)	Oct. 02, 2015USD ($)	Dec. 31, 2017USD ($)Covenant	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Dec. 03, 2017USD ($)	Sep. 30, 2017USD ($)
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,450,000,000
Borrowings under Senior Notes	[1]				$ 1,300,000,000	$ 0
Maximum percentage of borrowing availability to in effect covenant applicability					10.00%
Amortization of Debt Issuance Costs			$ 1,600,000
LIBOR floor rate			0.25%
LIBOR spread rate			0.25%
ABL Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				Oct. 1, 2020
Line of Credit Facility, Maximum Borrowing Capacity				$ 700,000,000
Proceeds from Lines of Credit				350,000,000
Debt Instrument, Weighted average interest rate					1.50%
Line of credit facility, unused fees					0.25%
Number of financial covenants | Covenant					1
Fixed charge coverage ratio					100.00%
Debt Instrument, Covenant Description					The covenant is only applicable when the borrowing availability is less than 10% of the maximum loan cap or $60.0 million.
Maximum borrowing availability for covenant applicability					$ 60,000,000
ABL Facility [Member] | Other Assets, Net [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs					$ 4,900,000
ABL Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate spread					4.75%
ABL Facility [Member] | Tranche One [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate spread					1.25%
ABL Facility [Member] | Tranche Two [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate spread					1.50%
ABL Facility [Member] | Tranche Three [Member]
Debt Instrument [Line Items]
Debt Instrument, interest rate spread					1.75%
ABL Facility [Member] | U.S. [Member]
Debt Instrument [Line Items]
Long-term Line of Credit				670,000,000
Standby letters of credit outstanding					$ 10,700,000
ABL Facility [Member] | Canada [Member]
Debt Instrument [Line Items]
Long-term Line of Credit				$ 30,000,000
Senior Notes, Matures November 2025 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate					4.88%
Debt instrument maturity date					Nov. 1, 2025
Senior Notes Payable	[2]				$ 1,278,083,000
Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument maturity date				Oct. 1, 2022
Long-term Line of Credit				$ 450,000,000				$ 433,800,000
Debt Instrument, Frequency of Periodic Payment					quarterly
Debt Instrument, Periodic Payment				$ 1,100,000
Debt Instrument, Description Of Change In Interest Rate					lowering the LIBOR floor by 25 basis points and lowering the spread by 25 basis points
Senior Notes, Matures October 2023 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate					6.38%	6.38%			6.38%
Debt instrument maturity date				Oct. 1, 2023	Oct. 1, 2023
Senior Notes Payable	[3]				$ 292,648,000	$ 291,369,000			$ 292,328,000
Borrowings under Senior Notes				$ 300,000,000
Debt instrument, coupon rate				6.38%
Unsecured Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument maturity year					2,020
Equipment Financing Facilities [Member]
Debt Instrument [Line Items]
Equipment financing facilities, various maturities through September 2021					$ 14,400,000
Equipment Financing Facilities and Other [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of Fixed Interest Rate of Equipment Financing Facilities					2.33%
Equipment Financing Facilities and Other [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of Fixed Interest Rate of Equipment Financing Facilities					3.25%
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Debt instrument maturity date					Nov. 30, 2021
Capital lease obligations, various maturities through November 2021	[4]				$ 19,033,000	$ 23,837,000			$ 19,956,000
Capital Lease Obligations [Member] | Minimum [Member]
Debt Instrument [Line Items]
Capital Leases of Lessor, Contingent Rentals, Basis Spread on Variable Rate					2.72%	2.72%	2.72%
Capital Lease Obligations [Member] | Maximum [Member]
Debt Instrument [Line Items]
Capital Leases of Lessor, Contingent Rentals, Basis Spread on Variable Rate					10.39%	10.39%	10.39%
Allied Acquisition [Member]
Debt Instrument [Line Items]
Borrowings under Senior Notes					$ 1,300,000,000
Allied Acquisition [Member] | Senior Notes, Matures November 2025 [Member]
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount		$ 1,300,000,000
Debt instrument interest rate		4.875%
Debt instrument, issue price percentage		100.00%
Debt instrument maturity date		Nov. 1, 2025
Roofing Supply Group [Member]
Debt Instrument [Line Items]
Payments of Financing Costs, Total							$ 31,300,000
[1]	Gross funds from issuance of 2025 Senior Notes to finance the Company’s Allied Acquisition, presented as restricted cash on the Company’s consolidated balance sheet – see Note 8
[2]	Interest rate of 4.88% as of December 31, 2017
[3]	Interest rate of 6.38% as of December 31, 2017, September 30, 2017 and December 31, 2016
[4]	Fixed interest rates ranging from 2.72% to 10.39% as of December 31, 2017, September 30, 2016, and December 31, 2016

Financing Arrangements - Summar

Financing Arrangements - Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Debt Disclosure [Abstract]
Cash and cash equivalents	$ 63,827	$ 138,250	$ 73,271
Restricted cash	1,300,000
Total cash, cash equivalents, and restricted cash	$ 1,363,827	$ 138,250	$ 73,271	$ 31,386

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Commitments And Contingencies Disclosure [Abstract]
Operating Leases, Rent Expense, Net, Total	$ 15.2	$ 14.2

Geographic Data - Schedule Of G

Geographic Data - Schedule Of Geographic Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Segment Reporting Information [Line Items]
Net sales	$ 1,121,979	$ 1,002,184
Long-lived assets	501,362	520,011	$ 520,682
U.S. [Member]
Segment Reporting Information [Line Items]
Net sales	1,076,262	960,235
Long-lived assets	488,137	507,295	507,236
Canada [Member]
Segment Reporting Information [Line Items]
Net sales	45,717	41,949
Long-lived assets	$ 13,225	$ 12,716	$ 13,446

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - Fair Value, Inputs, Level 2 [Member] $ in Millions	3 Months Ended
	Dec. 31, 2017USD ($)
Senior Notes Due in 2023 [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Debt instrument maturity year	2,023
Senior Notes Due in 2023 [Member] | Carrying Value [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Senior notes	$ 300
Senior Notes Due in 2023 [Member] | Fair Value [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Senior notes	$ 320
Senior Notes Due in 2025 [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Debt instrument maturity year	2,025
Senior Notes Due in 2025 [Member] | Carrying Value [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Senior notes	$ 1,300
Senior Notes Due in 2025 [Member] | Fair Value [Member]
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Senior notes	$ 1,310

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	Dec. 22, 2017	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018
Federal corporate income tax rate	21.00%
Provisional decrease of deferred tax liabilities related to remeasurement		$ 47.4
Provisional expense for one-time transition tax liability		$ 0.9
Scenario, Forecast [Member]
Blended federal corporate income tax rate				24.50%
Federal corporate income tax rate			21.00%

Supplemental Guarantor Inform55

Supplemental Guarantor Information - Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Current assets:
Cash and cash equivalents	$ 63,827	$ 138,250	$ 73,271
Restricted cash	1,300,000
Accounts receivable, net	552,703	704,527	489,898
Inventories, net	603,793	551,924	528,709
Prepaid expenses and other current assets	218,718	209,138	209,651
Total current assets	2,739,041	1,603,839	1,301,529
Intercompany receivable, net	0	0	0
Investments in consolidated subsidiaries	0	0	0
Deferred income taxes, net	0	0	0
Property and equipment, net	154,687	156,129	147,340
Goodwill	1,251,825	1,251,986	1,197,550	$ 1,197,565
Intangibles, net	410,857	429,069	444,210
Other assets, net	8,868	8,534	1,511
Total Assets	4,565,278	3,449,557	3,092,140
Current liabilities:
Accounts payable	315,442	503,697	336,837
Accrued expenses	266,049	261,297	166,479
Current portions of long-term debt	14,239	14,141	14,610
Total current liabilities	595,730	779,135	517,926
Intercompany payable, net	0	0	0
Borrowings under revolving lines of credit, net	0	3,205	332,679
Long-term debt, net	2,000,059	721,268	722,516
Deferred income taxes, net and other	93,451	138,383	136,260
Long-term obligations under equipment financing and other, net	23,694	25,760	32,915
Total liabilities	2,712,934	1,667,751	1,742,296
Total stockholders' equity	1,852,344	1,781,806	1,349,844
Total Liabilities and Stockholders' Equity	4,565,278	3,449,557	3,092,140
Parent Company [Member]
Current assets:
Cash and cash equivalents	0	0	0
Restricted cash	0
Accounts receivable, net	0	0	0
Inventories, net	0	0	0
Prepaid expenses and other current assets	17,713	4,195	2,651
Total current assets	17,713	4,195	2,651
Intercompany receivable, net	0	0	0
Investments in consolidated subsidiaries	3,239,031	3,160,273	2,915,905
Deferred income taxes, net	18,286	30,822	58,561
Property and equipment, net	8,271	6,610	5,250
Goodwill	0	0	0
Intangibles, net	0	0	0
Other assets, net	3,341	2,912	1,243
Total Assets	3,286,642	3,204,812	2,983,610
Current liabilities:
Accounts payable	21,511	27,174	26,354
Accrued expenses	27,467	51,183	20,510
Current portions of long-term debt	4,500	4,500	4,500
Total current liabilities	53,478	82,857	51,364
Intercompany payable, net	680,761	618,881	859,886
Borrowings under revolving lines of credit, net	0	0	0
Long-term debt, net	700,059	721,268	722,516
Deferred income taxes, net and other	0	0	0
Long-term obligations under equipment financing and other, net	0	0	0
Total liabilities	1,434,298	1,423,006	1,633,766
Total stockholders' equity	1,852,344	1,781,806	1,349,844
Total Liabilities and Stockholders' Equity	3,286,642	3,204,812	2,983,610
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	70,698	149,799	83,617
Restricted cash	0
Accounts receivable, net	526,068	663,034	467,093
Inventories, net	581,288	527,226	503,834
Prepaid expenses and other current assets	194,007	198,817	199,305
Total current assets	1,372,061	1,538,876	1,253,849
Intercompany receivable, net	730,364	655,372	900,545
Investments in consolidated subsidiaries	0	0	0
Deferred income taxes, net	0	0	0
Property and equipment, net	135,925	138,955	132,482
Goodwill	1,220,813	1,220,812	1,168,575
Intangibles, net	408,123	426,187	441,101
Other assets, net	5,527	5,622	268
Total Assets	3,872,813	3,985,824	3,896,820
Current liabilities:
Accounts payable	296,547	468,891	313,647
Accrued expenses	232,131	204,173	141,266
Current portions of long-term debt	9,739	9,641	10,110
Total current liabilities	538,417	682,705	465,023
Intercompany payable, net	0	0	0
Borrowings under revolving lines of credit, net	0	0	330,444
Long-term debt, net	0	0	0
Deferred income taxes, net and other	111,066	168,209	194,555
Long-term obligations under equipment financing and other, net	23,624	25,694	32,869
Total liabilities	673,107	876,608	1,022,891
Total stockholders' equity	3,199,706	3,109,216	2,873,929
Total Liabilities and Stockholders' Equity	3,872,813	3,985,824	3,896,820
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	2,122	1,582	3,606
Restricted cash	1,300,000
Accounts receivable, net	27,775	42,633	24,162
Inventories, net	22,505	24,698	24,875
Prepaid expenses and other current assets	6,998	6,126	7,695
Total current assets	1,359,400	75,039	60,338
Intercompany receivable, net	0	0	0
Investments in consolidated subsidiaries	0	0	0
Deferred income taxes, net	0	0	0
Property and equipment, net	10,491	10,564	9,608
Goodwill	31,012	31,174	28,975
Intangibles, net	2,734	2,882	3,109
Other assets, net	0	0	0
Total Assets	1,403,637	119,659	102,030
Current liabilities:
Accounts payable	7,517	21,903	12,145
Accrued expenses	6,451	5,941	4,703
Current portions of long-term debt	0	0	0
Total current liabilities	13,968	27,844	16,848
Intercompany payable, net	49,603	36,491	40,659
Borrowings under revolving lines of credit, net	0	3,205	2,235
Long-term debt, net	1,300,000	0	0
Deferred income taxes, net and other	671	996	266
Long-term obligations under equipment financing and other, net	70	66	46
Total liabilities	1,364,312	68,602	60,054
Total stockholders' equity	39,325	51,057	41,976
Total Liabilities and Stockholders' Equity	1,403,637	119,659	102,030
Eliminations and Other [Member]
Current assets:
Cash and cash equivalents	(8,993)	(13,131)	(13,952)
Restricted cash	0
Accounts receivable, net	(1,140)	(1,140)	(1,357)
Inventories, net	0	0	0
Prepaid expenses and other current assets	0	0	0
Total current assets	(10,133)	(14,271)	(15,309)
Intercompany receivable, net	(730,364)	(655,372)	(900,545)
Investments in consolidated subsidiaries	(3,239,031)	(3,160,273)	(2,915,905)
Deferred income taxes, net	(18,286)	(30,822)	(58,561)
Property and equipment, net	0	0	0
Goodwill	0	0	0
Intangibles, net	0	0	0
Other assets, net	0	0	0
Total Assets	(3,997,814)	(3,860,738)	(3,890,320)
Current liabilities:
Accounts payable	(10,133)	(14,271)	(15,309)
Accrued expenses	0	0	0
Current portions of long-term debt	0	0	0
Total current liabilities	(10,133)	(14,271)	(15,309)
Intercompany payable, net	(730,364)	(655,372)	(900,545)
Borrowings under revolving lines of credit, net	0	0	0
Long-term debt, net	0	0	0
Deferred income taxes, net and other	(18,286)	(30,822)	(58,561)
Long-term obligations under equipment financing and other, net	0	0	0
Total liabilities	(758,783)	(700,465)	(974,415)
Total stockholders' equity	(3,239,031)	(3,160,273)	(2,915,905)
Total Liabilities and Stockholders' Equity	$ (3,997,814)	$ (3,860,738)	$ (3,890,320)

Supplemental Guarantor Inform56

Supplemental Guarantor Information - Condensed Consolidated Balance Sheets (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Restricted cash	$ 1,300,000
Long-term debt, net	2,000,059	$ 721,268	$ 722,516
Allied Acquisition [Member]
Restricted cash	1,300,000
Long-term debt, net	$ 1,300,000

Supplemental Guarantor Inform57

Supplemental Guarantor Information - Condensed Consolidated Statements of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Net sales	$ 1,121,979	$ 1,002,184
Cost of products sold	852,226	751,117
Gross profit	269,753	251,067
Operating expense	220,657	204,110
Intercompany charges (income)	0	0
Income from operations	49,096	46,957
Interest expense, financing costs, and other	22,568	13,574
Intercompany interest expense (income)	0	0
Income before provision for income taxes	26,528	33,383
Provision for (benefit from) income taxes	(41,068)	12,953
Income (loss) before equity in net income of subsidiaries	67,596	20,430
Equity in net income of subsidiaries	0	0
Net income	$ 67,596	$ 20,430
Weighted-average common stock outstanding:
Basic	67,825,430	59,943,264
Diluted	69,244,678	60,993,080
Net income per share:
Basic	$ 1	$ 0.34
Diluted	$ 0.98	$ 0.33
Parent Company [Member]
Net sales	$ 0	$ 0
Cost of products sold	0	0
Gross profit	0	0
Operating expense	323	8,646
Intercompany charges (income)	893	(11,953)
Income from operations	(1,216)	3,307
Interest expense, financing costs, and other	10,076	15,354
Intercompany interest expense (income)	(5,708)	(5,593)
Income before provision for income taxes	(5,584)	(6,454)
Provision for (benefit from) income taxes	5,521	(2,854)
Income (loss) before equity in net income of subsidiaries	(11,105)	(3,600)
Equity in net income of subsidiaries	78,701	24,030
Net income	$ 67,596	$ 20,430
Weighted-average common stock outstanding:
Basic	0	0
Diluted	0	0
Net income per share:
Basic	$ 0	$ 0
Diluted	$ 0	$ 0
Guarantor Subsidiaries [Member]
Net sales	$ 1,076,262	$ 960,235
Cost of products sold	816,436	718,534
Gross profit	259,826	241,701
Operating expense	210,755	187,073
Intercompany charges (income)	(893)	11,399
Income from operations	49,964	43,229
Interest expense, financing costs, and other	825	(2,545)
Intercompany interest expense (income)	5,321	5,593
Income before provision for income taxes	43,818	40,181
Provision for (benefit from) income taxes	(46,672)	15,902
Income (loss) before equity in net income of subsidiaries	90,490	24,279
Equity in net income of subsidiaries	0	0
Net income	$ 90,490	$ 24,279
Weighted-average common stock outstanding:
Basic	0	0
Diluted	0	0
Net income per share:
Basic	$ 0	$ 0
Diluted	$ 0	$ 0
Non-Guarantor Subsidiaries [Member]
Net sales	$ 45,717	$ 41,949
Cost of products sold	35,790	32,583
Gross profit	9,927	9,366
Operating expense	9,579	8,391
Intercompany charges (income)	0	554
Income from operations	348	421
Interest expense, financing costs, and other	11,667	765
Intercompany interest expense (income)	387	0
Income before provision for income taxes	(11,706)	(344)
Provision for (benefit from) income taxes	83	(95)
Income (loss) before equity in net income of subsidiaries	(11,789)	(249)
Equity in net income of subsidiaries	0	0
Net income	$ (11,789)	$ (249)
Weighted-average common stock outstanding:
Basic	0	0
Diluted	0	0
Net income per share:
Basic	$ 0	$ 0
Diluted	$ 0	$ 0
Eliminations and Other [Member]
Net sales	$ 0	$ 0
Cost of products sold	0	0
Gross profit	0	0
Operating expense	0	0
Intercompany charges (income)	0	0
Income from operations	0	0
Interest expense, financing costs, and other	0	0
Intercompany interest expense (income)	0	0
Income before provision for income taxes	0	0
Provision for (benefit from) income taxes	0	0
Income (loss) before equity in net income of subsidiaries	0	0
Equity in net income of subsidiaries	(78,701)	(24,030)
Net income	$ (78,701)	$ (24,030)
Weighted-average common stock outstanding:
Basic	0	0
Diluted	0	0
Net income per share:
Basic	$ 0	$ 0
Diluted	$ 0	$ 0

Supplemental Guarantor Inform58

Supplemental Guarantor Information - Condensed Consolidated Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Long-term debt, net	$ 2,000,059	$ 721,268	$ 722,516
Allied Acquisition [Member]
Long-term debt, net	$ 1,300,000

Supplemental Guarantor Inform59

Supplemental Guarantor Information - Condensed Consolidated Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Net income	$ 67,596	$ 20,430
Other comprehensive income (loss):
Foreign currency translation adjustment	57	(1,652)
Total other comprehensive income (loss)	57	(1,652)
Comprehensive income	67,653	18,778
Parent Company [Member]
Net income	67,596	20,430
Other comprehensive income (loss):
Foreign currency translation adjustment	57	(1,652)
Total other comprehensive income (loss)	57	(1,652)
Comprehensive income	67,653	18,778
Guarantor Subsidiaries [Member]
Net income	90,490	24,279
Other comprehensive income (loss):
Foreign currency translation adjustment	0	0
Total other comprehensive income (loss)	0	0
Comprehensive income	90,490	24,279
Non-Guarantor Subsidiaries [Member]
Net income	(11,789)	(249)
Other comprehensive income (loss):
Foreign currency translation adjustment	57	(1,652)
Total other comprehensive income (loss)	57	(1,652)
Comprehensive income	(11,732)	(1,901)
Eliminations and Other [Member]
Net income	(78,701)	(24,030)
Other comprehensive income (loss):
Foreign currency translation adjustment	(57)	1,652
Total other comprehensive income (loss)	(57)	1,652
Comprehensive income	$ (78,758)	$ (22,378)

Supplemental Guarantor Inform60

Supplemental Guarantor Information - Condensed Consolidated Statements of Cash Flows (Detail) - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Net cash provided by (used in) operating activities		$ (40,456)	$ 78,123
Investing Activities
Purchases of property and equipment		(7,416)	(7,280)
Acquisition of businesses		0	(1,850)
Proceeds from the sale of assets		413	400
Intercompany activity		0	0
Net cash used in investing activities		(7,003)	(8,730)
Financing Activities
Borrowings under revolving lines of credit		17,402	355,057
Repayments under revolving lines of credit		(20,548)	(382,395)
Repayments under term loan		0	(1,125)
Repayments under equipment financing facilities and other		(1,968)	(2,405)
Borrowings under Senior Notes	[1]	1,300,000	0
Payment of debt issuance costs		(21,917)	0
Payment of issuance costs from secondary offering of common stock		(429)	0
Proceeds from issuance of common stock related to equity awards		3,781	3,460
Taxes paid related to net share settlement of equity awards		(3,925)	(297)
Intercompany activity		0	0
Net cash provided by (used in) financing activities		1,272,396	(27,705)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		640	197
Net increase in cash, cash equivalents, and restricted cash		1,225,577	41,885
Cash, cash equivalents, and restricted cash, beginning of period		138,250	31,386
Cash, cash equivalents, and restricted cash, end of period		1,363,827	73,271
Parent Company [Member]
Net cash provided by (used in) operating activities		(37,331)	(18,908)
Investing Activities
Purchases of property and equipment		(2,117)	(1,006)
Acquisition of businesses		0	(1,850)
Proceeds from the sale of assets		0	0
Intercompany activity		61,938	19,726
Net cash used in investing activities		59,821	16,870
Financing Activities
Borrowings under revolving lines of credit		0	0
Repayments under revolving lines of credit		0	0
Repayments under term loan		0	(1,125)
Repayments under equipment financing facilities and other		0	0
Borrowings under Senior Notes		0
Payment of debt issuance costs		(21,917)
Payment of issuance costs from secondary offering of common stock		(429)
Proceeds from issuance of common stock related to equity awards		3,781	3,460
Taxes paid related to net share settlement of equity awards		(3,925)	(297)
Intercompany activity		0	0
Net cash provided by (used in) financing activities		(22,490)	2,038
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		0	0
Net increase in cash, cash equivalents, and restricted cash		0	0
Cash, cash equivalents, and restricted cash, beginning of period		0	0
Cash, cash equivalents, and restricted cash, end of period		0	0
Guarantor Subsidiaries [Member]
Net cash provided by (used in) operating activities		2,338	100,962
Investing Activities
Purchases of property and equipment		(4,874)	(6,073)
Acquisition of businesses		0	0
Proceeds from the sale of assets		398	388
Intercompany activity		0	0
Net cash used in investing activities		(4,476)	(5,685)
Financing Activities
Borrowings under revolving lines of credit		878	352,807
Repayments under revolving lines of credit		(877)	(377,896)
Repayments under term loan		0	0
Repayments under equipment financing facilities and other		(1,973)	(2,405)
Borrowings under Senior Notes		0
Payment of debt issuance costs		0
Payment of issuance costs from secondary offering of common stock		0
Proceeds from issuance of common stock related to equity awards		0	0
Taxes paid related to net share settlement of equity awards		0	0
Intercompany activity		(74,991)	(21,613)
Net cash provided by (used in) financing activities		(76,963)	(49,107)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		0	0
Net increase in cash, cash equivalents, and restricted cash		(79,101)	46,170
Cash, cash equivalents, and restricted cash, beginning of period		149,799	37,447
Cash, cash equivalents, and restricted cash, end of period		70,698	83,617
Non-Guarantor Subsidiaries [Member]
Net cash provided by (used in) operating activities		(9,658)	1,084
Investing Activities
Purchases of property and equipment		(425)	(201)
Acquisition of businesses		0	0
Proceeds from the sale of assets		15	12
Intercompany activity		0	0
Net cash used in investing activities		(410)	(189)
Financing Activities
Borrowings under revolving lines of credit		16,524	2,250
Repayments under revolving lines of credit		(19,671)	(4,499)
Repayments under term loan		0	0
Repayments under equipment financing facilities and other		5	0
Borrowings under Senior Notes		1,300,000
Payment of debt issuance costs		0
Payment of issuance costs from secondary offering of common stock		0
Proceeds from issuance of common stock related to equity awards		0	0
Taxes paid related to net share settlement of equity awards		0	0
Intercompany activity		13,110	1,887
Net cash provided by (used in) financing activities		1,309,968	(362)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		640	197
Net increase in cash, cash equivalents, and restricted cash		1,300,540	730
Cash, cash equivalents, and restricted cash, beginning of period		1,582	2,876
Cash, cash equivalents, and restricted cash, end of period		1,302,122	3,606
Eliminations and Other [Member]
Net cash provided by (used in) operating activities		4,195	(5,015)
Investing Activities
Purchases of property and equipment		0	0
Acquisition of businesses		0	0
Proceeds from the sale of assets		0	0
Intercompany activity		(61,938)	(19,726)
Net cash used in investing activities		(61,938)	(19,726)
Financing Activities
Borrowings under revolving lines of credit		0	0
Repayments under revolving lines of credit		0	0
Repayments under term loan		0	0
Repayments under equipment financing facilities and other		0	0
Borrowings under Senior Notes		0
Payment of debt issuance costs		0
Payment of issuance costs from secondary offering of common stock		0
Proceeds from issuance of common stock related to equity awards		0	0
Taxes paid related to net share settlement of equity awards		0	0
Intercompany activity		61,881	19,726
Net cash provided by (used in) financing activities		61,881	19,726
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		0	0
Net increase in cash, cash equivalents, and restricted cash		4,138	(5,015)
Cash, cash equivalents, and restricted cash, beginning of period		(13,131)	(8,937)
Cash, cash equivalents, and restricted cash, end of period		$ (8,993)	$ (13,952)
[1]	Gross funds from issuance of 2025 Senior Notes to finance the Company’s Allied Acquisition, presented as restricted cash on the Company’s consolidated balance sheet – see Note 8

Supplemental Guarantor Inform61

Supplemental Guarantor Information - Condensed Consolidated Statements of Cash Flows (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Long term debt	[1]	$ 1,300,000	$ 0
Allied Acquisition [Member]
Long term debt		$ 1,300,000
[1]	Gross funds from issuance of 2025 Senior Notes to finance the Company’s Allied Acquisition, presented as restricted cash on the Company’s consolidated balance sheet – see Note 8

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - USD ($)	Jan. 02, 2017	Dec. 31, 2017	Oct. 25, 2017	Sep. 30, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Preferred stock, issuance		0		0	0
Senior-secured Asset-based Revolving Line Of Credit [Member]
Subsequent Event [Line Items]
Long-term Line of Credit		$ 433,828,000		$ 436,645,000	$ 768,326,000
Allied Acquisition [Member] | Investment Agreement [Member] | Series A Cumulative Convertible Participating Preferred Stock [Member]
Subsequent Event [Line Items]
Preferred stock, issuance	400,000
Preferred stock, par value	$ 0.01
Preferred stock, liquidation preference value	$ 400,000,000
Preferred stock, liquidation purchase price per share	$ 1,000
Proceeds from convertible preferred stock	$ 400,000,000
Preferred stock initial conversion price per share	$ 41.26
Preferred stock dividend rate	6.00%
Allied Acquisition [Member] | Senior Notes, Matures November 2025 [Member]
Subsequent Event [Line Items]
Debt instrument, aggregate principal amount			$ 1,300,000,000
Allied Acquisition [Member] | Secured Term Loan B Facility [Member]
Subsequent Event [Line Items]
Long-term Line of Credit	$ 970,000,000
Allied Acquisition [Member] | Secured Term Loan B Facility [Member] | LIBOR [Member]
Subsequent Event [Line Items]
Base borrowing rates	1.25%
Allied Acquisition [Member] | Senior-secured Asset-based Revolving Line Of Credit [Member] | LIBOR [Member]
Subsequent Event [Line Items]
Base borrowing rates	2.25%
Allied Acquisition [Member] | Stock Purchase Agreement [Member]
Subsequent Event [Line Items]
Acquisition purchase price in cash	$ 2,625,000,000