GMS (GMS) 10-K 25 Jun 20 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2020	May 31, 2020	Oct. 31, 2019
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Apr. 30, 2020
Entity File Number	001-37784
Entity Registrant Name	GMS Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-2931287
Entity Address, Address Line One	100 Crescent Centre Parkway, Suite 800
Entity Address, City or Town	Tucker
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30084
City Area Code	800
Local Phone Number	392-4619
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	GMS
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 1,246.9
Entity Common Stock, Shares Outstanding		42,603,708
Entity Central Index Key	0001600438
Current Fiscal Year End Date	--04-30
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Current assets:
Cash and cash equivalents	$ 210,909	$ 47,338
Trade accounts and notes receivable, net of allowances of $5,141 and $6,432, respectively	405,254	445,771
Inventories, net	299,815	290,829
Prepaid expenses and other current assets	14,972	18,368
Total current assets	930,950	802,306
Property and equipment, net of accumulated depreciation of $158,554 and $123,583, respectively	305,467	282,349
Operating lease right-of-use assets	115,257
Goodwill	553,073	617,327
Intangible assets, net	361,884	429,313
Deferred income taxes	8,904	4,676
Other assets	13,247	13,583
Total assets	2,288,782	2,149,554
Current liabilities:
Accounts payable	213,230	173,751
Accrued compensation and employee benefits	67,590	62,858
Other accrued expenses and current liabilities	63,812	79,848
Current portion of long-term debt	50,201	42,118
Current portion of operating lease liabilities	33,040
Total current liabilities	427,873	358,575
Non-current liabilities:
Long-term debt, less current portion	1,047,279	1,099,077
Long-term operating lease liabilities	89,605
Deferred income taxes, net	12,018	10,226
Other liabilities	78,026	52,500
Total liabilities	1,654,801	1,520,378
Commitments and contingencies
Stockholders' equity:
Common stock, par value $0.01 per share, 500,000 shares authorized; 42,554 and 40,375 shares issued and outstanding as of April 30, 2020 and 2019, respectively	426	404
Preferred stock, par value $0.01 per share, 50,000 shares authorized; 0 shares issued and outstanding as of April 30, 2020 and 2019
Exchangeable shares		29,639
Additional paid-in capital	529,662	480,113
Retained earnings	168,975	145,594
Accumulated other comprehensive loss	(65,082)	(26,574)
Total stockholders' equity	633,981	629,176
Total liabilities and stockholders' equity	$ 2,288,782	$ 2,149,554

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Consolidated Balance Sheets
Trade accounts and notes receivable, allowances (in dollars)	$ 5,141	$ 6,432
Property and equipment, accumulated depreciation (in dollars)	$ 158,554	$ 123,583
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	42,554,000	40,375,000
Common stock, shares outstanding	42,554,000	40,375,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Consolidated Statements of Operations and Comprehensive Income
Net sales		$ 3,241,307	$ 3,116,032	$ 2,511,469
Cost of sales (exclusive of depreciation and amortization shown separately below)		2,178,093	2,111,913	1,692,893
Gross profit		1,063,214	1,004,119	818,576
Operating expenses:
Selling, general and administrative		784,081	739,460	633,877
Depreciation and amortization		116,533	117,459	65,530
Impairment of goodwill		63,074
Total operating expenses		963,688	856,919	699,407
Operating income		99,526	147,200	119,169
Other (expense) income:
Interest expense		(67,718)	(73,677)	(31,395)
Gain on legal settlement		14,029
Write-off of debt discount and deferred financing fees		(1,331)		(74)
Change in fair value of financial instruments			(6,395)	(6,125)
Other income, net		1,819	2,913	2,279
Total other expense, net		(53,201)	(77,159)	(35,315)
Income before taxes		46,325	70,041	83,854
Provision for income taxes		22,944	14,039	20,883
Net income		$ 23,381	$ 56,002	$ 62,971
Weighted average common shares outstanding:
Basic (in shares)		41,853	40,914	41,015
Diluted (in shares)		42,504	41,589	42,163
Net income per common share:
Basic (in dollars per share)	[1]	$ 0.56	$ 1.33	$ 1.54
Diluted (in dollars per share)	[1]	$ 0.55	$ 1.31	$ 1.49
Comprehensive income (loss)
Net income		$ 23,381	$ 56,002	$ 62,971
Foreign currency translation loss		(18,257)	(22,320)
Changes in other comprehensive income (loss), net of tax		(20,251)	(4,695)	1,325
Comprehensive income (loss)		$ (15,127)	$ 28,987	$ 64,296
[1]	See Note 19 for detailed calculations.

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock	Exchangeable Shares	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Apr. 30, 2017	$ 410		$ 488,459	$ 26,621	$ (884)	$ 514,606
Balance (in shares) at Apr. 30, 2017	40,971
Increase (Decrease) in Stockholders' Equity
Net income				62,971		62,971
Change in other comprehensive income (loss), net of tax					1,325	1,325
Equity-based compensation			1,513			1,513
Tax withholding related to net share settlements of stock options/equity awards			(1,441)			(1,441)
Exercise of stock options	$ 1		476			477
Exercise of stock options (in shares)	98
Balance at Apr. 30, 2018	$ 411		489,007	89,592	441	579,451
Balance (in shares) at Apr. 30, 2018	41,069
Increase (Decrease) in Stockholders' Equity
Net income				56,002		56,002
Issuance of Exchangeable Shares		$ 29,639				29,639
Repurchase and retirement of common stock	$ (10)		(16,510)			(16,520)
Repurchase and retirement of common stock (in shares)	(978)
Foreign currency translation loss					(22,320)	(22,320)
Change in other comprehensive income (loss), net of tax					(4,695)	(4,695)
Equity-based compensation			3,726			3,726
Tax withholding related to net share settlements of stock options/equity awards			(50)			(50)
Exercise of stock options	$ 2		2,536			2,538
Exercise of stock options (in shares)	205
Vesting of restricted stock units (in shares)	5
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,404			1,405
Issuance of common stock pursuant to employee stock purchase plan (in shares)	74
Balance at Apr. 30, 2019	$ 404	29,639	480,113	145,594	(26,574)	$ 629,176
Balance (in shares) at Apr. 30, 2019	40,375					40,375
Increase (Decrease) in Stockholders' Equity
Net income				23,381		$ 23,381
Exercise of Exchangeable Shares	$ 11	$ (29,639)	29,628
Exercise of Exchangeable Shares (in shares)	1,129
Foreign currency translation loss					(18,257)	(18,257)
Change in other comprehensive income (loss), net of tax					(20,251)	(20,251)
Equity-based compensation			6,878			6,878
Tax withholding related to net share settlements of stock options/equity awards			(532)			(532)
Exercise of stock options	$ 9		11,784			11,793
Exercise of stock options (in shares)	857
Vesting of restricted stock units	$ 1		(1)
Vesting of restricted stock units (in shares)	78
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,792			1,793
Issuance of common stock pursuant to employee stock purchase plan (in shares)	115
Balance at Apr. 30, 2020	$ 426		$ 529,662	$ 168,975	$ (65,082)	$ 633,981
Balance (in shares) at Apr. 30, 2020	42,554					42,554

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Cash flows from operating activities:
Net income	$ 23,381	$ 56,002	$ 62,971
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	116,533	117,459	65,530
Impairment of goodwill	63,074
Write-off and amortization of debt discount and debt issuance costs	4,541	3,332	2,851
Provision for losses on accounts and notes receivable	1,602	617	(622)
Provision for obsolescence of inventory	333	432	106
Effects of fair value adjustments to inventory	575	4,176	324
Increase in fair value of contingent consideration	1,600	759	195
Equity-based compensation	8,970	7,643	5,745
Loss (gain) on disposal and impairment of assets	658	(525)	(509)
Change in fair value of financial instruments		6,395	6,125
Deferred income taxes	926	(17,487)	(16,224)
Changes in assets and liabilities net of effects of acquisitions:
Trade accounts and notes receivable	41,424	(13,586)	(11,752)
Inventories	(4,579)	5,137	(35,098)
Prepaid expenses and other assets	6,623	(4,842)	(3,109)
Accounts payable	40,290	26,816	11,365
Accrued compensation and employee benefits	4,740	6,631	(236)
Other accrued expenses and liabilities	(7,612)	(5,344)	3,601
Cash provided by operating activities	303,079	193,615	91,263
Cash flows from investing activities:
Purchases of property and equipment	(25,193)	(18,770)	(23,741)
Proceeds from sale of assets	2,229	1,170	2,865
Acquisition of businesses, net of cash acquired	(24,136)	(583,092)	(28,333)
Cash used in investing activities	(47,100)	(600,692)	(49,209)
Cash flows from financing activities:
Repayments on the revolving credit facility	(837,424)	(937,176)	(617,230)
Borrowings from the revolving credit facility	880,698	981,148	513,878
Payments of principal on long-term debt	(109,968)	(9,968)	(5,776)
Payments of principal on finance lease obligations	(25,275)	(19,474)	(6,132)
Borrowings from term loan		996,840	577,616
Repayment of term loan		(571,840)	(477,616)
Repurchases of common stock		(16,520)
Payments for contingent consideration	(11,133)
Debt issuance costs	(1,286)	(7,933)	(3,283)
Proceeds from exercises of stock options	11,793	2,538	477
Payments for taxes related to net share settlement of equity awards	(532)	(50)	(1,441)
Other financing activities	1,793	1,405	(671)
Cash (used in) provided by financing activities	(91,334)	418,970	(20,178)
Effect of exchange rates on cash and cash equivalents	(1,074)	(992)
Increase in cash and cash equivalents	163,571	10,901	21,876
Cash and cash equivalents, beginning of period	47,338	36,437	14,561
Cash and cash equivalents, end of period	210,909	47,338	36,437
Supplemental cash flow disclosures:
Cash paid for income taxes	29,761	19,351	38,954
Cash paid for interest	63,745	66,435	28,613
Supplemental schedule of noncash activities:
Assets acquired under finance lease	50,484	111,826	9,086
Issuance of installment notes associated with equity-based compensation liability awards	5,163	5,356	12,433
(Decrease) increase in insurance claims payable and insurance recoverable	$ (634)	$ 619	$ (2,362)

Business, Basis of Presentation

Business, Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Apr. 30, 2020
Business, Basis of Presentation and Summary of Significant Accounting Policies
Business, Basis of Presentation and Summary of Significant Accounting Policies	1. Business, Basis of Presentation and Summary of Significant Accounting Policies Business ​ Founded in 1971, GMS Inc. (“we,” “our,” “us,” or the “Company”), through its wholly-owned operating subsidiaries, is a distributor of specialty building products including wallboard, suspended ceilings systems, or ceilings, steel framing and other complementary building products. We purchase products from many manufacturers and then distribute these goods to a customer base consisting of wallboard and ceilings contractors and homebuilders and, to a lesser extent, general contractors and individuals. We operate a network of more than 260 distribution centers across the United States and Canada. ​ Principles of Consolidation The consolidated financial statements of the Company include the accounts of its wholly owned subsidiaries. All material intercompany balances and transactions have been eliminated in consolidation. ​ Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. ​ Foreign Currency Translation Assets and liabilities of the Company’s Canadian subsidiaries are translated at the exchange rate prevailing at the balance sheet date, while income and expenses are translated at average rates for the period. Translation gains and losses are reported as a separate component of stockholders’ equity and other comprehensive income (loss). Gains and losses on foreign currency transactions are recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) within other income, net. Reclassifications ​ Certain amounts in the prior year financial statements have been reclassified to conform to the current year presentation. ​ Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. ​ Trade Accounts Receivable Accounts receivables are recorded at their net realizable value. The Company maintains an allowance for doubtful accounts for estimated losses due to the failure of customers to make required payments, as well as allowances for cash discounts. The Company’s estimate of the allowance for doubtful accounts is based on an assessment of individual past due accounts, historical write-off experience, accounts receivable aging and current economic trends. Account balances are written off when the potential for recovery is considered remote. ​ Inventories ​ Inventories consist of finished goods purchased for resale and include wallboard, ceilings, steel framing and other specialty building products. Inventories are valued at the lower of cost or market (net realizable value). The cost of inventories is determined by the moving average cost method. The Company routinely evaluates inventory for excess or obsolescence and considers factors such as historical usage rates and demand. ​ Property and Equipment Property and equipment is recorded at cost less accumulated depreciation. Property and equipment obtained through acquisition is stated at estimated fair value as of the acquisition date. Expenditures for improvements and betterments are capitalized, while the costs of maintenance and repairs are charged to operating expense as incurred. Gains and losses related to the sale of property and equipment are recorded in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). Depreciation expense for property and equipment of U.S. subsidiaries is determined using the straight-line method over the estimated useful lives of the various asset classes. The estimated useful lives of property and equipment are as follows: ​ ​ ​ ​ Buildings 25 - 39 years Furniture, fixtures and automobiles 3 - 5 years Warehouse and delivery equipment 4 - 10 years Leasehold improvements Shorter of estimated useful life or lease term ​ Depreciation expense for property and equipment of Canadian subsidiaries is recognized over the estimated useful lives of the various asset classes as follows: ​ ​ ​ ​ Vehicles and trucks 30% - 40% declining balance Furniture and fixtures 8% - 20% declining balance Buildings 4% declining balance Machinery and equipment 30% declining balance Leasehold improvements ​ Straight-line over shorter of estimated useful life or lease term ​ Goodwill Goodwill is the excess of the purchase price over the fair value of identifiable net assets acquired in business combinations accounted for under the acquisition method of accounting. The Company does not amortize goodwill. The Company tests its goodwill annually during the fourth quarter of its fiscal year or when events and circumstances indicate that those assets might not be recoverable. Impairment testing of goodwill is required at the reporting unit level (operating segment or one level below operating segment). Prior to performing the impairment test, the Company may make a qualitative assessment of the likelihood of goodwill impairment in order to determine whether a detailed quantitative analysis is required. The impairment test involves comparing the estimated fair values of the Company’s reporting units with the reporting units’ carrying amounts, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, a goodwill impairment loss is measured as the amount by which a reporting unit’s carrying amount exceeds its fair value, not to exceed the carrying amount of goodwill. ​ Intangible Assets Intangible assets consist of customer relationships, trade names and other assets acquired in conjunction with the purchases of businesses or purchases of assets from other companies. When management determines material intangible assets are acquired in conjunction with the purchase of a business, the Company determines the fair values of the identifiable intangible assets by considering management’s own analysis and an independent third-party valuation specialist’s appraisal. Intangible assets determined to have definite lives are amortized over their estimated useful lives. ​ Long-Lived Assets ​ The Company evaluates the recoverability of long-lived assets, including property and equipment, operating lease right-of-use assets and definite-lived intangible assets, for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Conditions that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used or a significant adverse change that would indicate the carrying amount of an asset or group of assets is not recoverable. For long-lived assets to be held and used, the Company recognizes an impairment loss if its carrying amount is not recoverable through its undiscounted cash flows and measures the impairment loss, if any, based on the difference between the carrying amount and fair value. Long-lived assets held for sale are reported at the lower of cost or fair value less costs to sell Insurance Liabilities The Company is self-insured for certain losses related to medical claims. The Company has stop-loss coverage to limit the exposure arising from medical claims. In addition, the Company has deductible-based insurance policies for certain losses related to general liability, workers’ compensation and automobile. The deductible amount per incident is $0.3 million, $0.5 million and $1.0 million for general liability, workers’ compensation and automobile, respectively. The coverage consists of a deductible layer, a primary layer, a self-insured buffer layer, a lead umbrella layer and excess layers. The primary layer of coverage is from $0.3 million, $0.5 million and $1.0 million for deductibles for general liability, workers’ compensation, and automobile liability, respectively, to $5.0 million. The Company self-insures a buffer layer from $5.0 million to $10.0 million. The umbrella and excess layers cover claims from $10.0 million to $100.0 million. The expected ultimate cost for claims incurred as of the balance sheet date is not discounted and is recognized as a liability. Insurance losses for claims filed and claims incurred but not reported are accrued based upon estimates of the aggregate liability for uninsured claims using loss development factors and actuarial assumptions followed in the insurance industry and historical loss development experience. As of April 30, 2020 and 2019, the aggregate liabilities for medical self-insurance were $3.8 million and $3.4 million, respectively, and are included in other accrued expenses and current liabilities in the Consolidated Balance Sheets. As of April 30, 2020 and 2019, reserves for general liability, workers’ compensation and automobile totaled $19.4 million and $17.7 million, respectively, and are included in other accrued expenses and current liabilities and other liabilities in the Consolidated Balance Sheets. As of April 30, 2020 and 2019, expected recoveries for medical self-insurance, general liability, workers’ compensation and automobile totaled $6.0 million and $6.0 million, respectively, and are included in prepaid expenses and other current assets and other assets in the Consolidated Balance Sheets. ​ Restructuring The Company recognizes a liability for costs associated with an exit or disposal activity when the liability is incurred. After the appropriate level of management approves the detailed restructuring plan and the appropriate criteria for recognition are met, the Company establishes accruals for employee termination and other costs, as applicable. During the first quarter of 2019, the Company initiated a reduction in workforce as part of a strategic cost reduction plan to improve operational efficiency. The Company recorded $5.0 million of restructuring costs during the year ended April 30, 2019 in connection with the reduction in workforce and certain other restructuring activities, consisting primarily of severance and other employee costs. As of April 30, 2019, all costs related to the reduction in workforce had been paid. During the fourth quarter of 2020, the Company initiated a restructuring plan to close one of its facilities. The Company recorded $2.2 million of restructuring costs, consisting of $1.9 million for impairment of the operating lease right-of-use asset and $0.3 million for severance and other employee costs. Restructuring costs are classified within selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). ​ Debt Issuance Costs The Company defers debt issuance costs and amortizes them over the term of the related debt. The Company uses the straight-line method to amortize debt issuance costs for its revolving credit facility and uses the effective interest method to amortize debt issuance costs for its term loan facilities. Amortization of debt issuance costs is recorded in interest expense in the Consolidated Statements of Operations and Comprehensive Income (Loss). The Company classifies debt issuance costs for its revolving credit facilities as an asset in the Consolidated Balance Sheets and classifies debt issuance costs for its term loan facilities as a reduction of the related debt in the Consolidated Balance Sheets. ​ Stock Appreciation Rights, Deferred Compensation and Liabilities to Noncontrolling Interest Holders Certain subsidiaries have equity-based compensation agreements with the subsidiary’s employees and minority stockholders. These agreements are stock appreciation rights, deferred compensation agreements and liabilities to noncontrolling interest holders. Since these agreements are typically settled in cash or notes, they are accounted for as liability awards and measured at fair value. See Note 13, “Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests,” for additional information with respect to these agreements. ​ Derivative Instruments The Company has entered into derivative instruments to manage its exposure to certain financial risks. The Company’s derivative financial instruments are recognized as either assets or liabilities in the Consolidated Balance Sheets and measured at fair value. Derivative instruments that do not qualify as a hedge or are not designated as a hedge are adjusted to estimated fair value in earnings. Derivative instruments that meet hedge criteria are formally designated as hedges. For derivative instruments designated as a cash flow hedge, the Company recognizes the change in fair value, net of taxes, to accumulated other comprehensive income (loss) in the Consolidated Balance Sheets, and an amount is reclassified out of accumulated other comprehensive income (loss) into earnings to offset the earnings impact that is attributable to the risk being hedged. For derivative instruments designated as a fair value hedge, the Company recognizes the loss or gain attributable to the risk being hedged in earnings in the period of change with a corresponding offset recorded to the item for which the risk is being hedged. The Company performs the effectiveness testing of its designated hedges on a quarterly basis and the changes in ineffective portions of the derivatives, if any, are recognized immediately in earnings. See Note 14, “Derivative Instruments,” for additional information with respect to the Company’s derivative instruments. ​ Revenue Recognition ​ The Company recognizes revenue upon transfer of control of promised goods to customers at an amount that reflects the consideration the Company expects to receive in exchange for those goods. Revenue is recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities. The Company includes shipping and handling costs billed to customers in net sales. These costs are recognized as a component of selling, general and administrative expenses when the Company does not bill the customer. See Note 2, “Revenue,” for information on the Company’s revenue recognition. Cost of Sales Cost of sales reflects the direct cost of goods purchased from third parties, rebates earned from vendors, adjustments for inventory reserves and the cost of inbound freight. Vendor Rebates Typical arrangements with vendors provide for the Company to receive a rebate of a specified amount after it achieves any of a number of measures generally related to the volume of our purchases over a period of time. The Company records these rebates to effectively reduce its cost of sales in the period in which the Company sells the product. Throughout the year, the Company estimates the amount of rebates receivable for the periodic programs based upon the expected level of purchases. The Company accrues for the receipt of vendor rebates based on purchases and also reduces inventory to reflect the deferral of cost of sales. ​ Selling, General and Administrative Expenses ​ ​ Advertising Expense The cost of advertising is expensed as incurred and included in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). Advertising expense was $3.3 million, $1.9 million and $1.8 million during the years ended April 30, 2020, 2019 and 2018, respectively. ​ Equity-Based Compensation As of April 30, 2020, the Company had various stock-based compensation plans, which are more fully described in Note 12, “Equity-Based Compensation.” The Company estimates the fair value of stock options using the Black-Scholes valuation model and determines the fair value of restricted stock units based on the quoted price of GMS’s common stock on the date of grant. Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized based on the difference between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Inherent in the measurement of deferred balances are certain judgments and interpretations of existing tax law and published guidance as applicable to our operations. The Company evaluates its deferred tax assets to determine if valuation allowances are required. In assessing the realizability of deferred tax assets, we consider both positive and negative evidence in determining whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The primary negative evidence considered includes the cumulative operating losses generated in prior periods. The primary positive evidence considered includes the reversal of deferred tax liabilities related to depreciation and amortization that would occur within the same jurisdiction and during the carry-forward period necessary to absorb the federal and state net operating losses and other deferred tax assets. The reversal of such liabilities would utilize the federal and state net operating losses and other deferred tax assets. The Company records amounts for uncertain tax positions that management believes are supportable, but are potentially subject to successful challenge by the applicable taxing authority. Consequently, changes in our assumptions and judgments could materially affect amounts recognized related to income tax uncertainties and may affect our results of operations or financial position. We believe our assumptions for estimates are reasonable, although actual results may have a positive or negative material impact on the balances of such tax positions. Historically, the variation of estimates to actual results is not significant and material variation is not expected in the future. ​ Concentrations of Risk COVID-19 Pandemic ​ Credit Risk. geographically diverse customers Additionally, the Company maintains allowances for potential credit losses. As of April 30, 2020 and 2019, no customer accounted for more than 10% of gross accounts receivable. ​ Supply Risk. ​ Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Authoritative guidance for fair value measurements establishes a three-level hierarchy that prioritizes the inputs to valuation models based upon the degree to which they are observable. The three levels of the fair value measurement hierarchy are as follows: Level 1 Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. Level 2 Inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 Inputs are unobservable inputs for which little or no market data exists, therefore requiring an entity to develop its own assumptions. ​ The carrying values of the Company’s cash, cash equivalents, trade receivables and trade payables approximate their fair values because of their short-term nature. Based on borrowing rates available to the Company for loans with similar terms, the carrying values of the Company’s debt instruments approximate fair value. See Note 15, “Fair Value Measurements,” for additional information with respect to the Company’s fair value measurements. ​ Earnings Per Share Basic earnings per share is computed by dividing net income available to common stockholders by the weighted average number of outstanding shares of common stock for the period. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock, including stock options and restricted stock units (collectively “Common Stock Equivalents”), were exercised or converted into common stock The dilutive effect of outstanding stock options and stock units is reflected in diluted earnings per share by application of the treasury stock method. In applying the treasury stock method for stock-based compensation arrangements, the assumed proceeds are computed as the sum of the amount the employee must pay upon exercise and the amount of compensation cost attributed to future services and not yet recognized. Common Stock Equivalents The holders of the Company’s Exchangeable Shares (as defined in Note 3, “Business Acquisitions” and further described in Note 11, “Stockholders’ Equity”) were entitled to receive dividends or distributions that were equal to any dividends or distributions on the Company’s common stock. As a result, when the Exchangeable Shares were outstanding, they were classified as a participating security and thereby required the allocation of income that would have otherwise been available to common stockholders when calculating earnings per share. Diluted earnings per share was calculated by utilizing the most dilutive result of the if-converted and two-class methods. In both methods, net income attributable to common stockholders and the weighted-average common shares outstanding are adjusted to account for the impact of the assumed issuance of potential common shares that are dilutive, subject to dilution sequencing rules. Recently Adopted Accounting Pronouncements Leases – In February 2016, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance on accounting for leases. The new standard establishes a right-of-use (“ROU”) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than twelve months. Leases are classified as either finance or operating, with such classification affecting the pattern of expense recognition in the statement of operations. The new standard was effective for the Company’s fiscal year beginning May 1, 2019 (the first day of fiscal 2020), including interim reporting periods within that fiscal year. A modified transition approach was required for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. ​ On July 30, 2018, the FASB issued new guidance that provided entities with an additional (and optional) transition method to adopt the new lease standard. Under this new transition method, an entity initially applies the new lease standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. ​ The Company adopted the new lease standard on May 1, 2019 using the optional transition method. The Company elected the package of practical expedients permitted in the guidance, which among other things, allows the Company to carry forward the historical accounting relating to lease identification and classification for existing leases upon adoption. The Company also elected to use the practical expedient to not separate lease and nonlease components. The Company did not elect the hindsight practical expedient. The Company made an accounting policy election to not recognize an ROU asset and lease liability for leases with an initial term of 12 months or less. ​ The adoption of the standard resulted in the recording of operating lease ROU assets and operating lease liabilities of $118.8 million on the Consolidated Balance Sheet as of the adoption date. The Company also reclassified deferred rent of $4.8 million from liabilities into its operating lease ROU assets. The adoption did not have a material impact on the Company’s Statement of Operations or Statement of Cash Flows. See Note 8, “Leases,” for information and disclosures regarding leases. ​ Goodwill – In January 2017, the FASB issued authoritative guidance that simplifies the accounting for goodwill impairments by eliminating Step 2 from the goodwill impairment test. Under the new guidance, goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value. The new standard is effective for annual and any interim impairment tests for periods beginning after December 15, 2019. Early adoption is permitted. The Company adopted the new guidance on February 1, 2020 (the first day of its fiscal fourth quarter). ​ Recently Issued Accounting Pronouncements ​ Credit Losses – In June 2016, the FASB issued new guidance on credit losses on financial instruments. This guidance introduces a revised approach to the recognition and measurement of credit losses of certain financial instruments, including trade receivables, emphasizing an updated model based on expected losses rather than incurred losses. This new guidance is effective for annual reporting periods, and interim reporting periods contained therein, beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact of this guidance on its financial statements and related disclosures. ​ Fair Value Measurement Disclosures – In August 2018, the FASB issued new guidance that changes certain fair value measurement disclosure requirements. This guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. An entity is permitted to early adopt all of the disclosure changes or early adopt only the removed disclosure requirements and delay adoption of the additional disclosures until the effective date of this amendment. Except for changes to certain disclosures related to fair value measurements, the Company does not expect the adoption of this guidance to have a material impact on its financial statements. ​ Reference Rate Reform – In March 2020, the FASB issued new guidance to temporarily ease the potential burden in accounting for reference rate reform. The guidance provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rates that are expected to be discontinued, such as the London Interbank Offered Rate ("LIBOR"). The guidance was effective upon issuance and generally can be applied through December 31, 2022. The Company expects to elect optional expedients and exceptions provided by the guidance, as needed, related to its debt instruments, which include interest rates based on a LIBOR rate. The Company will evaluate and disclose the impact of this guidance in the period of election, as well as the nature and reason for doing so.

Revenue

Revenue	12 Months Ended
	Apr. 30, 2020
Revenue
Revenue	2. Revenue ​ Revenue Recognition ​ Revenue is recognized upon transfer of control of promised goods to customers at an amount that reflects the consideration the Company expects to receive in exchange for those goods. Revenue is recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities. The Company includes shipping and handling costs billed to customers in net sales. These costs are recognized as a component of selling, general and administrative expenses when the Company does not bill the customer. See Note 18, “Segments,” for information regarding disaggregation of revenue, including revenue by product and by geographic area. ​ Performance Obligations ​ The Company satisfies its performance obligations at a point in time, which is upon delivery of products. The Company’s payment terms vary by the type and location of its customers. The amount of time between point of sale and when payment is due is not significant and the Company has determined its contracts do not include a significant financing component. ​ The Company’s contracts with customers involve performance obligations that are one year or less. Therefore, the Company applied the standard’s optional exemption that permits the omission of information about its unfulfilled performance obligations as of the balance sheet dates. ​ Significant Judgements ​ The Company’s contracts may include terms that could cause variability in the transaction price, including customer rebates, returns and cash discounts for early payment. Variable consideration is estimated and included in the transaction price based on the expected value method. These estimates are based on historical experience, anticipated performance and other factors known at the time. The Company only includes estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. ​ Contract Balances Receivables from contracts with customers were $393.6 million and $431.4 million as of April 30, 2020 and 2019, respectively. The Company did not have material amounts of contract assets or liabilities as of April 30, 2020 or 2019.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Apr. 30, 2020
Business Acquisitions
Business Acquisitions	3. Business Acquisitions Fiscal 2020 Acquisitions ​ ​ ​ ​ ​ ​ Company Name Form of Acquisition Date of Acquisition J.P. Hart Lumber Company ​ Purchase of net assets ​ June 3, 2019 Rigney Building Supplies Ltd. ​ Purchase of 100% of outstanding common stock ​ November 1, 2019 Trowel Trades Supply, Inc. ​ Purchase of net assets ​ February 1, 2020 ​ ​ ​ ​ ​ ​ ​ ​ Preliminary ​ ​ Acquisition ​ ​ Accounting ​ ​ (in thousands) Cash ​ $ 713 Trade accounts and notes receivable ​ 5,149 Inventories ​ 7,194 Other current assets ​ 72 Property and equipment ​ 6,788 Customer relationships ​ ​ 4,252 Tradenames ​ 644 Goodwill ​ 5,291 Liabilities assumed ​ (5,028) Fair value of consideration transferred ​ $ 25,075 ​ ​ Fiscal 2019 Acquisitions Acquisition of Titan On June 1, 2018, the Company acquired all of the outstanding equity interests of WSB Titan (“Titan”), a distributer of wallboard, lumber, insulation and other complementary commercial and residential building materials. Titan is a gypsum specialty dealer with 30 locations across five provinces in Canada. The stated purchase price was $627.0 million ($800.0 million Canadian dollars). As part of the consideration, certain members of Titan’s To finance this transaction, on June 1, 2018, the Company entered into a Third Amendment to its First Lien Credit Agreement (the “Third Amendment”) that provides for a new first lien term loan facility under the first lien credit agreement in the aggregate principal amount of $996.8 million due in June 2025 that bears interest at a floating rate based on LIBOR, with a 0% floor, plus 2.75%. The Company also drew down $143.0 million under its Asset Based Lending Facility (“ABL Facility”). The net proceeds from the new first lien term loan facility, ABL Facility and cash on hand were used to repay the Company’s existing first lien term loan facility of $571.8 million under the Credit Agreement and to finance its acquisition of Titan. The fair value of consideration transferred was $611.1 million, after adjusting for foreign currency changes in the stated purchase price and other fair value changes, which consisted of $581.5 million in cash and $29.6 million for the fair value of the 1.1 million Exchangeable Shares. See Note 11, “Stockholders’ Equity,” for more information on the Exchangeable Shares. The Company also assumed certain contingent consideration arrangements that relate to previous acquisitions of Titan. The contingent consideration arrangements were based on performance of Titan’s business and were substantially paid in cash in fiscal 2020. The following table summarizes the acquisition accounting: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Preliminary ​ ​ ​ ​ Final ​ ​ Acquisition ​ Adjustments/ ​ Acquisition ​ ​ Accounting ​ Reclassifications ​ Accounting ​ ​ (in thousands) Cash $ 5,573 ​ $ — ​ $ 5,573 Trade accounts and notes receivable ​ 84,039 ​ 970 ​ 85,009 Inventories ​ ​ 60,272 ​ ​ — ​ ​ 60,272 Prepaid and other current assets ​ 8,334 ​ — ​ 8,334 Property and equipment ​ 37,263 ​ — ​ 37,263 Goodwill ​ ​ 196,524 ​ ​ (2,726) ​ ​ 193,798 Intangible assets ​ ​ 289,423 ​ ​ (2,469) ​ ​ 286,954 Accounts payable and accrued expenses ​ ​ (40,833) ​ ​ (970) ​ ​ (41,803) Contingent consideration ​ ​ (12,039) ​ ​ — ​ ​ (12,039) Deferred income taxes ​ (14,337) ​ 2,085 ​ (12,252) Fair value of consideration transferred ​ $ 614,219 ​ $ (3,110) ​ $ 611,109 ​ Goodwill arising from the acquisition is attributable to synergies achieved through the streamlining of operations combined with improved margins attainable through increased market presence. All of the goodwill is assigned to the Company’s geographic divisions reportable segment. The goodwill is not deductible for income tax purposes. ​ Other Fiscal 2019 Acquisitions ​ On August 7, 2018, the Company acquired Charles G. Hardy, Inc. (“CGH”). CGH is an interior building products distributor in Paramount, California. On March 4, 2019, the Company acquired Commercial Builders Group, LLC (“CBG”). CBG is an interior building products distributor in LaPlace, Louisiana. The impact of these acquisitions is not material to the Company’s Consolidated Financial Statements. Fiscal 2018 Acquisitions In fiscal 2018, the Company completed the following acquisitions, with an aggregate purchase price of $24.4 million of cash consideration. The purpose of these acquisitions was to expand the geographical coverage of the Company and grow the business. ​ ​ ​ ​ ​ ​ Company Name Form of Acquisition Date of Acquisition ASI Building Products, LLC ​ Purchase of net assets ​ August 1, 2017 Washington Builders Supply, Inc. ​ Purchase of net assets ​ October 2, 2017 Southwest Building Materials, Ltd. ​ Purchase of net assets ​ December 4, 2017 California-based distribution business of Grabber Construction Products, Inc. ​ Purchase of net assets ​ April 2, 2018 CMH Distributing, Inc. ​ Purchase of net assets ​ April 2, 2018 ​ The following table summarizes the acquisition accounting: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Preliminary ​ ​ ​ ​ Final ​ ​ Acquisition ​ Adjustments/ ​ Acquisition ​ ​ Accounting ​ Reclassifications ​ Accounting ​ ​ (in thousands) Trade accounts and notes receivable ​ $ 4,872 ​ $ — ​ $ 4,872 Inventories ​ ​ 4,321 ​ ​ — ​ ​ 4,321 Property and equipment ​ 1,081 ​ — ​ 1,081 Tradenames ​ 1,000 ​ — ​ 1,000 Vendor agreement ​ 1,000 ​ — ​ 1,000 Other intangible assets ​ 620 ​ — ​ 620 Customer relationships ​ 9,358 ​ — ​ 9,358 Goodwill ​ 4,145 ​ 8 ​ 4,153 Liabilities assumed ​ (1,951) ​ — ​ (1,951) Fair value of consideration transferred ​ $ 24,446 ​ $ 8 ​ $ 24,454 ​ Goodwill recognized is attributable to synergies achieved through the streamlining of operations combined with improved margins attainable through increased market presence and is all attributable to our geographic divisions reportable segment. The goodwill related to these acquisitions is deductible for U.S. federal income tax purposes. ​

Property and Equipment

Property and Equipment	12 Months Ended
	Apr. 30, 2020
Property and Equipment
Property and Equipment	4. Property and Equipment The Company’s property and equipment consisted of the following as of April 30, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 ​ ​ (in thousands) Land ​ $ 52,581 ​ $ 52,031 Buildings and leasehold improvements ​ 110,322 ​ 99,300 Machinery and equipment ​ 300,133 ​ 252,504 Construction in progress ​ 985 ​ 2,097 Total property and equipment ​ 464,021 ​ 405,932 Less: accumulated depreciation and amortization ​ 158,554 ​ 123,583 Total property and equipment, net of accumulated depreciation ​ $ 305,467 ​ $ 282,349 ​ Depreciation expense for property and equipment, which includes amortization of property under finance leases, was $51.3 million, $46.5 million and $24.1 million during the years ended April 30, 2020, 2019 and 2018 respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Apr. 30, 2020
Goodwill and Intangible Assets
Goodwill and Intangible Assets	5. Goodwill and Intangible Assets Goodwill ​ ​ ​ ​ ​ ​ Carrying ​ ​ Amount ​ ​ (in thousands) Balance as of April 30, 2018 ​ $ 427,645 Goodwill recognized from acquisitions ​ ​ 196,267 Purchase price adjustments from prior periods ​ ​ 8 Translation adjustment ​ (6,593) Balance as of April 30, 2019 ​ ​ 617,327 Impairment of goodwill ​ ​ (63,074) Goodwill recognized from acquisitions ​ ​ 5,291 Translation adjustment ​ (6,471) Balance as of April 30, 2020 ​ $ 553,073 ​ All goodwill relates to our geographic divisions reportable segment. ​ The Company recognized a $63.1 million non-cash impairment charge to write off goodwill related to its Canada reporting unit in conjunction with its annual goodwill impairment test performed in the fourth quarter of fiscal 2020. impairment of goodwill in the Consolidated Statement of Operations and Comprehensive Income (Loss) for the year ended April 30, 2020. The primary factors contributing to the impairment was an increase in the discount rate and a decrease in market multiples, combined with a decrease in the reporting unit’s forecasted near-term cash flows, primarily resulting from COVID-19 driven economic uncertainty. Consistent with the Company’s adoption of the new goodwill guidance in the fourth quarter of 2020, the impairment charge was equal to the excess of the reporting unit’s carrying value over its fair value. As of April 30, 2020, the Company had $120.9 million of remaining goodwill related to its Canada reporting unit. The ​ The Company identified reporting units for evaluating goodwill for the fiscal annual impairment test, which were Central, Midwest, Northeast, Southern, Southeast, Western and Canada. Each of these reporting units constitutes a business for which discrete financial information is available and segment management regularly reviews the operating results. The Company evaluates its reporting units on an annual basis. ​ The Company estimated the fair values of its reporting units based on weighting of the income and market approaches. These models use significant unobservable inputs, or Level 3 inputs, as defined by the fair value hierarchy. Under the income approach, we calculate the fair value of the reporting unit based on the present value of estimated cash flows using a discounted cash flow method. The significant assumptions used in the discounted cash flow method included internal forecasts and projections developed by management for planning purposes, available industry/market data, discount rates and the growth rate to calculate the terminal value. Under the market approaches, the fair value was estimated using the guideline company method. The Company selected guideline companies in the industry in which each reporting unit operates. The Company primarily uses revenue and EBITDA multiples based on the multiples of the selected guideline companies. ​ Intangible Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ Weighted ​ April 30, 2020 ​ ​ Useful ​ Average ​ Gross ​ ​ ​ Net ​ ​ Lives ​ Amortization ​ Carrying ​ Accumulated ​ Carrying ​ (years) Period Amount Amortization Value ​ ​ (dollars in thousands) Customer relationships ​ 5 - 16 ​ 12.8 ​ $ 516,928 ​ $ 270,029 ​ $ 246,899 Definite-lived tradenames ​ 5 - 20 ​ 16.3 ​ 55,654 ​ 10,474 ​ 45,180 Vendor agreements ​ 8 - 10 ​ 8.3 ​ 6,644 ​ 4,567 ​ 2,077 Developed technology ​ 5 ​ 4.9 ​ ​ 5,036 ​ ​ 1,963 ​ ​ 3,073 Leasehold interests ​ 1 - 15 ​ 7.6 ​ 3,679 ​ 2,101 ​ 1,578 Other ​ 3 - 5 ​ 3.4 ​ ​ 4,157 ​ ​ 2,447 ​ ​ 1,710 Totals ​ ​ ​ ​ ​ $ 592,098 ​ $ 291,581 ​ $ 300,517 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ Weighted ​ April 30, 2019 ​ ​ Useful ​ Average ​ Gross ​ ​ ​ Net ​ ​ Lives Amortization Carrying Accumulated Carrying ​ (years) Period Amount Amortization Value ​ ​ (dollars in thousands) Customer relationships ​ 5 - 16 ​ 12.8 ​ $ 520,703 ​ $ 214,044 ​ $ 306,659 Definite-lived tradenames ​ 5 - 20 ​ 16.3 ​ 56,018 ​ 6,993 ​ 49,025 Vendor agreements ​ 8 - 10 ​ 8.3 ​ 6,644 ​ 3,761 ​ 2,883 Developed technology ​ 5 ​ 4.9 ​ ​ 5,209 ​ ​ 971 ​ ​ 4,238 Leasehold interests ​ 1 - 15 ​ 7.6 ​ 3,707 ​ 1,502 ​ 2,205 Other ​ 3 - 5 ​ 3.4 ​ ​ 4,118 ​ ​ 1,182 ​ ​ 2,936 Totals ​ ​ ​ ​ ​ $ 596,399 ​ $ 228,453 ​ $ 367,946 ​ Definite-lived intangible assets are amortized over their estimated useful lives. The Company amortizes its customer relationships using an accelerated method to match the estimated cash flow generated by such assets, and amortizes its other definite-lived intangibles using the straight-line method because a pattern to which the expected benefits will be consumed or otherwise used up could not be reliably determined. Amortization expense related to definite-lived intangible assets was $65.2 million, $71.0 million and $41.5 million during the years ended April 30, 2020, 2019 and 2018, respectively, and is recorded in depreciation and amortization expense in the Consolidated Statements of Operations and Comprehensive Income (Loss). ​ Based on the current amount of definite-lived intangible assets, the Company expects to record amortization expense of $55.2 million, $46.1 million, $38.3 million, $31.2 million, $25.7 million and $104.0 million during the years ending April 30, 2021, 2022, 2023, 2024, 2025 and thereafter, respectively. Actual amortization expense to be reported in future periods could differ materially from these estimates as a result of acquisitions, changes in useful lives, foreign currency exchange rate fluctuations and other relevant factors. ​ The Company’s indefinite-lived intangible assets, other than goodwill, consist of tradenames that had a carrying amount of $61.4 million as of April 30, 2020 and 2019.

Other Accrued Expenses and Curr

Other Accrued Expenses and Current Liabilities	12 Months Ended
	Apr. 30, 2020
Other Accrued Expenses and Current Liabilities
Other Accrued Expenses and Current Liabilities	6. Other Accrued Expenses and Current Liabilities The Company’s other accrued expenses and current liabilities consisted of the following as of April 30, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 ​ ​ (in thousands) Insurance related liabilities ​ $ 12,922 ​ $ 14,110 Customer rebates payable ​ 10,211 ​ 7,944 Sales taxes payable ​ 9,493 ​ 10,448 Reserve for sales returns ​ ​ 4,081 ​ ​ 4,701 Income taxes payable ​ ​ 2,844 ​ ​ 14,063 Real estate and personal property taxes ​ 2,182 ​ 2,010 Contingent consideration ​ 2,018 ​ 13,073 Other ​ 20,061 ​ 13,499 Total other accrued expenses and current liabilities ​ $ 63,812 ​ $ 79,848 ​

Long-Term Debt

Long-Term Debt	12 Months Ended
	Apr. 30, 2020
Long-Term Debt
Long-Term Debt	7. Long-Term Debt The Company’s long-term debt consisted of the following as of April 30, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 ​ ​ (in thousands) Term Loan Facility (1) (2) ​ $ 866,301 ​ $ 972,650 ABL Facility ​ 80,000 ​ 43,972 Finance lease obligations ​ 128,767 ​ 109,286 Installment notes at fixed rates up to 5.0%, due in monthly and annual installments through 2024 (3) ​ 15,218 ​ 15,287 Canadian Facility ​ 7,194 ​ ​ — Carrying value of debt ​ 1,097,480 ​ 1,141,195 Less current portion ​ 50,201 ​ 42,118 Long-term debt ​ $ 1,047,279 ​ $ 1,099,077 (1) Net of unamortized discount of $1,602 and $2,149 as of April 30, 2020 and 2019, respectively. (2) Net of deferred financing costs of $9,000 and $12,072 as of April 30, 2020 and 2019, respectively. (3) Net of unamortized discount of $1,098 and $1,200 as of April 30, 2020 and 2019, respectively. ​ ​ ​ Term Loan Facility The Company’s wholly-owned subsidiaries, GYP Holdings II Corp., as parent guarantor (in such capacity, “Holdings”), and GYP Holdings III Corp., as borrower (in such capacity, the “Borrower” and, together with Holdings and the Subsidiary Guarantors (as defined below), the “Loan Parties”), have a senior secured first lien term loan facility (the “Term Loan Facility”). The Term Loan Facility permits the Borrower to add one or more incremental term loans up to a fixed amount of $100.0 million plus a certain amount depending on a secured first lien leverage ratio test included in the Term Loan Facility. As of April 30, 2020, the Term Loan Facility amortized in nominal quarterly installments of $2.5 million, or 0.25% of the aggregate principal amount of the Term Loan Facility and had a maturity date of June 1, 2025. Provided that the individual affected lenders agree accordingly, the maturities of the Term Loan Facility may, upon the Borrower’s request and without the consent of any other lender, be extended. GYP Holdings II Corp., the sole entity between borrower and financial reporting entity, is a holding company with no other operations, assets, liabilities or cash flows other than through its ownership of GYP Holdings III Corp. (borrower) and its operating subsidiaries. On June 7, 2017, the Company entered into the Second Amendment to First Lien Credit Agreement (the “Second Amendment”), among the Borrower, Holdings, the other Loan Parties party thereto, Credit Suisse AG, as administrative agent and as 2017 incremental first lien lender. The Second Amendment provided for a new first lien term loan facility in the aggregate principal amount of $577.6 million due on April 1, 2023 with interest at a floating rate based on LIBOR, with a 1.00% floor, plus 3.00%, representing a fifty On June 1, 2018, the Company entered into the Third Amendment that provided for a new first lien term loan facility in the aggregate principal amount of $996.8 million due in June 2025 that bears interest at a floating rate based on LIBOR plus 2.75%, with a 0% floor. The net proceeds from the new first lien term loan facility were used to repay the Company’s existing Term Loan Facility outstanding balance of $571.8 million and to finance the acquisition of Titan. On September 30, 2019, the Company made a $50.0 million prepayment of outstanding principal amount of its Term Loan Facility. On March 6, 2020, the Company made an additional $50.0 million prepayment of outstanding principal amount of its Term Loan Facility. The Company recorded total write-offs of debt discount and deferred financing fees of $1.3 million, which is included in write-off of discount and deferred financing fees in the Consolidated Statement of Operations and Comprehensive Income . Asset Based Lending Facility The Company has an ABL Facility that provides for aggregate revolving commitments of $445.0 million (including same day swing line borrowings of $44.5 million). GYP Holdings III Corp. is the lead borrower (in such capacity, the “Lead Borrower”). Extensions of credit under the ABL Facility are limited by a borrowing base calculated periodically based on specified percentages of the value of eligible inventory and eligible accounts receivable, subject to certain reserves and other adjustments. On September 30, 2019, the Company amended its ABL Facility to, among other things, increase the revolving commitments from $345.0 million to $445.0 million, extend the maturity date to September 30, 2024 and remove the highest pricing level applicable to borrowings under the ABL Facility. The other material terms of the ABL Facility remained unchanged. At the Company’s option, the interest rates applicable to the loans under the ABL Facility are based at LIBOR or base rate plus, in each case, an applicable margin. The margins applicable for each elected interest rate are subject to a pricing grid, as defined in the ABL Facility agreement, based on average daily availability for the most recent fiscal quarter. As of April 30, 2020, the applicable rate of interest was 1.82%. The ABL Facility also contains an unused commitment fee subject to utilization, as included in the ABL Facility agreement. In March 2020, the Company drew $80.0 million under the ABL Facility as a precautionary measure to provide financial flexibility and liquidity in response to volatile financial market conditions resulting from the COVID-19 pandemic. As of April 30, 2020, the Company had available borrowing capacity of $353.9 million under the ABL Facility. The ABL Facility will mature on September 30, 2024 unless the individual affected lenders agree to extend the maturity of their respective loans under the ABL Facility upon the Company’s request and without the consent of any other lender. The ABL Facility contains a cross default provision with the Term Loan Facility. Terms of the ABL Facility and Term Loan Facilities Collateral The ABL Facility is collateralized by (a) first priority perfected liens on the following assets of the Loan Parties: (i) accounts receivable; (ii) inventory; (iii) deposit accounts; (iv) cash and cash equivalents; (v) tax refunds and tax payments; (vi) chattel paper; and (vii) documents, instruments, general intangibles, securities accounts, books and records, proceeds and supporting obligations related to each of the foregoing, subject to certain exceptions (collectively, “ABL Priority Collateral”) and (b) second priority perfected liens on the remaining assets of the Loan Parties not constituting ABL Priority Collateral, subject to customary exceptions (collectively, “Term Priority Collateral”) and excluding real property. The Term Loan Facility is collateralized by (a) first priority liens on the Term Priority Collateral and (b) second priority liens on the ABL Priority Collateral, subject to customary exceptions. ​ ​ Prepayments ● 100% of the net proceeds of certain asset sales and issuances or incurrences of nonpermitted indebtedness; and ● 50% of annual excess cash flow for any fiscal year, such percentage to decrease to 25% or 0% depending on the attainment of certain total leverage ratio targets. As of April 30, 2020, there was no prepayment required related to excess cash flow. The ABL Facility may be prepaid at the Company’s option at any time without premium or penalty and will be subject to mandatory prepayment if the outstanding ABL Facility exceeds the lesser of the (i) borrowing base and (ii) the aggregate amount of commitments. Mandatory prepayments do not result in a permanent reduction of the lenders’ commitments under the ABL Facility. Guarantees Covenants The Term Loan Facility contains a number of covenants that limit the Company’s ability and the ability of the Company’s restricted subsidiaries, as described in the respective credit agreement, to: incur more indebtedness; pay dividends, redeem or repurchase stock or make other distributions; make investments; create restrictions on the ability of our restricted subsidiaries to pay dividends to us or make other intercompany transfers; create liens securing indebtedness; transfer or sell assets; merge or consolidate; enter into certain transactions with our affiliates; and prepay or amend the terms of certain indebtedness. The Company was in compliance with all covenants as of April 30, 2020. Events of Default ​ Canadian Revolving Credit Facility Installment Notes Debt Maturities As of April 30, 2020, the maturities of long-term debt were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan ​ ​ ABL ​ Finance ​ Installment ​ Canadian ​ ​ ​ ​ Facility(1) ​ Facility Leases Notes(2) ​ Facility ​ Total Year ending April 30, ​ (in thousands) 2021 ​ $ 9,968 ​ $ — ​ $ 35,530 ​ $ 4,874 ​ $ — ​ $ 50,372 2022 ​ 9,968 ​ ​ — ​ ​ 32,547 ​ ​ 4,438 ​ ​ — ​ 46,953 2023 ​ 9,968 ​ ​ — ​ ​ 27,062 ​ ​ 4,404 ​ ​ 7,194 ​ 48,628 2024 ​ 9,968 ​ ​ — ​ ​ 19,974 ​ ​ 1,781 ​ ​ — ​ 31,723 2025 ​ 9,968 ​ ​ 80,000 ​ ​ 9,983 ​ ​ 819 ​ ​ — ​ 100,770 Thereafter ​ 827,063 ​ ​ — ​ ​ 3,671 ​ ​ — ​ ​ — ​ 830,734 ​ ​ $ 876,903 ​ $ 80,000 ​ $ 128,767 ​ $ 16,316 ​ $ 7,194 ​ $ 1,109,180 ​ (1) (2)

Leases

Leases	12 Months Ended
	Apr. 30, 2020
Leases
Leases	8. Leases ​ The Company leases office and warehouse facilities, distribution equipment and its fleet of vehicles. The Company’s leases have lease terms ranging from one to eleven years . The Company’s facility leases generally contain renewal options for periods ranging from one to five years . The exercise of lease renewal options is typically at the Company’s sole discretion. The Company does not recognize ROU assets or lease liabilities for renewal options unless it is determined that the Company is reasonably certain of exercising renewal options at lease inception. Certain of the Company’s equipment leases include options to purchase the leased property and certain of the Company’s equipment leases contain residual value guarantees. Any residual value payment deemed probable is included in the Company’s lease liability. The Company’s lease agreements do not contain any material restrictive covenants. ​ The Company determines if an arrangement is a lease at inception and evaluates whether the lease meets the classification criteria of a finance or operating lease. Operating leases are included in operating lease right-of-use assets, current portion of operating lease liabilities and long-term operating lease liabilities in the Consolidated Balance Sheet. Finance leases are included in property and equipment, current portion of long-term debt and long-term debt in the Consolidated Balance Sheet. ​ Lease ROU assets and lease liabilities are recognized at the commencement date based on the present value of the future lease payments over the lease term. For leases that do not provide an implicit rate, the Company uses its incremental borrowing rate in determining the present value of future payments. The Company determines its incremental borrowing rate based on the applicable lease terms and the current economic environment. Lease ROU assets also include any lease payments made in advance and excludes lease incentives and initial direct costs incurred. Some of the Company’s lease agreements contain rent escalation clauses (including index-based escalations), rent holidays, capital improvements funding or other lease concessions. Lease expense is recognized on a straight-line basis based on the fixed component over the lease term. Variable lease costs consist primarily of taxes, insurance and common area or other maintenance costs for leased facilities and vehicles and equipment, which are paid based on actual costs incurred. ​ The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ Year ​ ​ Ended ​ ​ April 30, 2020 ​ ​ (in thousands) Finance lease cost: ​ ​ ​ Amortization of right-of-use assets ​ $ 24,352 Interest on lease liabilities ​ ​ 13,316 Operating lease cost ​ ​ 42,846 Variable lease cost ​ ​ 12,555 Total lease cost ​ $ 93,069 ​ Operating lease cost, including variable lease cost, is included in selling, general and administrative expenses; amortization of finance ROU assets is included in depreciation and amortization; and interest on finance lease liabilities is included in interest expense in the Consolidated Statements of Operations and Comprehensive Income (Loss). Rent expense under operating leases was $53.5 million and $63.9 million during the years ended April 30, 2019 and 2018, respectively, and is included in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ Year ​ ​ Ended ​ ​ April 30, 2020 ​ ​ (in thousands) Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ Operating cash flows from operating leases ​ $ 42,150 Operating cash flows from finance leases ​ ​ 13,316 Financing cash flows from finance leases ​ ​ 25,275 Right-of-use assets obtained in exchange for lease obligations ​ ​ ​ Operating leases ​ ​ 38,143 Finance leases ​ ​ 50,484 ​ Other information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ ​ 2020 2019 ​ ​ (in thousands) Finance leases included in property and equipment ​ ​ ​ ​ ​ ​ Property and equipment ​ $ 171,380 ​ $ 134,931 Accumulated depreciation ​ ​ (41,737) ​ ​ (27,686) Property and equipment, net ​ $ 129,643 ​ $ 107,245 Weighted-average remaining lease term (years) ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 4.9 ​ ​ ​ Finance leases ​ ​ 3.6 ​ ​ ​ Weighted-average discount rate ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 5.5 % ​ ​ Finance leases ​ ​ 5.0 % ​ ​ ​ Future minimum lease payments under non-cancellable leases as of April 30, 2020 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance Operating Year Ending April 30, ​ (in thousands) 2021 ​ $ 46,116 ​ $ 38,960 2022 ​ 39,328 ​ 30,387 2023 ​ 30,525 ​ 23,655 2024 ​ 21,234 ​ 18,775 2025 ​ 10,544 ​ 12,154 Thereafter ​ 3,647 ​ 16,848 Total lease payments ​ ​ 151,394 ​ ​ 140,779 Less imputed interest ​ 22,627 ​ 18,134 Total ​ $ 128,767 ​ $ 122,645 ​

Retirement Plan

Retirement Plan	12 Months Ended
	Apr. 30, 2020
Retirement Plan
Retirement Plan	9. Retirement Plan The Company maintains a 401(k) defined contribution retirement plan for its employees. Participants are allowed to choose from a selection of mutual funds in order to designate how both employer and employee contributions are invested. Under the plan, the Company matches 50% of each employee’s contributions on the first 4% of the employee’s compensation contributed. The Company contributed $5.3 million, $4.7 million and $4.3 million, during the years ended April 30, 2020, 2019 and 2018, respectively. In June 2020, the Company temporarily suspended matching contributions under the plan. ​

Income Taxes

Income Taxes	12 Months Ended
	Apr. 30, 2020
Income Taxes
Income Taxes	10. Income Taxes The following table presents the components of income before taxes for the years ended April 30, 2020, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 2018 ​ ​ (in thousands) United States ​ $ 106,850 ​ $ 62,878 ​ $ 83,854 Foreign ​ ​ (60,525) ​ ​ 7,163 ​ ​ — Income before taxes ​ $ 46,325 ​ $ 70,041 ​ $ 83,854 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 2018 ​ ​ (in thousands) Current ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 12,537 ​ $ 11,858 ​ $ 30,827 Foreign ​ ​ 1,624 ​ ​ 13,739 ​ ​ — State ​ 7,857 ​ 5,929 ​ 6,409 Total current ​ 22,018 ​ 31,526 ​ 37,236 Deferred ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ 8,986 ​ 453 ​ (14,796) Foreign ​ ​ (7,347) ​ ​ (16,931) ​ ​ — State ​ (713) ​ (1,009) ​ (1,557) Total deferred ​ 926 ​ (17,487) ​ (16,353) Total provision for income taxes ​ $ 22,944 ​ $ 14,039 ​ $ 20,883 ​ The following table summarizes the significant differences between the U.S. federal statutory tax rate and the Company’s effective tax rate for financial statement for the years ended April 30, 2020, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 2018 ​ ​ (in thousands) Federal income taxes at statutory rate ​ $ 9,747 ​ $ 14,715 ​ $ 25,492 State income taxes, net of federal income tax benefit ​ 4,054 ​ 2,440 ​ 1,900 Impact of foreign rate differences ​ ​ (2,861) ​ ​ 418 ​ ​ — Impact of rate difference on impairment of goodwill ​ ​ 7,630 ​ ​ — ​ ​ — Net change in valuation allowance ​ 9,070 ​ 664 ​ 151 Nondeductible meals & entertainment ​ 592 ​ 635 ​ 822 Equity-based compensation ​ ​ (1,196) ​ ​ (53) ​ ​ — GILTI ​ ​ 704 ​ ​ 241 ​ ​ — Nondeductible transaction costs ​ 90 ​ 529 ​ 2 Net deferred benefit due to Tax Cuts and Jobs Act ​ ​ — ​ ​ — ​ ​ (6,763) Intercompany interest expense ​ ​ (5,361) ​ ​ (5,255) ​ ​ — Other ​ 475 ​ (295) ​ (721) Total provision for income taxes ​ $ 22,944 ​ $ 14,039 ​ $ 20,883 ​ The tax effects of temporary differences, which give rise to deferred income taxes as of April 30, 2020 and 2019 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 Deferred income tax assets: ​ (in thousands) Allowances on accounts and notes receivable ​ $ 2,016 ​ $ 2,306 Accrued payroll and related costs ​ 1,859 ​ 1,577 Insurance reserves ​ 2,501 ​ 1,746 Inventory costs ​ 2,630 ​ 2,066 Deferred compensation ​ ​ 7,426 ​ ​ 6,854 Equity compensation ​ 2,695 ​ 2,944 Derivative instrument ​ 7,850 ​ 1,358 Acquisition related costs ​ 1,311 ​ 1,779 Net operating loss carry-forwards ​ 1,595 ​ 1,745 Disallowed interest expense ​ ​ 736 ​ ​ 2,507 Investment in partnerships ​ ​ 16,535 ​ ​ 4,676 Deferred rent ​ 1,112 ​ 604 Noncompete agreements ​ 120 ​ 133 Other deferred tax assets, net ​ 1,424 ​ 1,394 Total deferred income tax assets ​ 49,810 ​ 31,689 Less: Valuation allowance ​ (10,183) ​ (1,112) Total deferred income tax assets, net of valuation allowance ​ 39,627 ​ 30,577 Deferred income tax liabilities: ​ ​ ​ ​ ​ ​ Amortization of intangible assets ​ (18,917) ​ (22,950) Rebates ​ ​ (400) ​ ​ (72) Depreciation ​ (21,508) ​ (10,495) Deferred financing costs ​ (1,582) ​ (2,075) Other deferred tax liabilities, net ​ (334) ​ ​ (535) Total deferred income tax liabilities ​ (42,741) ​ (36,127) Deferred income tax liabilities, net ​ $ (3,114) ​ $ (5,550) ​ Tax Cuts and Job Act. ​ As of April 30, 2018, the Company was still assessing the overall impact of the Tax Act on its financial statements and had not completed its accounting for the tax effects of the Tax Act. The Company reported provisional amounts reflecting reasonable estimates for the re-measurement of net deferred tax liabilities as of April 30, 2018 due to the reduction in the corporate rate. The Company recorded a provisional income tax benefit of $6.7 million for this re-measurement for the year ended April 30, 2018, which is included in provision for income taxes in the Consolidated Statements of Operations and Comprehensive Income (Loss). This represented a $1.1 million decrease from the provisional amount recorded during the nine months ended January 31, 2018. During the year ended April 30, 2019, the Company completed its analysis to determine the effects of the Tax Act. As a result, the Company recorded a $0.1 million income tax benefit during the year ended April 30, 2019 related to tax adjustments made in accordance with SAB 118 with respect to the adjustment of its original provisional estimate of the impact of the Tax Act. ​ The Company is subject to provisions of the Tax Act related to current tax on global intangible low-taxed income (“GILTI”) earned by certain foreign subsidiaries. The FASB Staff Q&A, Topic 740 No. 5, Accounting for Global Intangible Low-Taxed Income, states that an entity can make an accounting policy election to either recognize deferred taxes for temporary differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred. The Company has elected to recognize the tax on GILTI as a period expense in the period the tax is incurred. ​ As of April 30, 2020, the Company’s assertion has not changed from the year ended April 30, 2019 and does not intend to permanently reinvest its accumulated earnings in its non-U.S. subsidiaries and will continue to periodically distribute the earnings on an as needed basis. The Company had no unremitted earnings in the current year. To the extent there are unremitted earnings in future years, the Company does not anticipate significant tax consequences as there is sufficient paid up capital in Canada to return the cash free of withholding taxes. ​ Effective tax rate. ​ NOLs Valuation allowance. Management makes an assessment to determine if its deferred tax assets are more likely than not to be realized. Valuation allowances are established if management believes that it is more likely than not the related tax benefits will not be realized. The valuation allowance as of April 30, 2020 and 2019 was $10.2 million and $1.1 million, respectively. During the year ended April 30, 2020, the Company recorded $7.6 million of valuation allowance related to a portion of the Titan outside basis difference that was created as a result of the impairment of goodwill recognized during the year ended April 30, 2020. The remaining valuation allowance as of April 30, 2020 and 2019 primarily relates to state net operating loss carry forwards. Uncertain tax positions. As of April 30, 2020, the tax years ended April 30, 2020, 2019, 2018 and 2017 remain subject to examination by the U.S. Internal Revenue Service. In states in which the Company conducts business, the statute of limitation periods for examination generally vary from three

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Apr. 30, 2020
Stockholders' Equity
Stockholders' Equity	11. Stockholders’ Equity ​ Exchangeable Shares ​ In connection with the acquisition of Titan on June 1, 2018, the Company issued 1.1 million Exchangeable Shares. The Exchangeable Shares were issued by an indirect wholly owned subsidiary of the Company. The Exchangeable Shares ranked senior to the Company’s common stock with respect to dividend rights and rights on liquidation, dissolution and winding-up. The holders of the Exchangeable Shares were entitled to receive dividends or distributions that are equal to any dividends or distributions on the Company’s common stock. The holders of the Exchangeable Shares did not have voting rights. ​ The Exchangeable Shares contained rights that allow the holders to exchange their Exchangeable Shares for GMS common stock at any time on a one-for- one basis. If converted, the holders were prevented from transferring such GMS common stock for one year from the Titan acquisition date. On June 13, 2019, the holders of the Exchangeable Shares exchanged all of the Exchangeable Shares for 1.1 million shares of the Company’s common stock. Following such exchange, the Exchangeable Shares ceased to be outstanding. ​ Share Repurchase Program ​ On November 30, 2018, the Company’s Board of Directors authorized a common stock repurchase program to repurchase up to $75.0 million outstanding common stock. The Company may conduct repurchases under the share repurchase program through open market transactions, under trading plans in accordance with SEC Rule 10b5-1 and/or in privately negotiated transactions, in compliance with Rule 10b-18 under the Exchange Act of 1934, as amended, subject to a variety of factors, including, but not limited to, our liquidity, credit availability, general business and market conditions, our debt covenant restrictions and the availability of alternative investment opportunities. ​ The Company did not repurchase any shares of its common stock during the year ended April 30, 2020. The Company repurchased 1.0 million shares of its common stock for $16.5 million during the year ended April 30, 2019 pursuant to its share repurchase program. The repurchased common stock was retired. As of April 30, 2020, the Company had $58.5 million remaining under . ​ Secondary Public Offering ​ On September 9, 2019, AEA Investors LP and its affiliates (“AEA”) completed a secondary public offering of 6.8 million shares of the Company’s common stock at a price to the public of $27.20 per share, representing all of AEA’s remaining ownership in the Company. The Company did not receive any proceeds from the sale of its common stock in the offering by AEA. As a result of the offering, AEA no longer has the right to nominate any directors to the Company’s board of directors pursuant to the Company stockholders’ agreement. ​ Accumulated Other Comprehensive Income (Loss) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ Foreign ​ Derivative ​ Other ​ ​ Currency ​ Financial ​ Comprehensive ​ ​ Translation ​ Instruments ​ Income (Loss) ​ ​ (in thousands) Balance as of April 30, 2017 ​ $ — ​ $ (884) ​ $ (884) Other comprehensive income before reclassification ​ ​ — ​ ​ 309 ​ 309 Reclassification to earnings from accumulated other comprehensive (loss) income ​ ​ — ​ ​ 1,016 ​ 1,016 Balance as of April 30, 2018 ​ ​ — ​ ​ 441 ​ ​ 441 Other comprehensive loss before reclassification ​ ​ (22,320) ​ ​ (5,423) ​ ​ (27,743) Reclassification to earnings from accumulated other comprehensive (loss) income ​ ​ — ​ ​ 728 ​ ​ 728 Balance as of April 30, 2019 ​ ​ (22,320) ​ ​ (4,254) ​ ​ (26,574) Other comprehensive loss before reclassification ​ ​ (18,257) ​ ​ (20,251) ​ ​ (38,508) Reclassification to earnings from accumulated other comprehensive (loss) income ​ ​ — ​ ​ — ​ ​ — Balance as of April 30, 2020 ​ $ (40,577) ​ $ (24,505) ​ $ (65,082) ​

Equity-Based Compensation

Equity-Based Compensation	12 Months Ended
	Apr. 30, 2020
Equity-Based Compensation
Equity-Based Compensation	12. Equity-Based Compensation General The Company has granted options and restricted stock units to employees and non-employee directors to purchase the Company’s common stock under various stock incentive plans. Stock options are granted with an exercise price equal to the closing market value of GMS common stock on the date of grant, have a term of ten years , and vest over terms of three to four years from the date of grant. Restricted stock units are granted with various vesting terms that range from one to three years from the date of grant. The Company intends to use authorized and unissued shares to satisfy share award exercises. ​ Share-based compensation expense related to stock options and restricted stock units was $6.5 million, $3.6 million and $1.7 million during the years ended April 30, 2020, 2019 and 2018, respectively, and is included in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). ​ Stock Option Awards ​ The following table presents stock option activity as of and for the year ended April 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ Number of ​ Exercise ​ Contractual ​ Intrinsic ​ ​ Options ​ Price ​ Life (years) ​ Value ​ ​ (shares and dollars in thousands) Outstanding as of April 30, 2019 2,080 ​ $ 16.34 6.15 ​ $ 7,615 Options granted 386 ​ ​ 21.63 ​ Options exercised (874) ​ 13.22 ​ Options forfeited (105) ​ 25.73 ​ Options expired — ​ — ​ ​ Outstanding as of April 30, 2020 1,487 ​ $ 18.85 6.40 ​ $ 3,895 Exercisable as of April 30, 2020 941 ​ $ 16.32 4.98 ​ $ 3,866 Vested and expected to vest as of April 30, 2020 1,481 ​ $ 18.83 6.39 ​ $ 3,895 ​ The aggregate intrinsic value represents the value of the Company’s closing stock price on the last trading day of the period in excess of the weighted average exercise price multiplied by the number of options outstanding, exercisable or expected to vest. Options expected to vest are unvested shares net of expected forfeitures. The total intrinsic value of options exercised during the years ended was $11.5 million, $1.6 million and $4.3 million, respectively. ​ The fair value of stock options granted during the years ended April 30, 2020, 2019 and 2018 was estimated using the Black-Scholes option-pricing model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 ​ 2019 ​ 2018 Volatility ​ 49.86 % ​ 33.71 % 30.86 % Expected life (years) ​ 6.0 ​ ​ 6.0 ​ 6.0 ​ Risk-free interest rate ​ 1.97 % ​ 2.87 % 2.18 % Dividend yield ​ — % ​ — % — % ​ The weighted average grant date fair value of options granted during the years ended April 30, 2020, 2019 and 2018 was $10.59 per share, $9.72 per share and $12.81 per share, respectively. The expected volatility was based on historical and implied volatility. The expected life of stock options was based on previous history of exercises. The risk-free rate was based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the stock option. The expected dividend yield was 0% as we have not declared any common stock dividends to date and do not expect to declare common stock dividends in the near future. The fair value of the underlying common stock at the date of grant was determined based on the value of the Company’s closing stock price on the trading day immediately preceding the date of the grant. ​ Restricted Stock Units ​ The following table presents restricted stock unit activity for the year ended April 30, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of ​ Average ​ ​ Restricted ​ Exercise ​ ​ Stock Units ​ Price ​ ​ (shares in thousands) Outstanding as of April 30, 2019 ​ 193 ​ $ 25.48 Granted ​ 233 ​ ​ 21.67 Vested ​ (100) ​ ​ 24.48 Forfeited ​ (40) ​ ​ 25.29 Outstanding as of April 30, 2020 ​ 286 ​ $ 22.71 ​ As of April 30, 2020, there was $3.8 million of total unrecognized compensation cost related to nonvested restricted stock units. That cost is expected to be recognized over a weighted-average period of 1.8 years . Employee Stock Purchase Plan During the year ended April 30, 2018, the Company established an employee stock purchase plan (“ESPP”), the terms of which allow for qualified employees (as defined) to participate in the purchase of shares of the Company’s common stock at a price equal to 90% of the lower of the closing price at the beginning or end of the last day of the purchase period, which is a six-month period ending on December 31 and June 30 of each year. authorizes the issuance of a total During the years ended April 30, 2020 and 2019, 0.1 million and 0.1 million shares, respectively, of the Company’s common stock were purchased under the ESPP at an average price of $15.62 per share and $18.51 per shares, respectively. The Company recognized $0.5 million, $0.3 million and $0.1 million of stock-based compensation expense in during the years ended April 30, 2020, 2019 and 2018, respectively, related to the ESPP.

Stock Appreciation Rights, Defe

Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests	12 Months Ended
	Apr. 30, 2020
Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests
Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests	13. Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests The following table presents a summary of changes to the liabilities for stock appreciation rights, deferred compensation and redeemable noncontrolling interests for the years ended April 30, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock ​ ​ ​ ​ Redeemable ​ ​ Appreciation ​ Deferred ​ Noncontrolling ​ ​ Rights ​ Compensation ​ Interests ​ ​ (in thousands) Balance as of April 30, 2018 ​ $ 21,944 ​ $ 2,222 $ 16,170 Amounts redeemed ​ ​ (1,216) ​ ​ (715) ​ ​ (4,673) Change in fair value ​ 2,730 ​ 188 ​ 1,001 Balance as of April 30, 2019 ​ ​ 23,458 ​ ​ 1,695 ​ ​ 12,498 Amounts redeemed ​ (825) ​ (108) ​ (4,644) Change in fair value ​ 1,572 ​ 73 ​ 446 Balance as of April 30, 2020 ​ $ 24,205 ​ $ 1,660 ​ $ 8,300 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of April 30, 2019 ​ $ 1,355 ​ $ 108 ​ $ 1,569 Classified as long-term as of April 30, 2019 ​ ​ 22,103 ​ ​ 1,587 ​ ​ 10,929 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of April 30, 2020 ​ $ 624 ​ $ — ​ $ — Classified as long-term as of April 30, 2020 ​ ​ 23,581 ​ ​ 1,660 ​ ​ 8,300 ​ Total expense related to these instruments was $2.1 million, $3.9 million and $4.0 million during the years ended April 30, 2020, 2019 and 2018, respectively, and was included in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). Stock Appreciation Rights Deferred Compensation Redeemable Noncontrolling Interests Upon the termination of employment or other triggering events including death or disability of the noncontrolling stockholders in the Company’s subsidiaries, we are obligated to purchase, or redeem, the noncontrolling interests at either an agreed upon price or a formula value provided in the stockholder agreements. This formula value is typically based on the book value per share of the subsidiary’s equity, including certain adjustments.

Derivative Instruments

Derivative Instruments	12 Months Ended
	Apr. 30, 2020
Derivative Instruments
Derivative Instruments	14. Derivative Instruments ​ Interest Rate Swap ​ In February 2019, the Company entered into interest rate swap agreements with a notional amount of $500.0 million to convert the variable interest rate on a portion of its Term Loan Facility to a fixed 1-month LIBOR interest rate . The contracts were effective on and terminate on ​ Foreign Currency Forward Contract ​ In April 2018, in connection with the acquisition of Titan (see Note 3, “Business Acquisitions”), the Company entered into a foreign currency forward contract to mitigate the foreign currency exchange risk associated with the purchase price that was denominated in Canadian dollars. The foreign currency forward contract effectively fixed the amount the Company paid for the purchase price denominated in Canadian dollars by contracting the Company to pay U.S. dollars and receive Canadian dollars on the notional amount. ​ During the year ended April 30, 2018, the Company recognized a $5.1 million loss on the change in fair value of a foreign currency forward contract. During the year ended April 30, 2019, the Company recognized a $5.7 million loss on the change in fair value of its foreign currency forward contract, which was settled upon the acquisition on Titan on June 1, 2018. The losses are included within change in fair value of financial instruments in the Consolidated Statements of Operations and Comprehensive Income (Loss).

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Apr. 30, 2020
Fair Value Measurements
Fair Value Measurements	15. Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Recurring Basis the estimated carrying amount and fair value of the Company’s liabilities measured at fair value on a recurring basis ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ ​ 2020 ​ 2019 ​ ​ (in thousands) Interest rate swaps (Level 2) ​ $ 32,218 ​ $ 5,613 Stock appreciation rights (Level 3) ​ ​ 24,205 ​ ​ 23,458 Deferred compensation (Level 3) ​ ​ 1,660 ​ 1,695 Noncontrolling interest holders (Level 3) ​ ​ 8,300 ​ ​ 12,498 Contingent consideration (Level 3) ​ ​ — ​ 12,354 ​ Derivative instruments the Company ​ Stock appreciation rights, deferred compensation and redeemable noncontrolling interests Contingent consideration Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis ​ Disclosures are required for certain assets and liabilities that are measured at fair value on a nonrecurring basis in periods to initial recognition. Such measurements of fair value relate primarily to assets and liabilities measured at fair value in connection with business combinations and asset impairments. For more information on business combinations, see Note 3, “Business Acquisitions.” a $63.1 million non-cash impairment charge to goodwill related to its Canada reporting unit. See Note 5, “Goodwill and Intangible Assets,” for more information regarding the impairment of goodwill and the fair value methodology. Also during the fourth quarter of 2020, the Company initiated a restructuring plan to close one of its facilities and recorded a $1.9 million impairment of the operating lease right-of-use asset. There were no other material long-lived asset impairments during the years ended April 30, 2020, 2019 or 2018 .

Transactions With Related Parti

Transactions With Related Parties	12 Months Ended
	Apr. 30, 2020
Transactions With Related Parties
Transactions With Related Parties	16. Transactions With Related Parties The Company leases warehouse facilities from partnerships owned by certain stockholders of GMS Inc. and its subsidiaries. As of April 30, 2020, these leases had expiration dates through fiscal 2025. Rent expense related to these leases was $0.8 million, $0.8 million and $0.8 million during the years ended April 30, 2020, 2019 and 2018, respectively, and are included in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). As of April 30, 2020, future minimum payments under the terms of the leases aggregated to $1.2 million. The Company purchases inventories from Southern Wall Products, Inc. (“SWP”) on a continuing basis. Certain stockholders of the Company are stockholders of SWP. The Company purchased inventory from SWP for distribution in the amount of $14.3 million, $13.3 million and $14.0 million during the years ended April 30, 2020, 2019 and 2018, respectively. Amounts due to SWP for purchases of inventory for distribution as of April 30, 2020 and 2019 were $1.2 million and $1.2 million, respectively, and are included in accounts payable in the Consolidated Balance Sheets.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Apr. 30, 2020
Commitments and Contingencies
Commitments and Contingencies	17. Commitments and Contingencies General ​ The Company is a defendant in various lawsuits and administrative actions associated with personal injuries, claims of former employees, and other events arising in the normal course of business. As discussed in Note 1, “Business, Basis of Presentation and Summary of Significant Accounting Policies” under the heading “Insurance Liabilities,” the Company records liabilities for these claims, as well as assets for amounts recoverable from the insurer, for these claims covered by insurance. ​ Favorable Class Action Settlement ​ In February 2020, the Company received proceeds as part of a class action settlement against certain drywall manufacturers related to purchases made during calendar years 2012 and 2013. The Company recorded a gain on legal settlement of $14.0 million during the year ended April 30, 2020.

Segments

Segments	12 Months Ended
	Apr. 30, 2020
Segments
Segments	18. Segments General The Company has seven operating segments based on geographic operations that it aggregates into one reportable segment. The Company defines operating segments as components of the organization for which discrete financial information is available and operating results are evaluated on a regular basis by the (“CODM”) in order to assess performance and allocate resources The Company determined it has seven operating segments based on the Company’s seven geographic divisions, which are Central, Midwest, Northeast, Southern, Southeast, Western and Canada. The Company aggregates its operating segments into a single reportable segment based on similarities between the operating segments’ economic characteristics, nature of products sold, production process, type of customer and methods of distribution. The accounting policies of the operating segments are the same as those described in the summary of significant policies. In addition to the Company’s reportable segment, the Company’s consolidated results include both corporate activities and certain other activities. Corporate includes the Company’s corporate office building and support services provided to its subsidiaries. Other includes Tool Source Warehouse, Inc., which functions primarily as an internal distributor of tools. Segment Results The CODM assesses the Company’s performance based on the periodic review of net sales, Adjusted EBITDA and certain other measures for each of the operating segments. In addition, the Company utilizes Adjusted EBITDA in certain calculations under the ABL Facility and the Term Loan Facility. The ABL Facility and the Term Loan Facility permit the Company to make certain additional adjustments in calculating Consolidated EBITDA, such as projected net cost savings, which are not reflected in the Adjusted EBITDA data presented in this Annual Report on Form 10-K. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations -- Non-GAAP Financial Measures” for a further discussion of this non-GAAP measure. The following tables present segment results ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2020 ​ ​ ​ ​ April 30, 2020 ​ ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ Total ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ Assets ​ ​ (in thousands) Geographic divisions ​ $ 3,213,938 ​ $ 1,053,555 ​ $ 114,279 ​ $ 297,646 ​ $ 2,264,208 Other ​ 27,369 ​ 9,659 ​ 233 ​ 2,113 ​ 18,745 Corporate ​ — ​ — ​ 2,021 ​ — ​ 5,829 ​ ​ $ 3,241,307 ​ $ 1,063,214 ​ $ 116,533 ​ $ 299,759 ​ $ 2,288,782 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2019 ​ ​ ​ ​ April 30, 2019 ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ Total ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ Assets ​ ​ (in thousands) Geographic divisions ​ $ 3,090,314 ​ $ 994,981 ​ $ 114,558 ​ $ 293,190 ​ $ 2,125,518 Other ​ 25,718 ​ 9,138 ​ 220 ​ 2,479 ​ 16,897 Corporate ​ — ​ — ​ 2,681 ​ — ​ 7,139 ​ ​ $ 3,116,032 ​ $ 1,004,119 ​ $ 117,459 ​ $ 295,669 ​ $ 2,149,554 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2018 ​ ​ ​ ​ April 30, 2018 ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ Total ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ Assets ​ ​ (in thousands) Geographic divisions ​ $ 2,487,557 ​ $ 809,884 ​ $ 64,491 ​ $ 196,903 ​ $ 1,434,371 Other ​ 23,912 ​ 8,692 ​ 242 ​ 2,355 ​ 12,854 Corporate ​ — ​ — ​ 797 ​ — ​ 7,286 ​ ​ $ 2,511,469 ​ $ 818,576 ​ $ 65,530 ​ $ 199,258 ​ $ 1,454,511 ​ The following table presents a reconciliation of net income to Adjusted EBITDA for the years ended April 30, 2020, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 2019 2018 ​ ​ (in thousands) Net income ​ $ 23,381 ​ $ 56,002 ​ $ 62,971 Interest expense ​ 67,718 ​ ​ 73,677 ​ ​ 31,395 Write-off of debt discount and deferred financing fees ​ ​ 1,331 ​ ​ — ​ ​ 74 Interest income ​ (88) ​ ​ (66) ​ ​ (177) Provision for income taxes ​ 22,944 ​ ​ 14,039 ​ ​ 20,883 Depreciation expense ​ 51,332 ​ ​ 46,456 ​ ​ 24,075 Amortization expense ​ 65,201 ​ ​ 71,003 ​ ​ 41,455 Impairment of goodwill ​ ​ 63,074 ​ ​ — ​ ​ — Stock appreciation expense(a) ​ ​ 1,572 ​ ​ 2,730 ​ ​ 2,318 Redeemable noncontrolling interests(b) ​ 520 ​ ​ 1,188 ​ ​ 1,868 Equity-based compensation(c) ​ 7,060 ​ ​ 3,906 ​ ​ 1,695 Severance and other permitted costs(d) ​ 5,733 ​ ​ 8,152 ​ ​ 581 Transaction costs (acquisitions and other)(e) ​ 2,414 ​ ​ 7,858 ​ ​ 3,370 Loss (gain) on disposal and impairment of assets(f) ​ 658 ​ ​ (525) ​ ​ (509) Effects of fair value adjustments to inventory(g) ​ 575 ​ ​ 4,176 ​ ​ 324 Change in fair value of financial instruments(h) ​ — ​ ​ 6,395 ​ ​ 6,125 Gain on legal settlement ​ ​ (14,029) ​ ​ — ​ ​ — Secondary public offering costs(i) ​ ​ 363 ​ ​ — ​ ​ 1,525 Debt transaction costs(j) ​ ​ — ​ ​ 678 ​ ​ 1,285 Adjusted EBITDA ​ $ 299,759 ​ $ 295,669 ​ $ 199,258 (a) Represents non-cash expense related to stock appreciation rights agreements. (b) Represents non-cash compensation expense related to changes in the fair values of noncontrolling interests . (c) Represents non-cash equity-based compensation expense related to the issuance of share-based awards. (d) Represents severance expenses and other costs permitted in calculations under the ABL Facility and the Term Loan Facility, including certain unusual, nonrecurring costs due to COVID-19. (e) Represents costs related to acquisitions paid to third parties. (f) The year ended April 30, 2020 includes a $1.9 million impairment of operating lease right-of-use assets resulting from a restructuring plan to close one of the Company’s facilities. (g) Represents the non-cash cost of sales impact of purchase accounting adjustments to increase inventory to its estimated fair value. (h) Represents the mark-to-market adjustments for derivative financial instruments. (i) Represents costs paid to third-party advisors related to secondary offerings of our common stock. (j) Represents costs paid to third-party advisors related to debt refinancing activities. ​ ​ Revenues by Product The following table presents Company’s net sales to external customers by main product line for the years ended April 30, 2020, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 ​ 2019 ​ 2018 ​ ​ (in thousands) Wallboard ​ $ 1,329,775 $ 1,272,068 $ 1,109,552 Ceilings ​ 475,827 451,695 387,360 Steel framing ​ 502,122 506,805 411,630 Other products ​ 933,583 885,464 602,927 Total net sales ​ $ 3,241,307 $ 3,116,032 $ 2,511,469 ​ Geographic Information The following table presents the Company’s net sales by major geographic area for the years ended April 30, 2020, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 ​ 2019 ​ ​ (in thousands) United States ​ $ 2,805,920 $ 2,701,678 $ 2,511,469 Canada ​ 435,387 414,354 — Total net sales ​ $ 3,241,307 $ 3,116,032 ​ $ 2,511,469 ​ The following table presents the Company’s property and equipment by major geographic area ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ April 30, ​ 2020 2019 ​ ​ (in thousands) United States ​ $ 270,855 ​ $ 249,857 Canada ​ 34,612 32,492 Total property and equipment, net ​ $ 305,467 $ 282,349 ​

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Apr. 30, 2020
Earnings Per Common Share
Earnings Per Common Share	19. Earnings Per Common Share The following table sets forth the computation of basic and diluted earnings per share of common stock for the years ended April 30, 2020, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 2019 2018 ​ ​ (in thousands, except per share data) Net income ​ $ 23,381 ​ $ 56,002 ​ $ 62,971 Less: Net income allocated to participating securities ​ ​ 74 ​ ​ 1,382 ​ ​ — Net income attributable to common stockholders ​ $ 23,307 $ 54,620 ​ $ 62,971 Basic earnings per common share: ​ ​ ​ ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 41,853 ​ 40,914 ​ 41,015 Basic earnings per common share ​ $ 0.56 ​ $ 1.33 ​ $ 1.54 Diluted earnings per common share: ​ ​ ​ Basic weighted average common shares outstanding ​ 41,853 ​ 40,914 ​ 41,015 Add: Common Stock Equivalents ​ 651 ​ 675 ​ 1,148 Diluted weighted average common shares outstanding ​ 42,504 ​ 41,589 ​ 42,163 Diluted earnings per common share ​ $ 0.55 ​ $ 1.31 ​ $ 1.49 ​ During the years ended April 30, 2020 and 2019, approximately 0.8 million and 0.6 million, respectively, stock options and restricted stock units were excluded from the calculation of diluted earnings per share because their effect would have been anti-dilutive. Anti-dilutive securities could be dilutive in future periods.

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Apr. 30, 2020
Valuation and Qualifying Accounts
Valuation and Qualifying Accounts	20. Valuation and Qualifying Accounts Allowances for Accounts Receivable ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance ​ ​ Charged to ​ ​ Balance ​ ​ at Beginning ​ ​ ​ ​ Other ​ ​ ​ ​ at End of ​ ​ of Period ​ Provision ​ Accounts(a) ​ Deductions ​ Period ​ ​ (in thousands) Fiscal Year Ended April 30, 2020 ​ $ (6,432) ​ $ (2,348) ​ $ 938 ​ $ 2,701 ​ $ (5,141) Fiscal Year Ended April 30, 2019 ​ ​ (9,633) ​ ​ (1,064) ​ ​ 2,435 ​ ​ 1,830 ​ ​ (6,432) Fiscal Year Ended April 30, 2018 ​ (9,851) ​ (366) ​ (596) ​ 1,180 ​ (9,633) (a) Charged to other accounts represents the net (increase) decrease for specifically reserved accounts, as well as the net change in reserves for sales discounts, service charges and sales returns. The adoption of the new revenue recognition guidance on May 1, 2018 resulted in a $3.6 million reclassification in the Consolidated Balance Sheet from trade accounts and notes receivable to other accrued expenses and current liabilities for estimated sales returns. This reclass is reflected in charged to other accounts for the fiscal year ended April 30, 2019. ​ Valuation Allowance on Deferred Tax Assets Rollforward ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance Additions ​ Balance ​ ​ at Beginning ​ Charged to Costs ​ ​ ​ at End of ​ ​ of Period ​ and Expenses ​ Deductions ​ Period ​ ​ (in thousands) Fiscal Year Ended April 30, 2020 ​ $ (1,112) ​ $ (9,071) ​ $ — ​ $ (10,183) Fiscal Year Ended April 30, 2019 ​ ​ (448) ​ ​ (664) ​ ​ — ​ ​ (1,112) Fiscal Year Ended April 30, 2018 ​ (297) ​ (151) ​ — ​ (448) ​

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Apr. 30, 2020
Selected Quarterly Financial Data (Unaudited)
Selected Quarterly Financial Data (Unaudited)	​ 21. Selected Quarterly Financial Data (Unaudited) The following table sets forth certain unaudited financial information for each quarter of the years ended April 30, 2020 and 2019. The unaudited quarterly information includes all adjustments (consisting of normal recurring adjustments) that, in the opinion of management, are necessary for the fair presentation of the information presented. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2020 ​ First Second Third Fourth ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ ​ (in thousands, except per share data) Net sales ​ $ 847,176 ​ $ 861,929 ​ $ 761,352 ​ $ 770,850 Gross profit ​ 273,654 ​ 284,493 ​ 253,473 ​ 251,594 Net income (loss)(1) ​ 24,820 ​ 29,138 ​ 10,879 ​ (41,456) Per share data ​ ​ ​ ​ Weighted average shares outstanding(2): ​ ​ ​ ​ Basic ​ 41,001 ​ 41,761 ​ 42,223 ​ 42,435 Diluted ​ 41,615 ​ 42,635 ​ 42,949 ​ 42,435 Net income (loss) per share(2): ​ ​ ​ ​ Basic ​ $ 0.60 ​ $ 0.70 ​ $ 0.26 ​ $ (0.98) Diluted ​ $ 0.59 ​ $ 0.68 ​ $ 0.25 ​ $ (0.98) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2019 ​ First Second Third Fourth ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ ​ (in thousands, except per share data) Net sales ​ $ 778,144 ​ $ 833,837 ​ $ 723,902 ​ $ 780,149 Gross profit ​ 244,816 ​ 268,150 ​ 234,226 ​ 256,927 Net income(3) ​ 8,650 ​ 24,912 ​ 5,815 ​ 16,625 Per share data ​ ​ ​ ​ Weighted average shares outstanding(2): ​ ​ ​ ​ Basic ​ 41,094 ​ 41,149 ​ 40,912 ​ 40,487 Diluted ​ 42,074 ​ 41,918 ​ 41,371 ​ 40,976 Net income per share(2): ​ ​ ​ ​ Basic ​ $ 0.21 ​ $ 0.59 ​ $ 0.14 ​ $ 0.40 Diluted ​ $ 0.20 ​ $ 0.58 ​ $ 0.14 ​ $ 0.39 (1) Net income for the fourth quarter of 2020 includes a $63.1 million non-cash impairment charge to goodwill and a $14.0 million gain on legal settlement. In February 2020, the Company received proceeds as part of a class action settlement. ​ (2) Basic and diluted net income per share are computed independently for each of the quarters presented. Therefore, the sum of the quarterly basic and diluted net income per share amounts may not equal annual basic and diluted net income per share amounts. ​ (3) Net income for the first quarter of 2019 includes a $5.7 million loss on change in fair value of financial instruments related to the Company’s foreign currency forward contract.

Business, Basis of Presentati_2

Business, Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Apr. 30, 2020
Business, Basis of Presentation and Summary of Significant Accounting Policies
Principles of Consolidation	Principles of Consolidation The consolidated financial statements of the Company include the accounts of its wholly owned subsidiaries. All material intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Foreign Currency Translation	Foreign Currency Translation Assets and liabilities of the Company’s Canadian subsidiaries are translated at the exchange rate prevailing at the balance sheet date, while income and expenses are translated at average rates for the period. Translation gains and losses are reported as a separate component of stockholders’ equity and other comprehensive income (loss). Gains and losses on foreign currency transactions are recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) within other income, net.
Reclassifications	Reclassifications ​ Certain amounts in the prior year financial statements have been reclassified to conform to the current year presentation.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents.
Trade Accounts Receivable	Trade Accounts Receivable Accounts receivables are recorded at their net realizable value. The Company maintains an allowance for doubtful accounts for estimated losses due to the failure of customers to make required payments, as well as allowances for cash discounts. The Company’s estimate of the allowance for doubtful accounts is based on an assessment of individual past due accounts, historical write-off experience, accounts receivable aging and current economic trends. Account balances are written off when the potential for recovery is considered remote.
Inventories	Inventories ​ Inventories consist of finished goods purchased for resale and include wallboard, ceilings, steel framing and other specialty building products. Inventories are valued at the lower of cost or market (net realizable value). The cost of inventories is determined by the moving average cost method. The Company routinely evaluates inventory for excess or obsolescence and considers factors such as historical usage rates and demand. ​
Property and Equipment	Property and Equipment Property and equipment is recorded at cost less accumulated depreciation. Property and equipment obtained through acquisition is stated at estimated fair value as of the acquisition date. Expenditures for improvements and betterments are capitalized, while the costs of maintenance and repairs are charged to operating expense as incurred. Gains and losses related to the sale of property and equipment are recorded in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). Depreciation expense for property and equipment of U.S. subsidiaries is determined using the straight-line method over the estimated useful lives of the various asset classes. The estimated useful lives of property and equipment are as follows: ​ ​ ​ ​ Buildings 25 - 39 years Furniture, fixtures and automobiles 3 - 5 years Warehouse and delivery equipment 4 - 10 years Leasehold improvements Shorter of estimated useful life or lease term ​ Depreciation expense for property and equipment of Canadian subsidiaries is recognized over the estimated useful lives of the various asset classes as follows: ​ ​ ​ ​ Vehicles and trucks 30% - 40% declining balance Furniture and fixtures 8% - 20% declining balance Buildings 4% declining balance Machinery and equipment 30% declining balance Leasehold improvements ​ Straight-line over shorter of estimated useful life or lease term
Goodwill	Goodwill Goodwill is the excess of the purchase price over the fair value of identifiable net assets acquired in business combinations accounted for under the acquisition method of accounting. The Company does not amortize goodwill. The Company tests its goodwill annually during the fourth quarter of its fiscal year or when events and circumstances indicate that those assets might not be recoverable. Impairment testing of goodwill is required at the reporting unit level (operating segment or one level below operating segment). Prior to performing the impairment test, the Company may make a qualitative assessment of the likelihood of goodwill impairment in order to determine whether a detailed quantitative analysis is required. The impairment test involves comparing the estimated fair values of the Company’s reporting units with the reporting units’ carrying amounts, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, a goodwill impairment loss is measured as the amount by which a reporting unit’s carrying amount exceeds its fair value, not to exceed the carrying amount of goodwill. ​
Intangible Assets	Intangible Assets Intangible assets consist of customer relationships, trade names and other assets acquired in conjunction with the purchases of businesses or purchases of assets from other companies. When management determines material intangible assets are acquired in conjunction with the purchase of a business, the Company determines the fair values of the identifiable intangible assets by considering management’s own analysis and an independent third-party valuation specialist’s appraisal. Intangible assets determined to have definite lives are amortized over their estimated useful lives.
Long-Lived Assets	Long-Lived Assets ​ The Company evaluates the recoverability of long-lived assets, including property and equipment, operating lease right-of-use assets and definite-lived intangible assets, for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Conditions that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used or a significant adverse change that would indicate the carrying amount of an asset or group of assets is not recoverable. For long-lived assets to be held and used, the Company recognizes an impairment loss if its carrying amount is not recoverable through its undiscounted cash flows and measures the impairment loss, if any, based on the difference between the carrying amount and fair value. Long-lived assets held for sale are reported at the lower of cost or fair value less costs to sell
Insurance Liabilities	Insurance Liabilities The Company is self-insured for certain losses related to medical claims. The Company has stop-loss coverage to limit the exposure arising from medical claims. In addition, the Company has deductible-based insurance policies for certain losses related to general liability, workers’ compensation and automobile. The deductible amount per incident is $0.3 million, $0.5 million and $1.0 million for general liability, workers’ compensation and automobile, respectively. The coverage consists of a deductible layer, a primary layer, a self-insured buffer layer, a lead umbrella layer and excess layers. The primary layer of coverage is from $0.3 million, $0.5 million and $1.0 million for deductibles for general liability, workers’ compensation, and automobile liability, respectively, to $5.0 million. The Company self-insures a buffer layer from $5.0 million to $10.0 million. The umbrella and excess layers cover claims from $10.0 million to $100.0 million. The expected ultimate cost for claims incurred as of the balance sheet date is not discounted and is recognized as a liability. Insurance losses for claims filed and claims incurred but not reported are accrued based upon estimates of the aggregate liability for uninsured claims using loss development factors and actuarial assumptions followed in the insurance industry and historical loss development experience. As of April 30, 2020 and 2019, the aggregate liabilities for medical self-insurance were $3.8 million and $3.4 million, respectively, and are included in other accrued expenses and current liabilities in the Consolidated Balance Sheets. As of April 30, 2020 and 2019, reserves for general liability, workers’ compensation and automobile totaled $19.4 million and $17.7 million, respectively, and are included in other accrued expenses and current liabilities and other liabilities in the Consolidated Balance Sheets. As of April 30, 2020 and 2019, expected recoveries for medical self-insurance, general liability, workers’ compensation and automobile totaled $6.0 million and $6.0 million, respectively, and are included in prepaid expenses and other current assets and other assets in the Consolidated Balance Sheets.
Restructuring	Restructuring The Company recognizes a liability for costs associated with an exit or disposal activity when the liability is incurred. After the appropriate level of management approves the detailed restructuring plan and the appropriate criteria for recognition are met, the Company establishes accruals for employee termination and other costs, as applicable. During the first quarter of 2019, the Company initiated a reduction in workforce as part of a strategic cost reduction plan to improve operational efficiency. The Company recorded $5.0 million of restructuring costs during the year ended April 30, 2019 in connection with the reduction in workforce and certain other restructuring activities, consisting primarily of severance and other employee costs. As of April 30, 2019, all costs related to the reduction in workforce had been paid. During the fourth quarter of 2020, the Company initiated a restructuring plan to close one of its facilities. The Company recorded $2.2 million of restructuring costs, consisting of $1.9 million for impairment of the operating lease right-of-use asset and $0.3 million for severance and other employee costs. Restructuring costs are classified within selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss).
Debt Issuance Costs	Debt Issuance Costs The Company defers debt issuance costs and amortizes them over the term of the related debt. The Company uses the straight-line method to amortize debt issuance costs for its revolving credit facility and uses the effective interest method to amortize debt issuance costs for its term loan facilities. Amortization of debt issuance costs is recorded in interest expense in the Consolidated Statements of Operations and Comprehensive Income (Loss). The Company classifies debt issuance costs for its revolving credit facilities as an asset in the Consolidated Balance Sheets and classifies debt issuance costs for its term loan facilities as a reduction of the related debt in the Consolidated Balance Sheets.
Stock Appreciation Rights, Deferred Compensation and Liabilities to Noncontrolling Interest Holders	Stock Appreciation Rights, Deferred Compensation and Liabilities to Noncontrolling Interest Holders Certain subsidiaries have equity-based compensation agreements with the subsidiary’s employees and minority stockholders. These agreements are stock appreciation rights, deferred compensation agreements and liabilities to noncontrolling interest holders. Since these agreements are typically settled in cash or notes, they are accounted for as liability awards and measured at fair value. See Note 13, “Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests,” for additional information with respect to these agreements.
Derivative Instruments	Derivative Instruments The Company has entered into derivative instruments to manage its exposure to certain financial risks. The Company’s derivative financial instruments are recognized as either assets or liabilities in the Consolidated Balance Sheets and measured at fair value. Derivative instruments that do not qualify as a hedge or are not designated as a hedge are adjusted to estimated fair value in earnings. Derivative instruments that meet hedge criteria are formally designated as hedges. For derivative instruments designated as a cash flow hedge, the Company recognizes the change in fair value, net of taxes, to accumulated other comprehensive income (loss) in the Consolidated Balance Sheets, and an amount is reclassified out of accumulated other comprehensive income (loss) into earnings to offset the earnings impact that is attributable to the risk being hedged. For derivative instruments designated as a fair value hedge, the Company recognizes the loss or gain attributable to the risk being hedged in earnings in the period of change with a corresponding offset recorded to the item for which the risk is being hedged. The Company performs the effectiveness testing of its designated hedges on a quarterly basis and the changes in ineffective portions of the derivatives, if any, are recognized immediately in earnings. See Note 14, “Derivative Instruments,” for additional information with respect to the Company’s derivative instruments.
Revenue Recognition	Revenue Recognition ​ The Company recognizes revenue upon transfer of control of promised goods to customers at an amount that reflects the consideration the Company expects to receive in exchange for those goods. Revenue is recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities. The Company includes shipping and handling costs billed to customers in net sales. These costs are recognized as a component of selling, general and administrative expenses when the Company does not bill the customer. See Note 2, “Revenue,” for information on the Company’s revenue recognition.
Cost of Sales	Cost of Sales Cost of sales reflects the direct cost of goods purchased from third parties, rebates earned from vendors, adjustments for inventory reserves and the cost of inbound freight.
Vendor Rebates	Vendor Rebates Typical arrangements with vendors provide for the Company to receive a rebate of a specified amount after it achieves any of a number of measures generally related to the volume of our purchases over a period of time. The Company records these rebates to effectively reduce its cost of sales in the period in which the Company sells the product. Throughout the year, the Company estimates the amount of rebates receivable for the periodic programs based upon the expected level of purchases. The Company accrues for the receipt of vendor rebates based on purchases and also reduces inventory to reflect the deferral of cost of sales.
Selling, General, and Administrative Expenses	Selling, General and Administrative Expenses ​
Advertising Expense	Advertising Expense The cost of advertising is expensed as incurred and included in selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss). Advertising expense was $3.3 million, $1.9 million and $1.8 million during the years ended April 30, 2020, 2019 and 2018, respectively.
Equity Based Compensation	Equity-Based Compensation As of April 30, 2020, the Company had various stock-based compensation plans, which are more fully described in Note 12, “Equity-Based Compensation.” The Company estimates the fair value of stock options using the Black-Scholes valuation model and determines the fair value of restricted stock units based on the quoted price of GMS’s common stock on the date of grant.
Income Taxes	Income Taxes Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized based on the difference between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Inherent in the measurement of deferred balances are certain judgments and interpretations of existing tax law and published guidance as applicable to our operations. The Company evaluates its deferred tax assets to determine if valuation allowances are required. In assessing the realizability of deferred tax assets, we consider both positive and negative evidence in determining whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The primary negative evidence considered includes the cumulative operating losses generated in prior periods. The primary positive evidence considered includes the reversal of deferred tax liabilities related to depreciation and amortization that would occur within the same jurisdiction and during the carry-forward period necessary to absorb the federal and state net operating losses and other deferred tax assets. The reversal of such liabilities would utilize the federal and state net operating losses and other deferred tax assets. The Company records amounts for uncertain tax positions that management believes are supportable, but are potentially subject to successful challenge by the applicable taxing authority. Consequently, changes in our assumptions and judgments could materially affect amounts recognized related to income tax uncertainties and may affect our results of operations or financial position. We believe our assumptions for estimates are reasonable, although actual results may have a positive or negative material impact on the balances of such tax positions. Historically, the variation of estimates to actual results is not significant and material variation is not expected in the future.
Concentrations of Risk	Concentrations of Risk COVID-19 Pandemic ​ Credit Risk. geographically diverse customers Additionally, the Company maintains allowances for potential credit losses. As of April 30, 2020 and 2019, no customer accounted for more than 10% of gross accounts receivable. ​ Supply Risk.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Authoritative guidance for fair value measurements establishes a three-level hierarchy that prioritizes the inputs to valuation models based upon the degree to which they are observable. The three levels of the fair value measurement hierarchy are as follows: Level 1 Inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. Level 2 Inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. Level 3 Inputs are unobservable inputs for which little or no market data exists, therefore requiring an entity to develop its own assumptions. ​ The carrying values of the Company’s cash, cash equivalents, trade receivables and trade payables approximate their fair values because of their short-term nature. Based on borrowing rates available to the Company for loans with similar terms, the carrying values of the Company’s debt instruments approximate fair value. See Note 15, “Fair Value Measurements,” for additional information with respect to the Company’s fair value measurements.
Earnings Per Share	​ Earnings Per Share Basic earnings per share is computed by dividing net income available to common stockholders by the weighted average number of outstanding shares of common stock for the period. Diluted earnings per share reflects the potential dilution that could occur if securities or other contracts to issue common stock, including stock options and restricted stock units (collectively “Common Stock Equivalents”), were exercised or converted into common stock The dilutive effect of outstanding stock options and stock units is reflected in diluted earnings per share by application of the treasury stock method. In applying the treasury stock method for stock-based compensation arrangements, the assumed proceeds are computed as the sum of the amount the employee must pay upon exercise and the amount of compensation cost attributed to future services and not yet recognized. Common Stock Equivalents The holders of the Company’s Exchangeable Shares (as defined in Note 3, “Business Acquisitions” and further described in Note 11, “Stockholders’ Equity”) were entitled to receive dividends or distributions that were equal to any dividends or distributions on the Company’s common stock. As a result, when the Exchangeable Shares were outstanding, they were classified as a participating security and thereby required the allocation of income that would have otherwise been available to common stockholders when calculating earnings per share. Diluted earnings per share was calculated by utilizing the most dilutive result of the if-converted and two-class methods. In both methods, net income attributable to common stockholders and the weighted-average common shares outstanding are adjusted to account for the impact of the assumed issuance of potential common shares that are dilutive, subject to dilution sequencing rules.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Leases – In February 2016, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance on accounting for leases. The new standard establishes a right-of-use (“ROU”) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than twelve months. Leases are classified as either finance or operating, with such classification affecting the pattern of expense recognition in the statement of operations. The new standard was effective for the Company’s fiscal year beginning May 1, 2019 (the first day of fiscal 2020), including interim reporting periods within that fiscal year. A modified transition approach was required for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. ​ On July 30, 2018, the FASB issued new guidance that provided entities with an additional (and optional) transition method to adopt the new lease standard. Under this new transition method, an entity initially applies the new lease standard at the adoption date and recognizes a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. ​ The Company adopted the new lease standard on May 1, 2019 using the optional transition method. The Company elected the package of practical expedients permitted in the guidance, which among other things, allows the Company to carry forward the historical accounting relating to lease identification and classification for existing leases upon adoption. The Company also elected to use the practical expedient to not separate lease and nonlease components. The Company did not elect the hindsight practical expedient. The Company made an accounting policy election to not recognize an ROU asset and lease liability for leases with an initial term of 12 months or less. ​ The adoption of the standard resulted in the recording of operating lease ROU assets and operating lease liabilities of $118.8 million on the Consolidated Balance Sheet as of the adoption date. The Company also reclassified deferred rent of $4.8 million from liabilities into its operating lease ROU assets. The adoption did not have a material impact on the Company’s Statement of Operations or Statement of Cash Flows. See Note 8, “Leases,” for information and disclosures regarding leases. ​ Goodwill – In January 2017, the FASB issued authoritative guidance that simplifies the accounting for goodwill impairments by eliminating Step 2 from the goodwill impairment test. Under the new guidance, goodwill impairment will be the amount by which a reporting unit’s carrying value exceeds its fair value. The new standard is effective for annual and any interim impairment tests for periods beginning after December 15, 2019. Early adoption is permitted. The Company adopted the new guidance on February 1, 2020 (the first day of its fiscal fourth quarter). ​ Recently Issued Accounting Pronouncements ​ Credit Losses – In June 2016, the FASB issued new guidance on credit losses on financial instruments. This guidance introduces a revised approach to the recognition and measurement of credit losses of certain financial instruments, including trade receivables, emphasizing an updated model based on expected losses rather than incurred losses. This new guidance is effective for annual reporting periods, and interim reporting periods contained therein, beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact of this guidance on its financial statements and related disclosures. ​ Fair Value Measurement Disclosures – In August 2018, the FASB issued new guidance that changes certain fair value measurement disclosure requirements. This guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. An entity is permitted to early adopt all of the disclosure changes or early adopt only the removed disclosure requirements and delay adoption of the additional disclosures until the effective date of this amendment. Except for changes to certain disclosures related to fair value measurements, the Company does not expect the adoption of this guidance to have a material impact on its financial statements. ​ Reference Rate Reform – In March 2020, the FASB issued new guidance to temporarily ease the potential burden in accounting for reference rate reform. The guidance provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rates that are expected to be discontinued, such as the London Interbank Offered Rate ("LIBOR"). The guidance was effective upon issuance and generally can be applied through December 31, 2022. The Company expects to elect optional expedients and exceptions provided by the guidance, as needed, related to its debt instruments, which include interest rates based on a LIBOR rate. The Company will evaluate and disclose the impact of this guidance in the period of election, as well as the nature and reason for doing so.

Business, Basis of Presentati_3

Business, Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Apr. 30, 2020
Business, Basis of Presentation and Summary of Significant Accounting Policies
Schedule of estimated useful lives of property and equipment	​ ​ ​ ​ Buildings 25 - 39 years Furniture, fixtures and automobiles 3 - 5 years Warehouse and delivery equipment 4 - 10 years Leasehold improvements Shorter of estimated useful life or lease term
Summary of depreciation expense for property and equipment of Canadian subsidiaries	​ ​ ​ ​ Vehicles and trucks 30% - 40% declining balance Furniture and fixtures 8% - 20% declining balance Buildings 4% declining balance Machinery and equipment 30% declining balance Leasehold improvements ​ Straight-line over shorter of estimated useful life or lease term

Business Acquisitions (Tables)

Business Acquisitions (Tables)	12 Months Ended
	Apr. 30, 2020
2020 Acquisitions
Acquisitions
Schedule of acquisitions completed	​ ​ ​ ​ ​ ​ Company Name Form of Acquisition Date of Acquisition J.P. Hart Lumber Company ​ Purchase of net assets ​ June 3, 2019 Rigney Building Supplies Ltd. ​ Purchase of 100% of outstanding common stock ​ November 1, 2019 Trowel Trades Supply, Inc. ​ Purchase of net assets ​ February 1, 2020
Schedule of preliminary allocation of the consideration transferred	​ ​ ​ ​ ​ ​ ​ Preliminary ​ ​ Acquisition ​ ​ Accounting ​ ​ (in thousands) Cash ​ $ 713 Trade accounts and notes receivable ​ 5,149 Inventories ​ 7,194 Other current assets ​ 72 Property and equipment ​ 6,788 Customer relationships ​ ​ 4,252 Tradenames ​ 644 Goodwill ​ 5,291 Liabilities assumed ​ (5,028) Fair value of consideration transferred ​ $ 25,075
2018 Acquisitions
Acquisitions
Schedule of acquisitions completed	​ ​ ​ ​ ​ ​ Company Name Form of Acquisition Date of Acquisition ASI Building Products, LLC ​ Purchase of net assets ​ August 1, 2017 Washington Builders Supply, Inc. ​ Purchase of net assets ​ October 2, 2017 Southwest Building Materials, Ltd. ​ Purchase of net assets ​ December 4, 2017 California-based distribution business of Grabber Construction Products, Inc. ​ Purchase of net assets ​ April 2, 2018 CMH Distributing, Inc. ​ Purchase of net assets ​ April 2, 2018
Schedule of preliminary allocation of the consideration transferred	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Preliminary ​ ​ ​ ​ Final ​ ​ Acquisition ​ Adjustments/ ​ Acquisition ​ ​ Accounting ​ Reclassifications ​ Accounting ​ ​ (in thousands) Trade accounts and notes receivable ​ $ 4,872 ​ $ — ​ $ 4,872 Inventories ​ ​ 4,321 ​ ​ — ​ ​ 4,321 Property and equipment ​ 1,081 ​ — ​ 1,081 Tradenames ​ 1,000 ​ — ​ 1,000 Vendor agreement ​ 1,000 ​ — ​ 1,000 Other intangible assets ​ 620 ​ — ​ 620 Customer relationships ​ 9,358 ​ — ​ 9,358 Goodwill ​ 4,145 ​ 8 ​ 4,153 Liabilities assumed ​ (1,951) ​ — ​ (1,951) Fair value of consideration transferred ​ $ 24,446 ​ $ 8 ​ $ 24,454
Titan
Acquisitions
Schedule of preliminary allocation of the consideration transferred	The following table summarizes the acquisition accounting: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Preliminary ​ ​ ​ ​ Final ​ ​ Acquisition ​ Adjustments/ ​ Acquisition ​ ​ Accounting ​ Reclassifications ​ Accounting ​ ​ (in thousands) Cash $ 5,573 ​ $ — ​ $ 5,573 Trade accounts and notes receivable ​ 84,039 ​ 970 ​ 85,009 Inventories ​ ​ 60,272 ​ ​ — ​ ​ 60,272 Prepaid and other current assets ​ 8,334 ​ — ​ 8,334 Property and equipment ​ 37,263 ​ — ​ 37,263 Goodwill ​ ​ 196,524 ​ ​ (2,726) ​ ​ 193,798 Intangible assets ​ ​ 289,423 ​ ​ (2,469) ​ ​ 286,954 Accounts payable and accrued expenses ​ ​ (40,833) ​ ​ (970) ​ ​ (41,803) Contingent consideration ​ ​ (12,039) ​ ​ — ​ ​ (12,039) Deferred income taxes ​ (14,337) ​ 2,085 ​ (12,252) Fair value of consideration transferred ​ $ 614,219 ​ $ (3,110) ​ $ 611,109

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Apr. 30, 2020
Property and Equipment
Schedule of components of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 ​ ​ (in thousands) Land ​ $ 52,581 ​ $ 52,031 Buildings and leasehold improvements ​ 110,322 ​ 99,300 Machinery and equipment ​ 300,133 ​ 252,504 Construction in progress ​ 985 ​ 2,097 Total property and equipment ​ 464,021 ​ 405,932 Less: accumulated depreciation and amortization ​ 158,554 ​ 123,583 Total property and equipment, net of accumulated depreciation ​ $ 305,467 ​ $ 282,349

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Apr. 30, 2020
Goodwill and Intangible Assets
Schedule of changes in the carrying amount of goodwill	​ ​ ​ ​ ​ ​ Carrying ​ ​ Amount ​ ​ (in thousands) Balance as of April 30, 2018 ​ $ 427,645 Goodwill recognized from acquisitions ​ ​ 196,267 Purchase price adjustments from prior periods ​ ​ 8 Translation adjustment ​ (6,593) Balance as of April 30, 2019 ​ ​ 617,327 Impairment of goodwill ​ ​ (63,074) Goodwill recognized from acquisitions ​ ​ 5,291 Translation adjustment ​ (6,471) Balance as of April 30, 2020 ​ $ 553,073
Schedule of components of definite-lived intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ Weighted ​ April 30, 2020 ​ ​ Useful ​ Average ​ Gross ​ ​ ​ Net ​ ​ Lives ​ Amortization ​ Carrying ​ Accumulated ​ Carrying ​ (years) Period Amount Amortization Value ​ ​ (dollars in thousands) Customer relationships ​ 5 - 16 ​ 12.8 ​ $ 516,928 ​ $ 270,029 ​ $ 246,899 Definite-lived tradenames ​ 5 - 20 ​ 16.3 ​ 55,654 ​ 10,474 ​ 45,180 Vendor agreements ​ 8 - 10 ​ 8.3 ​ 6,644 ​ 4,567 ​ 2,077 Developed technology ​ 5 ​ 4.9 ​ ​ 5,036 ​ ​ 1,963 ​ ​ 3,073 Leasehold interests ​ 1 - 15 ​ 7.6 ​ 3,679 ​ 2,101 ​ 1,578 Other ​ 3 - 5 ​ 3.4 ​ ​ 4,157 ​ ​ 2,447 ​ ​ 1,710 Totals ​ ​ ​ ​ ​ $ 592,098 ​ $ 291,581 ​ $ 300,517 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ Weighted ​ April 30, 2019 ​ ​ Useful ​ Average ​ Gross ​ ​ ​ Net ​ ​ Lives Amortization Carrying Accumulated Carrying ​ (years) Period Amount Amortization Value ​ ​ (dollars in thousands) Customer relationships ​ 5 - 16 ​ 12.8 ​ $ 520,703 ​ $ 214,044 ​ $ 306,659 Definite-lived tradenames ​ 5 - 20 ​ 16.3 ​ 56,018 ​ 6,993 ​ 49,025 Vendor agreements ​ 8 - 10 ​ 8.3 ​ 6,644 ​ 3,761 ​ 2,883 Developed technology ​ 5 ​ 4.9 ​ ​ 5,209 ​ ​ 971 ​ ​ 4,238 Leasehold interests ​ 1 - 15 ​ 7.6 ​ 3,707 ​ 1,502 ​ 2,205 Other ​ 3 - 5 ​ 3.4 ​ ​ 4,118 ​ ​ 1,182 ​ ​ 2,936 Totals ​ ​ ​ ​ ​ $ 596,399 ​ $ 228,453 ​ $ 367,946

Other Accrued Expenses and Cu_2

Other Accrued Expenses and Current Liabilities (Tables)	12 Months Ended
	Apr. 30, 2020
Other Accrued Expenses and Current Liabilities
Schedule of components of other accrued expenses and current liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 ​ ​ (in thousands) Insurance related liabilities ​ $ 12,922 ​ $ 14,110 Customer rebates payable ​ 10,211 ​ 7,944 Sales taxes payable ​ 9,493 ​ 10,448 Reserve for sales returns ​ ​ 4,081 ​ ​ 4,701 Income taxes payable ​ ​ 2,844 ​ ​ 14,063 Real estate and personal property taxes ​ 2,182 ​ 2,010 Contingent consideration ​ 2,018 ​ 13,073 Other ​ 20,061 ​ 13,499 Total other accrued expenses and current liabilities ​ $ 63,812 ​ $ 79,848

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Apr. 30, 2020
Long-Term Debt
Schedule of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 ​ ​ (in thousands) Term Loan Facility (1) (2) ​ $ 866,301 ​ $ 972,650 ABL Facility ​ 80,000 ​ 43,972 Finance lease obligations ​ 128,767 ​ 109,286 Installment notes at fixed rates up to 5.0%, due in monthly and annual installments through 2024 (3) ​ 15,218 ​ 15,287 Canadian Facility ​ 7,194 ​ ​ — Carrying value of debt ​ 1,097,480 ​ 1,141,195 Less current portion ​ 50,201 ​ 42,118 Long-term debt ​ $ 1,047,279 ​ $ 1,099,077 (1) Net of unamortized discount of $1,602 and $2,149 as of April 30, 2020 and 2019, respectively. (2) Net of deferred financing costs of $9,000 and $12,072 as of April 30, 2020 and 2019, respectively. (3) Net of unamortized discount of $1,098 and $1,200 as of April 30, 2020 and 2019, respectively. ​
Scheduled of maturities of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan ​ ​ ABL ​ Finance ​ Installment ​ Canadian ​ ​ ​ ​ Facility(1) ​ Facility Leases Notes(2) ​ Facility ​ Total Year ending April 30, ​ (in thousands) 2021 ​ $ 9,968 ​ $ — ​ $ 35,530 ​ $ 4,874 ​ $ — ​ $ 50,372 2022 ​ 9,968 ​ ​ — ​ ​ 32,547 ​ ​ 4,438 ​ ​ — ​ 46,953 2023 ​ 9,968 ​ ​ — ​ ​ 27,062 ​ ​ 4,404 ​ ​ 7,194 ​ 48,628 2024 ​ 9,968 ​ ​ — ​ ​ 19,974 ​ ​ 1,781 ​ ​ — ​ 31,723 2025 ​ 9,968 ​ ​ 80,000 ​ ​ 9,983 ​ ​ 819 ​ ​ — ​ 100,770 Thereafter ​ 827,063 ​ ​ — ​ ​ 3,671 ​ ​ — ​ ​ — ​ 830,734 ​ ​ $ 876,903 ​ $ 80,000 ​ $ 128,767 ​ $ 16,316 ​ $ 7,194 ​ $ 1,109,180 ​ (1) (2)

Leases (Tables)

Leases (Tables)	12 Months Ended
	Apr. 30, 2020
Leases
Summary of components of lease expense	​ ​ ​ ​ ​ ​ ​ Year ​ ​ Ended ​ ​ April 30, 2020 ​ ​ (in thousands) Finance lease cost: ​ ​ ​ Amortization of right-of-use assets ​ $ 24,352 Interest on lease liabilities ​ ​ 13,316 Operating lease cost ​ ​ 42,846 Variable lease cost ​ ​ 12,555 Total lease cost ​ $ 93,069
Summary of components of supplemental cash flow information related to leases	​ ​ ​ ​ ​ ​ ​ Year ​ ​ Ended ​ ​ April 30, 2020 ​ ​ (in thousands) Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ Operating cash flows from operating leases ​ $ 42,150 Operating cash flows from finance leases ​ ​ 13,316 Financing cash flows from finance leases ​ ​ 25,275 Right-of-use assets obtained in exchange for lease obligations ​ ​ ​ Operating leases ​ ​ 38,143 Finance leases ​ ​ 50,484
Summary of other lease information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ ​ 2020 2019 ​ ​ (in thousands) Finance leases included in property and equipment ​ ​ ​ ​ ​ ​ Property and equipment ​ $ 171,380 ​ $ 134,931 Accumulated depreciation ​ ​ (41,737) ​ ​ (27,686) Property and equipment, net ​ $ 129,643 ​ $ 107,245 Weighted-average remaining lease term (years) ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 4.9 ​ ​ ​ Finance leases ​ ​ 3.6 ​ ​ ​ Weighted-average discount rate ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 5.5 % ​ ​ Finance leases ​ ​ 5.0 % ​ ​
Schedule of maturities for finance leases	Future minimum lease payments under non-cancellable leases as of April 30, 2020 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance Operating Year Ending April 30, ​ (in thousands) 2021 ​ $ 46,116 ​ $ 38,960 2022 ​ 39,328 ​ 30,387 2023 ​ 30,525 ​ 23,655 2024 ​ 21,234 ​ 18,775 2025 ​ 10,544 ​ 12,154 Thereafter ​ 3,647 ​ 16,848 Total lease payments ​ ​ 151,394 ​ ​ 140,779 Less imputed interest ​ 22,627 ​ 18,134 Total ​ $ 128,767 ​ $ 122,645
Schedule of maturities for operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ Finance Operating Year Ending April 30, ​ (in thousands) 2021 ​ $ 46,116 ​ $ 38,960 2022 ​ 39,328 ​ 30,387 2023 ​ 30,525 ​ 23,655 2024 ​ 21,234 ​ 18,775 2025 ​ 10,544 ​ 12,154 Thereafter ​ 3,647 ​ 16,848 Total lease payments ​ ​ 151,394 ​ ​ 140,779 Less imputed interest ​ 22,627 ​ 18,134 Total ​ $ 128,767 ​ $ 122,645

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Apr. 30, 2020
Income Taxes
Schedule of components of income before taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 2018 ​ ​ (in thousands) United States ​ $ 106,850 ​ $ 62,878 ​ $ 83,854 Foreign ​ ​ (60,525) ​ ​ 7,163 ​ ​ — Income before taxes ​ $ 46,325 ​ $ 70,041 ​ $ 83,854
Schedule of components of income tax expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 2018 ​ ​ (in thousands) Current ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 12,537 ​ $ 11,858 ​ $ 30,827 Foreign ​ ​ 1,624 ​ ​ 13,739 ​ ​ — State ​ 7,857 ​ 5,929 ​ 6,409 Total current ​ 22,018 ​ 31,526 ​ 37,236 Deferred ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ 8,986 ​ 453 ​ (14,796) Foreign ​ ​ (7,347) ​ ​ (16,931) ​ ​ — State ​ (713) ​ (1,009) ​ (1,557) Total deferred ​ 926 ​ (17,487) ​ (16,353) Total provision for income taxes ​ $ 22,944 ​ $ 14,039 ​ $ 20,883
Summary of significant differences between federal statutory tax rate and effective tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 2018 ​ ​ (in thousands) Federal income taxes at statutory rate ​ $ 9,747 ​ $ 14,715 ​ $ 25,492 State income taxes, net of federal income tax benefit ​ 4,054 ​ 2,440 ​ 1,900 Impact of foreign rate differences ​ ​ (2,861) ​ ​ 418 ​ ​ — Impact of rate difference on impairment of goodwill ​ ​ 7,630 ​ ​ — ​ ​ — Net change in valuation allowance ​ 9,070 ​ 664 ​ 151 Nondeductible meals & entertainment ​ 592 ​ 635 ​ 822 Equity-based compensation ​ ​ (1,196) ​ ​ (53) ​ ​ — GILTI ​ ​ 704 ​ ​ 241 ​ ​ — Nondeductible transaction costs ​ 90 ​ 529 ​ 2 Net deferred benefit due to Tax Cuts and Jobs Act ​ ​ — ​ ​ — ​ ​ (6,763) Intercompany interest expense ​ ​ (5,361) ​ ​ (5,255) ​ ​ — Other ​ 475 ​ (295) ​ (721) Total provision for income taxes ​ $ 22,944 ​ $ 14,039 ​ $ 20,883
Schedule of tax effects of temporary differences which give rise to deferred income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ 2020 2019 Deferred income tax assets: ​ (in thousands) Allowances on accounts and notes receivable ​ $ 2,016 ​ $ 2,306 Accrued payroll and related costs ​ 1,859 ​ 1,577 Insurance reserves ​ 2,501 ​ 1,746 Inventory costs ​ 2,630 ​ 2,066 Deferred compensation ​ ​ 7,426 ​ ​ 6,854 Equity compensation ​ 2,695 ​ 2,944 Derivative instrument ​ 7,850 ​ 1,358 Acquisition related costs ​ 1,311 ​ 1,779 Net operating loss carry-forwards ​ 1,595 ​ 1,745 Disallowed interest expense ​ ​ 736 ​ ​ 2,507 Investment in partnerships ​ ​ 16,535 ​ ​ 4,676 Deferred rent ​ 1,112 ​ 604 Noncompete agreements ​ 120 ​ 133 Other deferred tax assets, net ​ 1,424 ​ 1,394 Total deferred income tax assets ​ 49,810 ​ 31,689 Less: Valuation allowance ​ (10,183) ​ (1,112) Total deferred income tax assets, net of valuation allowance ​ 39,627 ​ 30,577 Deferred income tax liabilities: ​ ​ ​ ​ ​ ​ Amortization of intangible assets ​ (18,917) ​ (22,950) Rebates ​ ​ (400) ​ ​ (72) Depreciation ​ (21,508) ​ (10,495) Deferred financing costs ​ (1,582) ​ (2,075) Other deferred tax liabilities, net ​ (334) ​ ​ (535) Total deferred income tax liabilities ​ (42,741) ​ (36,127) Deferred income tax liabilities, net ​ $ (3,114) ​ $ (5,550)

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Apr. 30, 2020
Stockholders' Equity
Schedule of changes to accumulated other comprehensive loss, net of tax, by component	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ Foreign ​ Derivative ​ Other ​ ​ Currency ​ Financial ​ Comprehensive ​ ​ Translation ​ Instruments ​ Income (Loss) ​ ​ (in thousands) Balance as of April 30, 2017 ​ $ — ​ $ (884) ​ $ (884) Other comprehensive income before reclassification ​ ​ — ​ ​ 309 ​ 309 Reclassification to earnings from accumulated other comprehensive (loss) income ​ ​ — ​ ​ 1,016 ​ 1,016 Balance as of April 30, 2018 ​ ​ — ​ ​ 441 ​ ​ 441 Other comprehensive loss before reclassification ​ ​ (22,320) ​ ​ (5,423) ​ ​ (27,743) Reclassification to earnings from accumulated other comprehensive (loss) income ​ ​ — ​ ​ 728 ​ ​ 728 Balance as of April 30, 2019 ​ ​ (22,320) ​ ​ (4,254) ​ ​ (26,574) Other comprehensive loss before reclassification ​ ​ (18,257) ​ ​ (20,251) ​ ​ (38,508) Reclassification to earnings from accumulated other comprehensive (loss) income ​ ​ — ​ ​ — ​ ​ — Balance as of April 30, 2020 ​ $ (40,577) ​ $ (24,505) ​ $ (65,082)

Equity-Based Compensation - (Ta

Equity-Based Compensation - (Tables)	12 Months Ended
	Apr. 30, 2020
Equity-Based Compensation
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ ​ ​ ​ ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ Number of ​ Exercise ​ Contractual ​ Intrinsic ​ ​ Options ​ Price ​ Life (years) ​ Value ​ ​ (shares and dollars in thousands) Outstanding as of April 30, 2019 2,080 ​ $ 16.34 6.15 ​ $ 7,615 Options granted 386 ​ ​ 21.63 ​ Options exercised (874) ​ 13.22 ​ Options forfeited (105) ​ 25.73 ​ Options expired — ​ — ​ ​ Outstanding as of April 30, 2020 1,487 ​ $ 18.85 6.40 ​ $ 3,895 Exercisable as of April 30, 2020 941 ​ $ 16.32 4.98 ​ $ 3,866 Vested and expected to vest as of April 30, 2020 1,481 ​ $ 18.83 6.39 ​ $ 3,895
Schedule of weighted average assumptions used in Black-Scholes option-pricing model	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 ​ 2019 ​ 2018 Volatility ​ 49.86 % ​ 33.71 % 30.86 % Expected life (years) ​ 6.0 ​ ​ 6.0 ​ 6.0 ​ Risk-free interest rate ​ 1.97 % ​ 2.87 % 2.18 % Dividend yield ​ — % ​ — % — %
Summary of restricted stock unity activity	​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of ​ Average ​ ​ Restricted ​ Exercise ​ ​ Stock Units ​ Price ​ ​ (shares in thousands) Outstanding as of April 30, 2019 ​ 193 ​ $ 25.48 Granted ​ 233 ​ ​ 21.67 Vested ​ (100) ​ ​ 24.48 Forfeited ​ (40) ​ ​ 25.29 Outstanding as of April 30, 2020 ​ 286 ​ $ 22.71

Stock Appreciation Rights, De_2

Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests (Tables)	12 Months Ended
	Apr. 30, 2020
Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests
Summary of changes to the liabilities for stock appreciation rights, deferred compensation and redeemable noncontrolling interests	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock ​ ​ ​ ​ Redeemable ​ ​ Appreciation ​ Deferred ​ Noncontrolling ​ ​ Rights ​ Compensation ​ Interests ​ ​ (in thousands) Balance as of April 30, 2018 ​ $ 21,944 ​ $ 2,222 $ 16,170 Amounts redeemed ​ ​ (1,216) ​ ​ (715) ​ ​ (4,673) Change in fair value ​ 2,730 ​ 188 ​ 1,001 Balance as of April 30, 2019 ​ ​ 23,458 ​ ​ 1,695 ​ ​ 12,498 Amounts redeemed ​ (825) ​ (108) ​ (4,644) Change in fair value ​ 1,572 ​ 73 ​ 446 Balance as of April 30, 2020 ​ $ 24,205 ​ $ 1,660 ​ $ 8,300 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of April 30, 2019 ​ $ 1,355 ​ $ 108 ​ $ 1,569 Classified as long-term as of April 30, 2019 ​ ​ 22,103 ​ ​ 1,587 ​ ​ 10,929 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of April 30, 2020 ​ $ 624 ​ $ — ​ $ — Classified as long-term as of April 30, 2020 ​ ​ 23,581 ​ ​ 1,660 ​ ​ 8,300

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Apr. 30, 2020
Fair Value Measurements
Schedule of liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ ​ 2020 ​ 2019 ​ ​ (in thousands) Interest rate swaps (Level 2) ​ $ 32,218 ​ $ 5,613 Stock appreciation rights (Level 3) ​ ​ 24,205 ​ ​ 23,458 Deferred compensation (Level 3) ​ ​ 1,660 ​ 1,695 Noncontrolling interest holders (Level 3) ​ ​ 8,300 ​ ​ 12,498 Contingent consideration (Level 3) ​ ​ — ​ 12,354

Segments (Tables)

Segments (Tables)	12 Months Ended
	Apr. 30, 2020
Segments
Schedule of segment results	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2020 ​ ​ ​ ​ April 30, 2020 ​ ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ Total ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ Assets ​ ​ (in thousands) Geographic divisions ​ $ 3,213,938 ​ $ 1,053,555 ​ $ 114,279 ​ $ 297,646 ​ $ 2,264,208 Other ​ 27,369 ​ 9,659 ​ 233 ​ 2,113 ​ 18,745 Corporate ​ — ​ — ​ 2,021 ​ — ​ 5,829 ​ ​ $ 3,241,307 ​ $ 1,063,214 ​ $ 116,533 ​ $ 299,759 ​ $ 2,288,782 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2019 ​ ​ ​ ​ April 30, 2019 ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ Total ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ Assets ​ ​ (in thousands) Geographic divisions ​ $ 3,090,314 ​ $ 994,981 ​ $ 114,558 ​ $ 293,190 ​ $ 2,125,518 Other ​ 25,718 ​ 9,138 ​ 220 ​ 2,479 ​ 16,897 Corporate ​ — ​ — ​ 2,681 ​ — ​ 7,139 ​ ​ $ 3,116,032 ​ $ 1,004,119 ​ $ 117,459 ​ $ 295,669 ​ $ 2,149,554 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2018 ​ ​ ​ ​ April 30, 2018 ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ Total ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ Assets ​ ​ (in thousands) Geographic divisions ​ $ 2,487,557 ​ $ 809,884 ​ $ 64,491 ​ $ 196,903 ​ $ 1,434,371 Other ​ 23,912 ​ 8,692 ​ 242 ​ 2,355 ​ 12,854 Corporate ​ — ​ — ​ 797 ​ — ​ 7,286 ​ ​ $ 2,511,469 ​ $ 818,576 ​ $ 65,530 ​ $ 199,258 ​ $ 1,454,511 ​
Reconciliation of Adjusted EBITDA to net income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 2019 2018 ​ ​ (in thousands) Net income ​ $ 23,381 ​ $ 56,002 ​ $ 62,971 Interest expense ​ 67,718 ​ ​ 73,677 ​ ​ 31,395 Write-off of debt discount and deferred financing fees ​ ​ 1,331 ​ ​ — ​ ​ 74 Interest income ​ (88) ​ ​ (66) ​ ​ (177) Provision for income taxes ​ 22,944 ​ ​ 14,039 ​ ​ 20,883 Depreciation expense ​ 51,332 ​ ​ 46,456 ​ ​ 24,075 Amortization expense ​ 65,201 ​ ​ 71,003 ​ ​ 41,455 Impairment of goodwill ​ ​ 63,074 ​ ​ — ​ ​ — Stock appreciation expense(a) ​ ​ 1,572 ​ ​ 2,730 ​ ​ 2,318 Redeemable noncontrolling interests(b) ​ 520 ​ ​ 1,188 ​ ​ 1,868 Equity-based compensation(c) ​ 7,060 ​ ​ 3,906 ​ ​ 1,695 Severance and other permitted costs(d) ​ 5,733 ​ ​ 8,152 ​ ​ 581 Transaction costs (acquisitions and other)(e) ​ 2,414 ​ ​ 7,858 ​ ​ 3,370 Loss (gain) on disposal and impairment of assets(f) ​ 658 ​ ​ (525) ​ ​ (509) Effects of fair value adjustments to inventory(g) ​ 575 ​ ​ 4,176 ​ ​ 324 Change in fair value of financial instruments(h) ​ — ​ ​ 6,395 ​ ​ 6,125 Gain on legal settlement ​ ​ (14,029) ​ ​ — ​ ​ — Secondary public offering costs(i) ​ ​ 363 ​ ​ — ​ ​ 1,525 Debt transaction costs(j) ​ ​ — ​ ​ 678 ​ ​ 1,285 Adjusted EBITDA ​ $ 299,759 ​ $ 295,669 ​ $ 199,258 (a) Represents non-cash expense related to stock appreciation rights agreements. (b) Represents non-cash compensation expense related to changes in the fair values of noncontrolling interests . (c) Represents non-cash equity-based compensation expense related to the issuance of share-based awards. (d) Represents severance expenses and other costs permitted in calculations under the ABL Facility and the Term Loan Facility, including certain unusual, nonrecurring costs due to COVID-19. (e) Represents costs related to acquisitions paid to third parties. (f) The year ended April 30, 2020 includes a $1.9 million impairment of operating lease right-of-use assets resulting from a restructuring plan to close one of the Company’s facilities. (g) Represents the non-cash cost of sales impact of purchase accounting adjustments to increase inventory to its estimated fair value. (h) Represents the mark-to-market adjustments for derivative financial instruments. (i) Represents costs paid to third-party advisors related to secondary offerings of our common stock. (j) Represents costs paid to third-party advisors related to debt refinancing activities.
Schedule of net sales to external customers by main product lines	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 ​ 2019 ​ 2018 ​ ​ (in thousands) Wallboard ​ $ 1,329,775 $ 1,272,068 $ 1,109,552 Ceilings ​ 475,827 451,695 387,360 Steel framing ​ 502,122 506,805 411,630 Other products ​ 933,583 885,464 602,927 Total net sales ​ $ 3,241,307 $ 3,116,032 $ 2,511,469
Schedule of net sales by major geographic area	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ 2020 2019 ​ 2019 ​ ​ (in thousands) United States ​ $ 2,805,920 $ 2,701,678 $ 2,511,469 Canada ​ 435,387 414,354 — Total net sales ​ $ 3,241,307 $ 3,116,032 ​ $ 2,511,469
Schedule of property and equipment by major geographic area	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ April 30, ​ April 30, ​ 2020 2019 ​ ​ (in thousands) United States ​ $ 270,855 ​ $ 249,857 Canada ​ 34,612 32,492 Total property and equipment, net ​ $ 305,467 $ 282,349

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Apr. 30, 2020
Earnings Per Common Share
Schedule of computation of basic and diluted earnings per share of common stock	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, ​ ​ 2020 2019 2018 ​ ​ (in thousands, except per share data) Net income ​ $ 23,381 ​ $ 56,002 ​ $ 62,971 Less: Net income allocated to participating securities ​ ​ 74 ​ ​ 1,382 ​ ​ — Net income attributable to common stockholders ​ $ 23,307 $ 54,620 ​ $ 62,971 Basic earnings per common share: ​ ​ ​ ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 41,853 ​ 40,914 ​ 41,015 Basic earnings per common share ​ $ 0.56 ​ $ 1.33 ​ $ 1.54 Diluted earnings per common share: ​ ​ ​ Basic weighted average common shares outstanding ​ 41,853 ​ 40,914 ​ 41,015 Add: Common Stock Equivalents ​ 651 ​ 675 ​ 1,148 Diluted weighted average common shares outstanding ​ 42,504 ​ 41,589 ​ 42,163 Diluted earnings per common share ​ $ 0.55 ​ $ 1.31 ​ $ 1.49

Valuation and Qualifying Acco_2

Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Apr. 30, 2020
Allowances for Accounts Receivable
Valuation and Qualifying Accounts
Schedule of Valuation and Qualifying Accounts	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance ​ ​ Charged to ​ ​ Balance ​ ​ at Beginning ​ ​ ​ ​ Other ​ ​ ​ ​ at End of ​ ​ of Period ​ Provision ​ Accounts(a) ​ Deductions ​ Period ​ ​ (in thousands) Fiscal Year Ended April 30, 2020 ​ $ (6,432) ​ $ (2,348) ​ $ 938 ​ $ 2,701 ​ $ (5,141) Fiscal Year Ended April 30, 2019 ​ ​ (9,633) ​ ​ (1,064) ​ ​ 2,435 ​ ​ 1,830 ​ ​ (6,432) Fiscal Year Ended April 30, 2018 ​ (9,851) ​ (366) ​ (596) ​ 1,180 ​ (9,633) (a) Charged to other accounts represents the net (increase) decrease for specifically reserved accounts, as well as the net change in reserves for sales discounts, service charges and sales returns. The adoption of the new revenue recognition guidance on May 1, 2018 resulted in a $3.6 million reclassification in the Consolidated Balance Sheet from trade accounts and notes receivable to other accrued expenses and current liabilities for estimated sales returns. This reclass is reflected in charged to other accounts for the fiscal year ended April 30, 2019. ​
Valuation Allowance on Deferred Tax Assets
Valuation and Qualifying Accounts
Schedule of Valuation and Qualifying Accounts	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance Additions ​ Balance ​ ​ at Beginning ​ Charged to Costs ​ ​ ​ at End of ​ ​ of Period ​ and Expenses ​ Deductions ​ Period ​ ​ (in thousands) Fiscal Year Ended April 30, 2020 ​ $ (1,112) ​ $ (9,071) ​ $ — ​ $ (10,183) Fiscal Year Ended April 30, 2019 ​ ​ (448) ​ ​ (664) ​ ​ — ​ ​ (1,112) Fiscal Year Ended April 30, 2018 ​ (297) ​ (151) ​ — ​ (448)

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Apr. 30, 2020
Selected Quarterly Financial Data (Unaudited)
Schedule of selected quarterly financial information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2020 ​ First Second Third Fourth ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ ​ (in thousands, except per share data) Net sales ​ $ 847,176 ​ $ 861,929 ​ $ 761,352 ​ $ 770,850 Gross profit ​ 273,654 ​ 284,493 ​ 253,473 ​ 251,594 Net income (loss)(1) ​ 24,820 ​ 29,138 ​ 10,879 ​ (41,456) Per share data ​ ​ ​ ​ Weighted average shares outstanding(2): ​ ​ ​ ​ Basic ​ 41,001 ​ 41,761 ​ 42,223 ​ 42,435 Diluted ​ 41,615 ​ 42,635 ​ 42,949 ​ 42,435 Net income (loss) per share(2): ​ ​ ​ ​ Basic ​ $ 0.60 ​ $ 0.70 ​ $ 0.26 ​ $ (0.98) Diluted ​ $ 0.59 ​ $ 0.68 ​ $ 0.25 ​ $ (0.98) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended April 30, 2019 ​ First Second Third Fourth ​ ​ Quarter ​ Quarter ​ Quarter ​ Quarter ​ ​ (in thousands, except per share data) Net sales ​ $ 778,144 ​ $ 833,837 ​ $ 723,902 ​ $ 780,149 Gross profit ​ 244,816 ​ 268,150 ​ 234,226 ​ 256,927 Net income(3) ​ 8,650 ​ 24,912 ​ 5,815 ​ 16,625 Per share data ​ ​ ​ ​ Weighted average shares outstanding(2): ​ ​ ​ ​ Basic ​ 41,094 ​ 41,149 ​ 40,912 ​ 40,487 Diluted ​ 42,074 ​ 41,918 ​ 41,371 ​ 40,976 Net income per share(2): ​ ​ ​ ​ Basic ​ $ 0.21 ​ $ 0.59 ​ $ 0.14 ​ $ 0.40 Diluted ​ $ 0.20 ​ $ 0.58 ​ $ 0.14 ​ $ 0.39 (1) Net income for the fourth quarter of 2020 includes a $63.1 million non-cash impairment charge to goodwill and a $14.0 million gain on legal settlement. In February 2020, the Company received proceeds as part of a class action settlement. ​ (2) Basic and diluted net income per share are computed independently for each of the quarters presented. Therefore, the sum of the quarterly basic and diluted net income per share amounts may not equal annual basic and diluted net income per share amounts. ​ (3) Net income for the first quarter of 2019 includes a $5.7 million loss on change in fair value of financial instruments related to the Company’s foreign currency forward contract.

Business, Basis of Presentati_4

Business, Basis of Presentation and Summary of Significant Accounting Policies - Business (Details)	Apr. 30, 2020location
Minimum
Business
Number of branches through which products are distributed	260

Business, Basis of Presentati_5

Business, Basis of Presentation and Summary of Significant Accounting Policies - Property and Equipment (Details)	12 Months Ended
	Apr. 30, 2020
Buildings
Property and equipment
Depreciation expense for property and equipment (as a percent)	4.00%
Buildings | Minimum
Property and equipment
Estimated useful life	25 years
Buildings | Maximum
Property and equipment
Estimated useful life	39 years
Furniture, fixtures and automobiles | Minimum
Property and equipment
Estimated useful life	3 years
Furniture, fixtures and automobiles | Maximum
Property and equipment
Estimated useful life	5 years
Warehouse and delivery equipment | Minimum
Property and equipment
Estimated useful life	4 years
Warehouse and delivery equipment | Maximum
Property and equipment
Estimated useful life	10 years
Vehicles and trucks | Minimum
Property and equipment
Depreciation expense for property and equipment (as a percent)	30.00%
Vehicles and trucks | Maximum
Property and equipment
Depreciation expense for property and equipment (as a percent)	40.00%
Furniture and fixtures | Minimum
Property and equipment
Depreciation expense for property and equipment (as a percent)	8.00%
Furniture and fixtures | Maximum
Property and equipment
Depreciation expense for property and equipment (as a percent)	20.00%
Machinery and equipment
Property and equipment
Depreciation expense for property and equipment (as a percent)	30.00%

Business, Basis of Presentati_6

Business, Basis of Presentation and Summary of Significant Accounting Policies - Insurance Liabilities (Details) - USD ($) $ in Millions	Apr. 30, 2020	Apr. 30, 2019
Other accrued expenses and current liabilities.
Insurance Liabilities
Aggregate liabilities for medical self-insurance	$ 3.8	$ 3.4
General liability
Insurance Liabilities
Deductible amount	0.3
General liability | Minimum
Insurance Liabilities
Primary layer of insurance coverage	0.3
Workers' compensation
Insurance Liabilities
Deductible amount	0.5
Workers' compensation | Minimum
Insurance Liabilities
Primary layer of insurance coverage	0.5
Automobile
Insurance Liabilities
Deductible amount	1
Automobile | Minimum
Insurance Liabilities
Primary layer of insurance coverage	1
General liability, workers' compensation and automobile | Other accrued expenses and current liabilities.
Insurance Liabilities
Reserve for insurance	19.4	17.7
General liability, workers' compensation and automobile | Prepaid expenses and other current assets
Insurance Liabilities
Insurance recovery receivable	6	$ 6
General liability, workers' compensation and automobile | Minimum
Insurance Liabilities
Buffer layer of insurance coverage	5
Excess layer of insurance coverage	10
General liability, workers' compensation and automobile | Maximum
Insurance Liabilities
Primary layer of insurance coverage	5
Buffer layer of insurance coverage	10
Excess layer of insurance coverage	$ 100

Business, Basis of Presentati_7

Business, Basis of Presentation and Summary of Significant Accounting Policies - Restructuring charges (Details) $ in Millions	3 Months Ended	12 Months Ended
	Apr. 30, 2020USD ($)facility	Apr. 30, 2020USD ($)	Apr. 30, 2019USD ($)
Restructuring costs	$ 2.2
Number of facilities closed | facility	1
Impairment	$ 1.9	$ 1.9
Severance	$ 0.3
Selling, general and administrative expenses
Restructuring costs			$ 5

Business, Basis of Presentati_8

Business, Basis of Presentation and Summary of Significant Accounting Policies - Selling, General and Administrative Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Delivery expenses classification
Cost of sales (exclusive of depreciation and amortization shown separately below)	$ 2,178,093	$ 2,111,913	$ 1,692,893
Delivery | Selling, general and administrative expenses
Delivery expenses classification
Cost of sales (exclusive of depreciation and amortization shown separately below)	$ 243,000	$ 225,600	$ 228,000

Business, Basis of Presentati_9

Business, Basis of Presentation and Summary of Significant Accounting Policies - Advertising Expense and Credit and Economic Risk (Details) $ in Millions	12 Months Ended
	Apr. 30, 2020USD ($)customer	Apr. 30, 2019USD ($)customer	Apr. 30, 2018USD ($)
Selling, general and administrative expenses
Advertising Expense
Advertising Expense | $	$ 3.3	$ 1.9	$ 1.8
Accounts receivable
Advertising Expense
Number of major customers | customer	0	0

Business, Basis of Presentat_10

Business, Basis of Presentation and Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	May 01, 2019	Apr. 30, 2020
Adoption of new accounting pronouncement
Operating lease right-of-use assets		$ 115,257
Operating lease liability		122,645
Operating lease right-of-use assets obtained in exchange for lease obligations		$ 38,143
Adjustment | ASU 2016-02
Adoption of new accounting pronouncement
Operating lease right-of-use assets	$ 118,800
Operating lease liability	118,800
Operating lease right-of-use assets obtained in exchange for lease obligations	$ 4,800

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Revenue
Revenue, Practical Expedient, Financing Component [true false]	true
Revenue, Practical Expedient, Remaining Performance Obligation [true/false]	true
Receivables from contracts with customers	$ 393.6	$ 431.4

Business Acquisitions (Details)

Business Acquisitions (Details) $ in Thousands, shares in Millions, $ in Millions	Jun. 01, 2018USD ($)itemshares	Jun. 01, 2018CAD ($)shares	Jun. 07, 2017USD ($)	Apr. 30, 2020USD ($)segment	Apr. 30, 2019USD ($)	Apr. 30, 2018USD ($)	Nov. 01, 2019
Acquisitions
Loan repayment					$ 571,840	$ 477,616
Borrowings from the revolving credit facility				$ 880,698	981,148	513,878
Preliminary Purchase Price Allocation
Goodwill				$ 553,073	617,327	427,645
Number of reportable segments | segment				1
Goodwill and intangible assets
Goodwill expected to be deductible for U.S. federal income tax purposes				$ 2,100
Goodwill expected to be nondeductible for U.S. federal income tax purposes				3,200
Third Amendment
Acquisitions
Aggregate principal amount	$ 996,800
Third Amendment | LIBOR
Acquisitions
Margin added to variable rate (as a percent)	2.75%	2.75%
Variable rate floor (as a percent)	0.00%	0.00%
Term Loan Facility
Acquisitions
Loan repayment	$ 571,800		$ 477,600
Titan
Acquisitions
Number of locations | item	30
Number of provinces | item	5
Aggregate purchase price	$ 627,000	$ 800
Issuance of shares | shares	1.1	1.1
Purchase price
Fair value of consideration transferred	$ 611,100
Cash	581,500
Issuance preferred stock to current shareholders of Titan	29,600
Preliminary Purchase Price Allocation
Cash					5,573
Trade accounts and notes receivable					85,009
Inventories					60,272
Prepaid and other current assets					8,334
Property and equipment					37,263
Intangible assets					286,954
Goodwill					193,798
Accounts payable and accrued expenses					(41,803)
Contingent consideration					(12,039)
Deferred tax liability					(12,252)
Fair value of consideration transferred					611,109
Titan | Third Amendment
Acquisitions
Aggregate principal amount	$ 996,800
Titan | Third Amendment | LIBOR
Acquisitions
Margin added to variable rate (as a percent)	2.75%	2.75%
Variable rate floor (as a percent)	0.00%	0.00%
Titan | ABL facility
Acquisitions
Borrowings from the revolving credit facility	$ 143,000
Titan | Term Loan Facility
Acquisitions
Loan repayment	571,800
2018 Acquisitions
Purchase price
Fair value of consideration transferred						24,400
Preliminary Purchase Price Allocation
Trade accounts and notes receivable						4,872
Inventories						4,321
Property and equipment						1,081
Goodwill						4,153
Liabilities assumed						(1,951)
Fair value of consideration transferred						24,454
2018 Acquisitions | Tradenames
Preliminary Purchase Price Allocation
Intangible assets						1,000
2018 Acquisitions | Vendor agreement
Preliminary Purchase Price Allocation
Intangible assets						1,000
2018 Acquisitions | Other intangible assets
Preliminary Purchase Price Allocation
Intangible assets						620
2018 Acquisitions | Customer relationships
Preliminary Purchase Price Allocation
Goodwill						9,358
2020 Acquisitions
Purchase price
Fair value of consideration transferred				25,100
Preliminary Purchase Price Allocation
Cash				713
Trade accounts and notes receivable				5,149
Inventories				7,194
Other current assets				72
Property and equipment				6,788
Goodwill				5,291
Liabilities assumed				(5,028)
Fair value of consideration transferred				25,075
2020 Acquisitions | Customer relationships
Preliminary Purchase Price Allocation
Intangible assets				4,252
2020 Acquisitions | Tradenames
Preliminary Purchase Price Allocation
Intangible assets				$ 644
Rigney Building Supplies Ltd
Acquisitions
Outstanding common stock purchased (as a percent)							100.00%
As previously reported | Titan
Preliminary Purchase Price Allocation
Cash	5,573
Trade accounts and notes receivable	84,039
Inventories	60,272
Prepaid and other current assets	8,334
Property and equipment	37,263
Intangible assets	289,423
Goodwill	196,524
Accounts payable and accrued expenses	(40,833)
Contingent consideration	(12,039)
Deferred tax liability	(14,337)
Fair value of consideration transferred	$ 614,219
As previously reported | 2018 Acquisitions
Preliminary Purchase Price Allocation
Trade accounts and notes receivable						4,872
Inventories						4,321
Property and equipment						1,081
Goodwill						4,145
Liabilities assumed						(1,951)
Fair value of consideration transferred						24,446
As previously reported | 2018 Acquisitions | Tradenames
Preliminary Purchase Price Allocation
Intangible assets						1,000
As previously reported | 2018 Acquisitions | Vendor agreement
Preliminary Purchase Price Allocation
Intangible assets						1,000
As previously reported | 2018 Acquisitions | Other intangible assets
Preliminary Purchase Price Allocation
Intangible assets						620
As previously reported | 2018 Acquisitions | Customer relationships
Preliminary Purchase Price Allocation
Goodwill						9,358
Adjustment | Titan
Preliminary Purchase Price Allocation
Trade accounts and notes receivable					970
Intangible assets					(2,469)
Goodwill					(2,726)
Accounts payable and accrued expenses					(970)
Deferred tax liability					2,085
Fair value of consideration transferred					$ (3,110)
Adjustment | 2018 Acquisitions
Preliminary Purchase Price Allocation
Goodwill						8
Fair value of consideration transferred						$ 8

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Property and equipment
Total property and equipment	$ 464,021	$ 405,932
Accumulated depreciation	158,554	123,583
Property and equipment, net	305,467	282,349
Depreciation and amortization expense for property and equipment	51,300	46,500	$ 24,100
Land
Property and equipment
Total property and equipment	52,581	52,031
Buildings and leasehold improvements
Property and equipment
Total property and equipment	110,322	99,300
Machinery and equipment
Property and equipment
Total property and equipment	300,133	252,504
Construction in progress
Property and equipment
Total property and equipment	$ 985	$ 2,097

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020USD ($)	Apr. 30, 2020USD ($)segment	Apr. 30, 2019USD ($)
Carrying Amount of Goodwill
Balance		$ 617,327	$ 427,645
Impairment of goodwill	$ (63,100)	(63,074)
Goodwill acquired		5,291	196,267
Purchase price adjustments			8
Translation adjustment		(6,471)	(6,593)
Balance	553,073	$ 553,073	$ 617,327
Number of operating segments | segment		7
Canada
Carrying Amount of Goodwill
Impairment of goodwill	(63,100)
Balance	$ 120,900	$ 120,900

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Definite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Definite-lived intangible assets
Gross Carrying Amount	$ 592,098	$ 596,399
Accumulated Amortization	291,581	228,453
Net Carrying Value	$ 300,517	$ 367,946
Customer relationships
Definite-lived intangible assets
Weighted Average Amortization Period (in years)	12 years 9 months 18 days	12 years 9 months 18 days
Gross Carrying Amount	$ 516,928	$ 520,703
Accumulated Amortization	270,029	214,044
Net Carrying Value	$ 246,899	$ 306,659
Customer relationships | Minimum
Definite-lived intangible assets
Estimated Useful Lives (years)	5 years	5 years
Customer relationships | Maximum
Definite-lived intangible assets
Estimated Useful Lives (years)	16 years	16 years
Tradenames
Definite-lived intangible assets
Weighted Average Amortization Period (in years)	16 years 3 months 18 days	16 years 3 months 18 days
Gross Carrying Amount	$ 55,654	$ 56,018
Accumulated Amortization	10,474	6,993
Net Carrying Value	$ 45,180	$ 49,025
Tradenames | Minimum
Definite-lived intangible assets
Estimated Useful Lives (years)	5 years	5 years
Tradenames | Maximum
Definite-lived intangible assets
Estimated Useful Lives (years)	20 years	20 years
Vendor agreements
Definite-lived intangible assets
Weighted Average Amortization Period (in years)	8 years 3 months 18 days	8 years 3 months 18 days
Gross Carrying Amount	$ 6,644	$ 6,644
Accumulated Amortization	4,567	3,761
Net Carrying Value	$ 2,077	$ 2,883
Vendor agreements | Minimum
Definite-lived intangible assets
Estimated Useful Lives (years)	8 years	8 years
Vendor agreements | Maximum
Definite-lived intangible assets
Estimated Useful Lives (years)	10 years	10 years
Developed technology
Definite-lived intangible assets
Estimated Useful Lives (years)	5 years	5 years
Weighted Average Amortization Period (in years)	4 years 10 months 24 days	4 years 10 months 24 days
Gross Carrying Amount	$ 5,036	$ 5,209
Accumulated Amortization	1,963	971
Net Carrying Value	$ 3,073	$ 4,238
Leasehold interests
Definite-lived intangible assets
Weighted Average Amortization Period (in years)	7 years 7 months 6 days	7 years 7 months 6 days
Gross Carrying Amount	$ 3,679	$ 3,707
Accumulated Amortization	2,101	1,502
Net Carrying Value	$ 1,578	$ 2,205
Leasehold interests | Minimum
Definite-lived intangible assets
Estimated Useful Lives (years)	1 year	1 year
Leasehold interests | Maximum
Definite-lived intangible assets
Estimated Useful Lives (years)	15 years	15 years
Other intangible assets
Definite-lived intangible assets
Weighted Average Amortization Period (in years)	3 years 4 months 24 days	3 years 4 months 24 days
Gross Carrying Amount	$ 4,157	$ 4,118
Accumulated Amortization	2,447	1,182
Net Carrying Value	$ 1,710	$ 2,936
Other intangible assets | Minimum
Definite-lived intangible assets
Estimated Useful Lives (years)	3 years	3 years
Other intangible assets | Maximum
Definite-lived intangible assets
Estimated Useful Lives (years)	5 years	5 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Intangible assets
Amortization expense	$ 65,201	$ 71,003	$ 41,455
Depreciation and amortization expense
Intangible assets
Amortization expense	$ 65,200	$ 71,000	$ 41,500

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Estimated Aggregate Amortization Expense (Details) $ in Millions	Apr. 30, 2020USD ($)
Estimated aggregate future amortization expense
2021	$ 55.2
2022	46.1
2023	38.3
2024	31.2
2025	25.7
Thereafter	$ 104

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets - Indefinite-Lived Intangible Assets (Details) - USD ($) $ in Millions	Apr. 30, 2020	Apr. 30, 2019
Goodwill and Intangible Assets
Tradenames	$ 61.4	$ 61.4

Other Accrued Expenses and Cu_3

Other Accrued Expenses and Current Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Other Accrued Expenses and Current Liabilities
Insurance related liabilities	$ 12,922	$ 14,110
Customer rebates payable	10,211	7,944
Sales taxes payable	9,493	10,448
Reserve for sales returns	4,081	4,701
Income taxes payable	2,844	14,063
Real estate and personal property taxes	2,182	2,010
Contingent consideration	2,018	13,073
Other	20,061	13,499
Total other accrued expenses and current liabilities	$ 63,812	$ 79,848

Long-Term Debt - Components (De

Long-Term Debt - Components (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Long-term debt
Carrying value of debt	$ 1,097,480	$ 1,141,195
Less current portion	50,201	42,118
Long-term debt	1,047,279	1,099,077
Term Loan Facility
Long-term debt
Carrying value of debt	866,301	972,650
Unamortized discount	1,602	2,149
Deferred financing costs	9,000	12,072
ABL Facility
Long-term debt
Carrying value of debt	80,000	43,972
Finance lease obligations
Long-term debt
Carrying value of debt	128,767	109,286
Installment notes
Long-term debt
Carrying value of debt	15,218	15,287
Unamortized discount	$ 1,098	$ 1,200
Installment notes | Maximum
Long-term debt
Interest rate	5.00%	5.00%
Canadian Facility
Long-term debt
Carrying value of debt	$ 7,194

Long-Term Debt - Acquisition De

Long-Term Debt - Acquisition Debt (Details) $ in Thousands	Mar. 06, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 01, 2018USD ($)	Jun. 07, 2017USD ($)	Apr. 30, 2020USD ($)loan	Apr. 30, 2019USD ($)	Apr. 30, 2018USD ($)
Long-term debt
Loan repayment						$ 571,840	$ 477,616
Write-off of debt discount and deferred financing fees					$ 1,331		74
Term Loan Facility
Long-term debt
Loan repayment			$ 571,800	$ 477,600
Write-off of debt discount and deferred financing fees					$ 1,300
Borrowing interest rate (as a percent)					3.15%
Repayments of debt	$ 50,000	$ 50,000
First Lien Term Loan
Long-term debt
Loan amortization installment frequency					quarterly
Loan amortization installments					$ 2,500
Loan amortization installments (as a percent)					0.25%
First Lien Term Loan | Minimum
Long-term debt
Number of incremental loans | loan					1
First Lien Term Loan | Maximum
Long-term debt
Fixed amount of incremental loan					$ 100,000
Second amendment to First Lien Credit Agreement
Long-term debt
Aggregate principal amount				$ 577,600
Reduction to interest rate margin at each pricing level (as a percent)				0.50%
Write-off of debt discount and deferred financing fees							$ 100
Second amendment to First Lien Credit Agreement | LIBOR
Long-term debt
Margin added to variable rate (as a percent)				3.00%
Variable rate floor (as a percent)				1.00%
Third Amendment
Long-term debt
Aggregate principal amount			$ 996,800
Third Amendment | LIBOR
Long-term debt
Margin added to variable rate (as a percent)			2.75%
Variable rate floor (as a percent)			0.00%
ABL Facility
Long-term debt
Loan repayment					$ 94,000
Borrowing interest rate (as a percent)					1.82%

Long-Term Debt - Asset-Based Le

Long-Term Debt - Asset-Based Lending Facility (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2020	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018	Sep. 30, 2019	Sep. 29, 2019
Long-term debt
Net borrowings		$ 880,698	$ 981,148	$ 513,878
Net repayments		837,424	$ 937,176	$ 617,230
ABL Facility
Long-term debt
Maximum amount under the facility		$ 445,000			$ 445,000	$ 345,000
Borrowing interest rate (as a percent)		1.82%
Net borrowings	$ 80,000
Available borrowings under the facility		$ 353,900
ABL Facility | Swing-line
Long-term debt
Maximum amount under the facility		$ 44,500

Long-Term Debt - Prepayments (D

Long-Term Debt - Prepayments (Details) - Term Loan Facilities $ in Thousands	12 Months Ended
	Apr. 30, 2020USD ($)
Long-term debt
Percentage of the net proceeds of certain asset sales and issuances or incurrences of nonpermitted indebtedness to be used for mandatory prepayments	100.00%
Percentage of annual excess cash flow for mandatory prepayments	50.00%
Prepayment required related to excess cash flow	$ 0
Attainment of certain total leverage ratio targets | Maximum
Long-term debt
Percentage of annual excess cash flow for mandatory prepayments	25.00%
Attainment of certain total leverage ratio targets | Minimum
Long-term debt
Percentage of annual excess cash flow for mandatory prepayments	0.00%

Long-Term Debt - Titan Revolvin

Long-Term Debt - Titan Revolving Credit Facility (Details) $ in Thousands, $ in Millions	1 Months Ended	12 Months Ended
	Mar. 31, 2020USD ($)	Apr. 30, 2020USD ($)	Apr. 30, 2019USD ($)	Apr. 30, 2018USD ($)	Jun. 01, 2018USD ($)	Jun. 01, 2018CAD ($)
Debt Instrument [Line Items]
Net borrowings		$ 880,698	$ 981,148	$ 513,878
Canadian Facility
Debt Instrument [Line Items]
Maximum amount under the facility					$ 21,600	$ 30
Net borrowings	$ 7,200
Available borrowings under the facility		$ 14,400

Long-Term Debt - Installment No

Long-Term Debt - Installment Notes (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Long-term debt
Long term debt	$ 1,097,480	$ 1,141,195
Installment notes
Long-term debt
Long term debt	$ 15,200	$ 15,300

Long-Term Debt - Maturities (De

Long-Term Debt - Maturities (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Debt maturities
2021	$ 50,372
2022	46,953
2023	48,628
2024	31,723
2025	100,770
Thereafter	830,734
Total	1,109,180
First Lien Term Loan
Debt maturities
2021	9,968
2022	9,968
2023	9,968
2024	9,968
2025	9,968
Thereafter	827,063
Total	876,903
Long Term Debt
Unamortized discount	1,602
Term Loan Facility
Long Term Debt
Unamortized discount	1,602	$ 2,149
Deferred financing costs	9,000	12,072
ABL Facility
Debt maturities
2025	80,000
Total	80,000
Finance lease obligations
Debt maturities
2021	35,530
2022	32,547
2023	27,062
2024	19,974
2025	9,983
Thereafter	3,671
Total	128,767
Installment notes
Debt maturities
2021	4,874
2022	4,438
2023	4,404
2024	1,781
2025	819
Total	16,316
Long Term Debt
Unamortized discount	1,098	$ 1,200
Canadian Facility
Debt maturities
2023	7,194
Total	7,194
Installment notes
Long Term Debt
Unamortized discount	$ 1,098

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Leases
Option to extend	true
Finance lease cost:
Amortization of right-of-use assets	$ 24,352
Interest on lease liabilities	13,316
Operating lease cost	42,846
Variable lease cost	12,555
Total lease cost	$ 93,069
Rent expense		$ 53,500	$ 63,900
Minimum
Leases
Lease term (in years)	1 year
Renewal lease term (in years)	1 year
Maximum
Leases
Lease term (in years)	11 years
Renewal lease term (in years)	5 years

Leases - Supplemental cash flow

Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 42,150
Operating cash flows from finance leases	13,316
Financing cash flows from finance leases	25,275	$ 19,474	$ 6,132
Right-of-use assets obtained in exchange for lease obligations - Operating leases	38,143
Right-of-use assets obtained in exchange for lease obligations - Finance leases	$ 50,484

Leases - Other information (Det

Leases - Other information (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Finance leases included in property and equipment
Property and equipment	$ 464,021	$ 405,932
Accumulated depreciation	(158,554)	(123,583)
Property and equipment, net	$ 305,467	282,349
Weighted-average remaining lease term (years) - Operating leases	4 years 10 months 24 days
Weighted-average remaining lease term (years) - Finance leases	3 years 7 months 6 days
Weighted-average discount rate - Operating leases	5.50%
Weighted-average discount rate - Finance leases	5.00%
Finance Leased Assets
Finance leases included in property and equipment
Property and equipment	$ 171,380	134,931
Accumulated depreciation	(41,737)	(27,686)
Property and equipment, net	$ 129,643	$ 107,245

Leases - Future minimum lease p

Leases - Future minimum lease payments under non-cancellable leases (Details) $ in Thousands	Apr. 30, 2020USD ($)
Finance lease
2021	$ 46,116
2022	39,328
2023	30,525
2024	21,234
2025	10,544
Thereafter	3,647
Total lease payments	151,394
Less imputed interest	22,627
Total	128,767
Operating lease
2021	38,960
2022	30,387
2023	23,655
2024	18,775
2025	12,154
Thereafter	16,848
Total lease payments	140,779
Less imputed interest	18,134
Total	$ 122,645

Retirement Plan (Details)

Retirement Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Retirement Plan
Employee contributions matched by employer (as a percent)	50.00%
Employee compensation eligible for employer match of employee contributions (as a percent)	4.00%
Employer contributions to defined contribution retirement plan	$ 5.3	$ 4.7	$ 4.3

Income Taxes - Components of in

Income Taxes - Components of income before taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Income before taxes	$ 46,325	$ 70,041	$ 83,854
Domestic
Income before taxes	106,850	62,878	$ 83,854
Foreign
Income before taxes	$ (60,525)	$ 7,163

Income Taxes - Components of _2

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Components of income tax expense (benefit)
Current federal	$ 12,537	$ 11,858	$ 30,827
Current foreign	1,624	13,739
Current state	7,857	5,929	6,409
Total current	22,018	31,526	37,236
Deferred federal	8,986	453	(14,796)
Deferred foreign	(7,347)	(16,931)
Deferred state	(713)	(1,009)	(1,557)
Total deferred	926	(17,487)	(16,353)
Total provision for income taxes	$ 22,944	$ 14,039	$ 20,883

Income Taxes - Reconciliation t

Income Taxes - Reconciliation to Federal Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Income tax expense (benefit) differences to amount computed by applying federal statutory rate
Federal income taxes at statutory rate	$ 9,747	$ 14,715	$ 25,492
State income taxes, net of federal income tax benefit	4,054	2,440	1,900
Impact of foreign rate differences	(2,861)	418
Impact of rate difference on impairment of goodwill	7,630
Net change in valuation allowance	9,070	664	151
Nondeductible meals & entertainment	592	635	822
Equity-based compensation	(1,196)	(53)
GILTI	704	241
Nondeductible transaction costs	90	529	2
Net deferred benefit due to Tax Cuts and Jobs Act			(6,763)
Intercompany interest expense	(5,361)	(5,255)
Other	475	(295)	(721)
Total provision for income taxes	$ 22,944	$ 14,039	$ 20,883

Income Taxes - Deferred Income

Income Taxes - Deferred Income Taxes (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Deferred income tax assets:
Allowances on accounts and notes receivable	$ 2,016	$ 2,306
Accrued payroll and related costs	1,859	1,577
Insurance reserves	2,501	1,746
Inventory costs	2,630	2,066
Deferred compensation	7,426	6,854
Equity compensation	2,695	2,944
Derivative instrument	7,850	1,358
Acquisition related costs	1,311	1,779
Net operating loss carry-forwards	1,595	1,745
Disallowed interest expense	736	2,507
Investment in partnerships	16,535	4,676
Deferred rent	1,112	604
Noncompete agreements	120	133
Other deferred tax assets, net	1,424	1,394
Total deferred income tax assets	49,810	31,689
Less: Valuation allowance	(10,183)	(1,112)
Total deferred income tax assets, net of valuation allowance	39,627	30,577
Deferred income tax liabilities:
Amortization of intangible assets	(18,917)	(22,950)
Rebates	(400)	(72)
Depreciation	(21,508)	(10,495)
Deferred financing costs	(1,582)	(2,075)
Other deferred tax liabilities, net	(334)	(535)
Total deferred income tax liabilities	(42,741)	(36,127)
Deferred income tax liabilities, net	$ (3,114)	$ (5,550)

Income Taxes - Tax Act (Details

Income Taxes - Tax Act (Details) - USD ($) $ in Millions	8 Months Ended	9 Months Ended	12 Months Ended	28 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Apr. 30, 2019	Apr. 30, 2020
Income Taxes
Federal statutory rate (as a percent)	35.00%			21.00%
Provisional income tax benefit			$ 6.7
Decrease from provisional amount		$ (1.1)
Income tax benefit related to tax adjustment			$ 0.1

Income Taxes - Net Operating Lo

Income Taxes - Net Operating Loss Carryforwards and Valuation Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Operating loss carryforwards
Net operating loss carry forwards		$ 700	$ 2,300
Valuation allowance
Valuation allowance	$ 10,183	1,112
Valuation allowance increase (decrease)	$ 7,600
State
Operating loss carryforwards
Net operating loss carry forwards		$ 27,400	$ 23,100

Income Taxes - Uncertain tax po

Income Taxes - Uncertain tax positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Income tax examinations
Reserve for uncertain tax positions	$ 0	$ 0
Liability for uncertain tax position	$ 0	$ 0
State | Minimum
Income tax examinations
Statute of limitation period	3 years
State | Maximum
Income tax examinations
Statute of limitation period	4 years

Stockholders' Equity - Exchange

Stockholders' Equity - Exchangeable Shares, Share Repurchase Program and Secondary Public Offering (Details) $ / shares in Units, shares in Millions, $ in Millions	Sep. 09, 2019$ / sharesshares	Jun. 13, 2019shares	Nov. 30, 2018USD ($)	Jun. 01, 2018shares	Apr. 30, 2019USD ($)shares	Apr. 30, 2020USD ($)
Exchangeable Shares and Share Repurchase Program
Number of shares repurchased					1
Shares repurchased, cost | $					$ 16.5
Remaining amount under repurchase program | $						$ 58.5
AEA Investors LP | Selling Stockholders
Exchangeable Shares and Share Repurchase Program
Shares sold	6.8
Price to the public (in dollars per share) | $ / shares	$ 27.20
Maximum
Exchangeable Shares and Share Repurchase Program
Shares repurchased, cost | $			$ 75
Titan
Exchangeable Shares and Share Repurchase Program
Issuance of shares to current shareholders of Titan (in shares)				1.1
Exchangeable shares converted		1.1
Exchangeable shares conversion ratio				1
Duration which stock can not be transferred				1 year

Stockholders' Equity - Accumula

Stockholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Accumulated other comprehensive (loss) income
Balance	$ 629,176	$ 579,451	$ 514,606
Balance	633,981	629,176	579,451
Other comprehensive loss on derivative instruments before reclassification, tax	6,400	1,400
Accumulated Other Comprehensive Income (Loss)
Accumulated other comprehensive (loss) income
Balance	(26,574)	441	(884)
Other comprehensive (loss) income before reclassification	(38,508)	(27,743)	309
Reclassification to earnings from accumulated other comprehensive (loss) income		728	1,016
Balance	(65,082)	(26,574)	441
Foreign Currency Translation
Accumulated other comprehensive (loss) income
Balance	(22,320)
Other comprehensive (loss) income before reclassification	(18,257)	(22,320)
Balance	(40,577)	(22,320)
Derivative Financial Instruments
Accumulated other comprehensive (loss) income
Balance	(4,254)	441	(884)
Other comprehensive (loss) income before reclassification	(20,251)	(5,423)	309
Reclassification to earnings from accumulated other comprehensive (loss) income		728	1,016
Balance	$ (24,505)	$ (4,254)	$ 441

Equity-Based Compensation (Deta

Equity-Based Compensation (Details) shares in Millions	12 Months Ended
	Apr. 30, 2020shares
Stock Options
Stock options
Term of award	ten years
Minimum | Stock Options
Stock options
Vesting period (in years)	3 years
Minimum | Restricted stock units
Stock options
Vesting period (in years)	1 year
Maximum | Stock Options
Stock options
Vesting period (in years)	4 years
Maximum | Restricted stock units
Stock options
Vesting period (in years)	3 years
Plan
Stock options
Shares authorized	2.5
Number of shares available for grant	1.2

Equity-Based Compensation - Sto

Equity-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Other disclosures
Equity-based compensation	$ 7,060	$ 3,906	$ 1,695
Selling, general and administrative expenses
Other disclosures
Equity-based compensation	$ 6,500	$ 3,600	1,700
Stock Options
Number of Options
Outstanding, beginning of the period (in shares)	2,080
Options granted (in shares)	386
Options exercised (in shares)	(874)
Options forfeited (in shares)	(105)
Outstanding, end of the period (in shares)	1,487	2,080
Exercisable at end of period (in shares)	941
Vested and expected to vest at end of period (in shares)	1,481
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 16.34
Options granted (in dollars per share)	21.63
Options exercised (in dollars per share)	13.22
Options forfeited (in dollars per share)	25.73
Outstanding, end of the period (in dollars per share)	18.85	$ 16.34
Exercisable at end of period (in dollars per share)	16.32
Vested and expected to vest at end of period (in dollars per share)	$ 18.83
Other disclosures
Weighted Average Remaining Contractual Life, Outstanding (in years)	6 years 4 months 24 days	6 years 1 month 24 days
Weighted Average Remaining Contractual Life, Exercisable at end of period (in years)	4 years 11 months 23 days
Weighted Average Remaining Contractual Life, Vested and expected to vest at end of period (in years)	6 years 4 months 20 days
Aggregate Intrinsic Value, Outstanding	$ 3,895	$ 7,615
Aggregate Intrinsic Value, Exercisable at end of period	3,866
Aggregate Intrinsic Value, Vested and expected to vest at end of period	3,895
Intrinsic value of options exercised	11,500	$ 1,600	$ 4,300
Unrecognized compensation cost	$ 3,600
Weighted-average period for recognition of unrecognized compensation expense (in years)	1 year 10 months 24 days

Equity-Based Compensation - Bla

Equity-Based Compensation - Black Scholes Options - Pricing Model (Details) - Stock Options - $ / shares	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Stock options
Volatility (as a percent)	49.86%	33.71%	30.86%
Expected life (years)	6 years	6 years	6 years
Risk-free interest rate (as a percent)	1.97%	2.87%	2.18%
Dividend yield (as a percent)	0.00%	0.00%	0.00%
Weighted average grant date fair value (in dollars per share)	$ 10.59	$ 9.72	$ 12.81

Equity-Based Compensation - Res

Equity-Based Compensation - Restricted Stock Units (Details) - Restricted stock units $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Apr. 30, 2020USD ($)$ / sharesshares
Number of Restricted Stock Units
Outstanding, beginning of the period (in shares) | shares	193
Granted (in shares) | shares	233
Vested (in shares) | shares	(100)
Forfeited (in shares) | shares	(40)
Outstanding, end of the period (in shares) | shares	286
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 25.48
Granted (in dollars per share) | $ / shares	21.67
Vested (in dollars per share) | $ / shares	24.48
Forfeited (in dollars per share) | $ / shares	25.29
Outstanding, end of the period (in dollars per share) | $ / shares	$ 22.71
Unrecognized compensation cost | $	$ 3.8
Weighted-average period for recognition of unrecognized compensation expense (in years)	1 year 9 months 18 days

Equity-Based Compensation - Emp

Equity-Based Compensation - Employee Stock Purchase Plan (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 7,060	$ 3,906	$ 1,695
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of common stock price based on closing price at the beginning or end of the last day of the purchase period			90.00%
Purchase period			6 months
Number of shares authorized			2
Number of shares available for issuance	1.8
Number of shares purchased under ESPP	0.1	0.1
Average price per share	$ 15.62	$ 18.51
Share-based compensation expense	$ 500	$ 300	$ 100

Stock Appreciation Rights, De_3

Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Selling, general and administrative expenses
Equity based compensation arrangements
Expense related to equity based compensation arrangements	$ 2,100	$ 3,900	$ 4,000
Stock Appreciation Rights
Equity based compensation arrangements
Award liability as of beginning of period	23,458	21,944
Amounts redeemed	(825)	(1,216)
Change in fair value	1,572	2,730
Award liability as of end of period	24,205	23,458	21,944
Current liabilities related to plans	624	1,355
Long-term liabilities related to plans	$ 23,581	22,103
Settlement period	5 years
Deferred Compensation
Equity based compensation arrangements
Award liability as of beginning of period	$ 1,695	2,222
Amounts redeemed	(108)	(715)
Change in fair value	73	188
Award liability as of end of period	1,660	1,695	2,222
Current liabilities related to plans		108
Long-term liabilities related to plans	$ 1,660	1,587
Settlement period	5 years
Redeemable Noncontrolling Interests
Equity based compensation arrangements
Award liability as of beginning of period	$ 12,498	16,170
Amounts redeemed	(4,644)	(4,673)
Change in fair value	446	1,001
Award liability as of end of period	8,300	12,498	$ 16,170
Current liabilities related to plans		1,569
Long-term liabilities related to plans	$ 8,300	$ 10,929
Settlement period	5 years

Derivative Instruments (Details

Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jul. 31, 2018	Apr. 30, 2019	Apr. 30, 2018	Feb. 28, 2019
Derivative [Line Items]
Change in fair value of financial instruments	$ (5,700)	$ (6,395)	$ (6,125)
Interest rate swap agreements
Derivative [Line Items]
Notional amount				$ 500,000
Interest rate swap agreements | Term Loan Facility | LIBOR
Derivative [Line Items]
Capped interest rate (as a percent)				2.46%
Foreign currency forward contract
Derivative [Line Items]
Change in fair value of financial instruments		$ (5,700)	$ (5,100)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Fair Value Measurements
Contingent consideration expense		$ 1,800	$ 800
Impairment of goodwill	$ 63,100	63,074
Impairment charges	1,900	0	0	$ 0
Fair Value, Measurements, Recurring | Level 3
Fair Value Measurements
Stock appreciation rights	24,205	24,205	23,458
Deferred compensation	1,660	1,660	1,695
Noncontrolling interest holders	8,300	8,300	12,498
Contingent consideration			12,354
Interest rate swap agreements | Fair Value, Measurements, Recurring | Level 2
Fair Value Measurements
Derivative liabilities	32,218	32,218	$ 5,613
Titan
Fair Value Measurements
Assumed contingent consideration arrangements	$ 12,400	$ 12,400

Transactions With Related Par_2

Transactions With Related Parties - Facilities Rental (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Transactions with related parties
Aggregate future minimum payments due	$ 140,779
Affiliated partnerships or entities | Lease of warehouse facilities
Transactions with related parties
Aggregate future minimum payments due	1,200
Affiliated partnerships or entities | Lease of warehouse facilities | Selling, general and administrative expenses
Transactions with related parties
Rent expense	$ 800	$ 800	$ 800

Transactions With Related Par_3

Transactions With Related Parties - Purchased Inventories (Details) - Southern Wall Products, Inc. - Inventory purchases - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Transactions with related parties
Purchases from related party	$ 14.3	$ 13.3	$ 14
Accounts payable
Transactions with related parties
Due to SWP	$ 1.2	$ 1.2

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2020
Commitments and Contingencies
Gain on legal settlement	$ 14,000	$ 14,029

Segments (Details)

Segments (Details)	12 Months Ended
	Apr. 30, 2020segment
Segments
Number of operating segments	7
Number of reportable segments	1
Number of geographic divisions	7

Segments - Net Sales, Adjusted

Segments - Net Sales, Adjusted EBITDA and Certain Other Measures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Segment information
Net sales	$ 770,850	$ 761,352	$ 861,929	$ 847,176	$ 780,149	$ 723,902	$ 833,837	$ 778,144	$ 3,241,307	$ 3,116,032	$ 2,511,469
Gross Profit	251,594	$ 253,473	$ 284,493	$ 273,654	256,927	$ 234,226	$ 268,150	$ 244,816	1,063,214	1,004,119	818,576
Depreciation and Amortization									116,533	117,459	65,530
Adjusted EBITDA									299,759	295,669	199,258
Total assets	2,288,782				2,149,554				2,288,782	2,149,554	1,454,511
Geographic divisions
Segment information
Net sales									3,213,938	3,090,314	2,487,557
Gross Profit									1,053,555	994,981	809,884
Depreciation and Amortization									114,279	114,558	64,491
Adjusted EBITDA									297,646	293,190	196,903
Total assets	2,264,208				2,125,518				2,264,208	2,125,518	1,434,371
Other.
Segment information
Net sales									27,369	25,718	23,912
Gross Profit									9,659	9,138	8,692
Depreciation and Amortization									233	220	242
Adjusted EBITDA									2,113	2,479	2,355
Total assets	18,745				16,897				18,745	16,897	12,854
Corporate
Segment information
Depreciation and Amortization									2,021	2,681	797
Total assets	$ 5,829				$ 7,139				$ 5,829	$ 7,139	$ 7,286

Segments - Reconciliation of Ne

Segments - Reconciliation of Net Income to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Segments
Net income	$ (41,456)	$ 10,879	$ 29,138	$ 24,820	$ 16,625	$ 5,815	$ 24,912	$ 8,650	$ 23,381	$ 56,002	$ 62,971
Interest expense									67,718	73,677	31,395
Write-off of debt discount and deferred financing fees									1,331		74
Interest income									(88)	(66)	(177)
Provision for income taxes									22,944	14,039	20,883
Depreciation expense									51,332	46,456	24,075
Amortization expense									65,201	71,003	41,455
Impairment of goodwill	63,100								63,074
Stock appreciation expense									1,572	2,730	2,318
Redeemable noncontrolling interests									520	1,188	1,868
Equity-based compensation									7,060	3,906	1,695
Severance and other permitted costs									5,733	8,152	581
Transaction costs (acquisitions and other)									2,414	7,858	3,370
Loss (gain) on disposal and impairment of assets									658	(525)	(509)
Effects of fair value adjustments to inventory									575	4,176	324
Change in fair value of financial instruments								$ 5,700		6,395	6,125
Gain on legal settlement	(14,000)								(14,029)
Secondary public offering costs									363		1,525
Debt transaction costs										678	1,285
Adjusted EBITDA									299,759	$ 295,669	$ 199,258
Impairment	$ 1,900								$ 1,900

Segments - Net Sales by Main Pr

Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Revenue from external customers
Total net sales	$ 770,850	$ 761,352	$ 861,929	$ 847,176	$ 780,149	$ 723,902	$ 833,837	$ 778,144	$ 3,241,307	$ 3,116,032	$ 2,511,469
Wallboard
Revenue from external customers
Total net sales									1,329,775	1,272,068	1,109,552
Ceilings
Revenue from external customers
Total net sales									475,827	451,695	387,360
Steel framing
Revenue from external customers
Total net sales									502,122	506,805	411,630
Other products
Revenue from external customers
Total net sales									$ 933,583	$ 885,464	$ 602,927

Segments - Net sales by major g

Segments - Net sales by major geographic area (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$ 770,850	$ 761,352	$ 861,929	$ 847,176	$ 780,149	$ 723,902	$ 833,837	$ 778,144	$ 3,241,307	$ 3,116,032	$ 2,511,469
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									2,805,920	2,701,678	$ 2,511,469
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales									$ 435,387	$ 414,354

Segments - Property and equipme

Segments - Property and equipment, net, by major geographic area (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 305,467	$ 282,349
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	270,855	249,857
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 34,612	$ 32,492

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020		Apr. 30, 2019		Apr. 30, 2018
Computation of basic and diluted earnings per share of common stock
Net income	$ (41,456)	$ 10,879	$ 29,138	$ 24,820	$ 16,625	$ 5,815	$ 24,912	$ 8,650	$ 23,381		$ 56,002		$ 62,971
Less: Net income allocated to participating securities									74		1,382
Net income attributable to common stockholders									$ 23,307		$ 54,620		$ 62,971
Basic earnings per common share:
Basic weighted average common shares outstanding (in shares)	42,435	42,223	41,761	41,001	40,487	40,912	41,149	41,094	41,853		40,914		41,015
Basic earnings per common share (in dollars per share)	$ (0.98)	$ 0.26	$ 0.70	$ 0.60	$ 0.40	$ 0.14	$ 0.59	$ 0.21	$ 0.56	[1]	$ 1.33	[1]	$ 1.54	[1]
Diluted earnings per common share:
Basic weighted average common shares outstanding (in shares)	42,435	42,223	41,761	41,001	40,487	40,912	41,149	41,094	41,853		40,914		41,015
Add: Common Stock Equivalents									651		675		1,148
Diluted weighted average common shares outstanding (in shares)	42,435	42,949	42,635	41,615	40,976	41,371	41,918	42,074	42,504		41,589		42,163
Diluted earnings per common share (in dollars per share)	$ (0.98)	$ 0.25	$ 0.68	$ 0.59	$ 0.39	$ 0.14	$ 0.58	$ 0.20	$ 0.55	[1]	$ 1.31	[1]	$ 1.49	[1]
Shares were not included in the calculation of Diluted loss per common share
Anti-dilutive shares									800		600
[1]	See Note 19 for detailed calculations.

Valuation and Qualifying Acco_3

Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018
Allowances for Accounts Receivable
Allowance Rollforward
Balance at beginning of period	$ (6,432)	$ (9,633)	$ (9,851)
Provision / Additions charged to costs and expenses	(2,348)	(1,064)	(366)
Charged to other accounts	938	2,435	(596)
Deductions	2,701	1,830	1,180
Balance at end of period	(5,141)	(6,432)	(9,633)
Valuation Allowance on Deferred Tax Assets
Allowance Rollforward
Balance at beginning of period	(1,112)	(448)	(297)
Provision / Additions charged to costs and expenses	(9,071)	(664)	(151)
Balance at end of period	$ (10,183)	$ (1,112)	$ (448)

Valuation and Qualifying Acco_4

Valuation and Qualifying Accounts - Reclassification (Details) - USD ($) $ in Thousands	Apr. 30, 2020	Apr. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Trade accounts and notes receivable	$ 405,254	$ 445,771
Other accrued expenses and current liabilities	63,812	79,848
ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Trade accounts and notes receivable	$ (3,600)
Other accrued expenses and current liabilities		$ (3,600)

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020		Apr. 30, 2019		Apr. 30, 2018
Selected Quarterly Financial Data (Unaudited)
Net sales	$ 770,850	$ 761,352	$ 861,929	$ 847,176	$ 780,149	$ 723,902	$ 833,837	$ 778,144	$ 3,241,307		$ 3,116,032		$ 2,511,469
Gross Profit	251,594	253,473	284,493	273,654	256,927	234,226	268,150	244,816	1,063,214		1,004,119		818,576
Net income (loss)	$ (41,456)	$ 10,879	$ 29,138	$ 24,820	$ 16,625	$ 5,815	$ 24,912	$ 8,650	$ 23,381		$ 56,002		$ 62,971
Weighted average shares outstanding:
Basic (in shares)	42,435	42,223	41,761	41,001	40,487	40,912	41,149	41,094	41,853		40,914		41,015
Diluted (in shares)	42,435	42,949	42,635	41,615	40,976	41,371	41,918	42,074	42,504		41,589		42,163
Net income per share:
Basic (in dollars per share)	$ (0.98)	$ 0.26	$ 0.70	$ 0.60	$ 0.40	$ 0.14	$ 0.59	$ 0.21	$ 0.56	[1]	$ 1.33	[1]	$ 1.54	[1]
Diluted (in dollars per share)	$ (0.98)	$ 0.25	$ 0.68	$ 0.59	$ 0.39	$ 0.14	$ 0.58	$ 0.20	$ 0.55	[1]	$ 1.31	[1]	$ 1.49	[1]
Impairment of goodwill	$ 63,100								$ 63,074
Gain on legal settlement	$ 14,000								$ 14,029
Change in fair value of financial instruments								$ (5,700)			$ (6,395)		$ (6,125)
[1]	See Note 19 for detailed calculations.