GMS (GMS) 10-Q 3 Dec 20 2021 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Oct. 31, 2020	Nov. 30, 2020
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Oct. 31, 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
Trading Symbol	GMS
Security Exchange Name	NYSE
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 Common Stock, Shares Outstanding		42,681,068
Entity Central Index Key	0001600438
Current Fiscal Year End Date	--04-30
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Current assets:
Cash and cash equivalents	$ 118,168	$ 210,909
Trade accounts and notes receivable, net of allowances of $5,273 and $5,141, respectively	434,836	405,254
Inventories, net	302,357	299,815
Prepaid expenses and other current assets	19,042	14,972
Total current assets	874,403	930,950
Property and equipment, net of accumulated depreciation of $174,832 and $158,554, respectively	300,144	305,467
Operating lease right-of-use assets	114,198	115,257
Goodwill	557,486	553,073
Intangible assets, net	339,918	361,884
Deferred income taxes	12,651	8,904
Other assets	12,074	13,247
Total assets	2,210,874	2,288,782
Current liabilities:
Accounts payable	163,927	213,230
Accrued compensation and employee benefits	43,843	67,590
Other accrued expenses and current liabilities	88,170	63,812
Current portion of long-term debt	49,302	50,201
Current portion of operating lease liabilities	31,694	33,040
Total current liabilities	376,936	427,873
Non-current liabilities:
Long-term debt, less current portion	946,721	1,047,279
Long-term operating lease liabilities	88,122	89,605
Deferred income taxes, net	7,837	12,018
Other liabilities	73,361	78,026
Total liabilities	1,492,977	1,654,801
Commitments and contingencies
Stockholders' equity:
Common stock, par value $0.01 per share, 500,000 shares authorized; 42,690 and 42,554 shares issued and outstanding as of October 31, 2020 and April 30, 2020, respectively	427	426
Preferred stock, par value $0.01 per share, 50,000 shares authorized; 0 shares issued and outstanding as of October 31, 2020 and April 30, 2020
Additional paid-in capital	534,646	529,662
Retained earnings	224,663	168,975
Accumulated other comprehensive loss	(41,839)	(65,082)
Total stockholders' equity	717,897	633,981
Total liabilities and stockholders' equity	$ 2,210,874	$ 2,288,782

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Condensed Consolidated Balance Sheets
Trade accounts and notes receivable, allowances (in dollars)	$ 5,273	$ 5,141
Property and equipment, accumulated depreciation (in dollars)	$ 174,832	$ 158,554
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	500,000	500,000
Common stock, shares issued	42,690	42,554
Common stock, shares outstanding	42,690	42,554
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000	50,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Condensed Consolidated Statements of Operations and Comprehensive Income
Net sales		$ 812,856	$ 861,929	$ 1,615,429	$ 1,709,105
Cost of sales (exclusive of depreciation and amortization shown separately below)		547,785	577,436	1,089,900	1,150,958
Gross profit		265,071	284,493	525,529	558,147
Operating expenses:
Selling, general and administrative		188,352	200,457	371,464	395,088
Depreciation and amortization		27,245	29,518	54,342	58,793
Total operating expenses		215,597	229,975	425,806	453,881
Operating income		49,474	54,518	99,723	104,266
Other (expense) income:
Interest expense		(13,525)	(17,559)	(27,606)	(35,836)
Write-off of debt discount and deferred financing fees			(707)		(707)
Other income, net		797	813	1,452	1,752
Total other expense, net		(12,728)	(17,453)	(26,154)	(34,791)
Income before taxes		36,746	37,065	73,569	69,475
Provision for income taxes		8,277	7,927	17,881	15,517
Net income		$ 28,469	$ 29,138	$ 55,688	$ 53,958
Weighted average common shares outstanding:
Basic (in shares)		42,723	41,761	42,674	41,382
Diluted (in shares)		43,174	42,635	43,096	42,126
Net income per common share:
Basic (in dollars per share)	[1]	$ 0.67	$ 0.70	$ 1.30	$ 1.30
Diluted (in dollars per share)	[1]	$ 0.66	$ 0.68	$ 1.29	$ 1.27
Comprehensive income
Net income		$ 28,469	$ 29,138	$ 55,688	$ 53,958
Foreign currency translation income (loss)		3,159	(409)	19,440	11,451
Changes in other comprehensive income (loss), net of tax		2,844	(3,602)	3,803	(9,667)
Comprehensive income		$ 34,472	$ 25,127	$ 78,931	$ 55,742
[1]	See Note 15 for detailed calculations .

Condensed Consolidated Statem_2

Condensed 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 Loss	Total
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
Increase (Decrease) in Stockholders' Equity
Net income				24,820		24,820
Exercise of Exchangeable Shares	$ 11	(29,639)	29,628
Exercise of Exchangeable Shares (in shares)	1,129
Foreign currency translation adjustments					11,860	11,860
Change in other comprehensive income (loss), net of tax					(6,065)	(6,065)
Equity-based compensation			1,349			1,349
Exercise of stock options			133			133
Exercise of stock options (in shares)	9
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,021			1,022
Issuance of common stock pursuant to employee stock purchase plan (in shares)	76
Balance at Jul. 31, 2019	$ 416		512,244	170,414	(20,779)	662,295
Balance (in shares) at Jul. 31, 2019	41,589
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
Increase (Decrease) in Stockholders' Equity
Net income						53,958
Foreign currency translation adjustments						11,451
Balance at Oct. 31, 2019	$ 422		520,855	199,552	(24,790)	696,039
Balance (in shares) at Oct. 31, 2019	42,169
Balance at Jul. 31, 2019	$ 416		512,244	170,414	(20,779)	662,295
Balance (in shares) at Jul. 31, 2019	41,589
Increase (Decrease) in Stockholders' Equity
Net income				29,138		29,138
Foreign currency translation adjustments					(409)	(409)
Change in other comprehensive income (loss), net of tax					(3,602)	(3,602)
Equity-based compensation			2,271			2,271
Exercise of stock options	$ 5		6,623			6,628
Exercise of stock options (in shares)	525
Vesting of restricted stock units	$ 1		(1)
Vesting of restricted stock units (in shares)	55
Tax withholding related to net share settlements of stock options/equity awards			(282)			(282)
Balance at Oct. 31, 2019	$ 422		520,855	199,552	(24,790)	696,039
Balance (in shares) at Oct. 31, 2019	42,169
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
Increase (Decrease) in Stockholders' Equity
Net income				27,219		$ 27,219
Foreign currency translation adjustments					16,281	16,281
Change in other comprehensive income (loss), net of tax					959	959
Equity-based compensation			1,575			1,575
Exercise of stock options			691			691
Exercise of stock options (in shares)	54
Vesting of restricted stock units (in shares)	7
Tax withholding related to net share settlements of stock options/equity awards			(105)			(105)
Issuance of common stock pursuant to employee stock purchase plan	$ 1		1,269			1,270
Issuance of common stock pursuant to employee stock purchase plan (in shares)	58
Balance at Jul. 31, 2020	$ 427		533,092	196,194	(47,842)	681,871
Balance (in shares) at Jul. 31, 2020	42,673
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
Increase (Decrease) in Stockholders' Equity
Net income						$ 55,688
Foreign currency translation adjustments						19,440
Balance at Oct. 31, 2020	$ 427		534,646	224,663	(41,839)	$ 717,897
Balance (in shares) at Oct. 31, 2020	42,690					42,690
Balance at Jul. 31, 2020	$ 427		533,092	196,194	(47,842)	$ 681,871
Balance (in shares) at Jul. 31, 2020	42,673
Increase (Decrease) in Stockholders' Equity
Net income				28,469		28,469
Foreign currency translation adjustments					3,159	3,159
Change in other comprehensive income (loss), net of tax					2,844	2,844
Repurchase and retirement of common stock	$ (1)		(1,221)			(1,222)
Repurchase and retirement of common stock (in shares)	(50)
Equity-based compensation			3,253			3,253
Exercise of stock options			172			172
Exercise of stock options (in shares)	5
Vesting of restricted stock units	$ 1		(1)
Vesting of restricted stock units (in shares)	62
Tax withholding related to net share settlements of stock options/equity awards			(649)			(649)
Balance at Oct. 31, 2020	$ 427		$ 534,646	$ 224,663	$ (41,839)	$ 717,897
Balance (in shares) at Oct. 31, 2020	42,690					42,690

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Cash flows from operating activities:
Net income	$ 55,688	$ 53,958
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	54,342	58,793
Write-off and amortization of debt discount and debt issuance costs	1,505	2,368
Equity-based compensation	6,370	5,591
Loss (gain) on disposal and impairment of assets	875	(742)
Deferred income taxes	(9,296)	(2,380)
Other items, net	(1,057)	1,101
Changes in assets and liabilities net of effects of acquisitions:
Trade accounts and notes receivable	(26,137)	(29,932)
Inventories	(950)	1,800
Prepaid expenses and other assets	(4,776)	1,573
Accounts payable	(50,867)	(5,486)
Accrued compensation and employee benefits	(23,889)	(12,974)
Other accrued expenses and liabilities	22,240	(3,743)
Cash provided by operating activities	24,048	69,927
Cash flows from investing activities:
Purchases of property and equipment	(11,845)	(14,637)
Proceeds from sale of assets	720	1,056
Acquisition of businesses, net of cash acquired	(51)	(10,633)
Cash used in investing activities	(11,176)	(24,214)
Cash flows from financing activities:
Repayments on revolving credit facilities	(102,189)	(558,906)
Borrowings from revolving credit facilities	14,750	562,698
Payments of principal on long-term debt	(4,984)	(54,984)
Payments of principal on finance lease obligations	(14,629)	(12,310)
Repurchases of common stock	(1,222)
Debt issuance costs		(1,286)
Proceeds from exercises of stock options	863	6,761
Payments for taxes related to net share settlement of equity awards	(754)
Other financing activities	1,270	1,022
Cash used in financing activities	(106,895)	(57,005)
Effect of exchange rates on cash and cash equivalents	1,282	223
Decrease in cash and cash equivalents	(92,741)	(11,069)
Cash and cash equivalents, beginning of period	210,909	47,338
Cash and cash equivalents, end of period	118,168	36,269
Supplemental cash flow disclosures:
Cash paid for income taxes	20,224	25,642
Cash paid for interest	$ 25,726	$ 33,654

Business, Basis of Presentation

Business, Basis of Presentation and Summary of Significant Accounting Policies	6 Months Ended
	Oct. 31, 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 approximately 260 distribution centers across the United States and Canada. ​ Basis of Presentation ​ The condensed consolidated financial statements included in this Quarterly Report on Form 10-Q have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) that permit reduced disclosure for interim periods. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all normal and recurring adjustments necessary for a fair presentation of the results of operations, financial position and cash flows. All adjustments are of a normal recurring nature unless otherwise disclosed. The results of operations for interim periods are not necessarily indicative of results for any other interim period or the entire fiscal year. As a result, the unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended April 30, 2020. ​ Principles of Consolidation ​ The condensed consolidated financial statements present the results of operations, financial position, stockholders’ equity and cash flows of the Company and its subsidiaries. All material intercompany balances and transactions have been eliminated in consolidation. The results of operations of businesses acquired are included from their respective dates of acquisition. ​ Use of Estimates ​ The preparation of financial statements in conformity with 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 as of 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. Gains and losses on foreign currency transactions are recognized in the Condensed Consolidated Statements of Operations and Comprehensive Income within other (expense) income, net. ​ 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 October 31, 2020 and April 30, 2020, the aggregate liabilities for medical self-insurance were $4.2 million and $3.8 million, respectively, and are included in other accrued expenses and current liabilities in the Condensed Consolidated Balance Sheets. As of October 31, 2020 and April 30, 2020, reserves for general liability, automobile and workers’ compensation totaled approximately $20.1 million and $19.4 million, respectively, and are included in other accrued expenses and current liabilities and other liabilities in the Condensed Consolidated Balance Sheets. As of October 31, 2020 and April 30, 2020, expected recoveries for medical self-insurance, general liability, automobile and workers’ compensation totaled approximately $8.0 million and $6.0 million, respectively, and are included in prepaid expenses and other current assets and other assets in the Condensed Consolidated Balance Sheets. ​ Income Taxes ​ The Company considers each interim period an integral part of the annual period and measures tax expense (benefit) using an estimated annual effective income tax rate. Estimates of the annual effective income tax rate at the end of interim periods are, out of necessity, based on evaluation of possible future events and transactions and may be subject to subsequent refinement or revision. The Company forecasts its estimated annual effective income tax rate and then applies that rate to its year-to-date pre-tax ordinary income (loss), subject to certain loss limitation provisions. In addition, certain specific transactions are excluded from the Company’s estimated annual effective tax rate computation, but are discretely recognized within income tax expense (benefit) in their respective interim period. Future changes in the forecasted annual income (loss) projections, tax rate changes, or discrete tax items could result in significant adjustments to quarterly income tax expense (benefit) in future periods. ​ The Company evaluates its deferred tax assets quarterly to determine if valuation allowances are required. In this evaluation, the Company considers 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 primarily related to depreciation and amortization that would occur within the same jurisdiction and during the carryforward period necessary to absorb the federal and state net operating losses and other deferred tax assets. ​ Deferred tax assets and liabilities are computed by applying the federal, provincial and state income tax rates in effect to the gross amounts of temporary differences and other tax attributes, such as net operating loss carry-forwards. In assessing if the deferred tax assets will be realized, the Company considers whether it is more likely than not that some or all of these deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the period in which these deductible temporary differences reverse. 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 11, “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 restricted 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. Diluted earnings per share is computed by increasing the weighted-average number of outstanding shares of common stock computed in basic earnings per share to include the dilutive effect of Common Stock Equivalents for the period. In periods of net loss, the number of shares used to calculate diluted loss per share is the same as basic net loss per share. ​ The holders of the Company’s Exchangeable Shares (as defined in Note 8, “Stockholders’ Equity”) were entitled to receive dividends or distributions that are 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. ​ Reclassifications ​ Certain amounts in the prior period financial statements have been reclassified to conform to the current year presentation. ​ Recently Adopted Accounting Pronouncements ​ Credit Losses – 2020 with no material impact to its financial statements. See Note 3, “Accounts Receivable,” for additional information with respect to the Company’s allowance for expected credit losses. ​ Fair Value Measurement Disclosures – ​ Recently Issued Accounting Pronouncements ​ Reference Rate Reform ​

Revenue

Revenue	6 Months Ended
	Oct. 31, 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. ​ See Note 14, “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 Judgments ​ 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, net of allowances, were $418.3 million and $393.6 million as of October 31, 2020 and April 30, 2020, respectively. The Company did not have material amounts of contract assets or liabilities as of October 31, 2020 or April 30, 2020. ​

Accounts Receivable

Accounts Receivable	6 Months Ended
	Oct. 31, 2020
Accounts Receivable
Accounts Receivable	3. Accounts Receivable ​ The Company’s trade accounts and notes receivable consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ 2020 2020 ​ ​ (in thousands) Trade receivables ​ $ 423,603 ​ $ 398,739 Other receivables ​ 16,506 ​ 11,656 Allowance for expected credit losses ​ (2,490) ​ (2,861) Other allowances ​ (2,783) ​ ​ (2,280) Trade accounts and notes receivable ​ $ 434,836 ​ $ 405,254 ​ The Company records accounts and notes receivable net of allowances, including the allowance for expected credit losses. The Company maintains an allowance 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 expected credit losses is based on an assessment of individual past due accounts, historical loss information, accounts receivable aging and current economic factors and the Company’s expectation of future economic conditions. Account balances are written off when the potential for recovery is considered remote. ​ The Company routinely assesses the financial strength of its customers and generally does not require collateral. Concentrations of credit risk with respect to trade accounts receivable are limited due to the large number of geographically diverse customers comprising the Company’s customer base. ​ The following table presents the change in the allowance for expected credit losses during the six months ended October 31, 2020: ​ ​ ​ ​ ​ ​ ​ (in thousands) Balance as of April 30, 2020 ​ $ 2,861 Provision ​ ​ (40) Recoveries ​ ​ (250) Write-offs ​ (81) Balance as of October 31, 2020 ​ $ 2,490 ​

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Oct. 31, 2020
Goodwill and Intangible Assets
Goodwill and Intangible Assets	4. Goodwill and Intangible Assets Goodwill The following table presents changes in the carrying amount of goodwill during the six months ended October 31, 2020: ​ ​ ​ ​ ​ ​ Carrying ​ ​ Amount ​ ​ (in thousands) Balance as of April 30, 2020 ​ ​ ​ Goodwill ​ $ 616,147 Accumulated impairment loss ​ ​ (63,074) ​ ​ ​ 553,073 ​ ​ ​ ​ Working capital settlements ​ ​ (159) Translation adjustment ​ 4,572 ​ ​ ​ ​ Balance as of October 31, 2020 ​ ​ ​ Goodwill ​ ​ 620,560 Accumulated impairment loss ​ ​ (63,074) ​ ​ $ 557,486 ​ Intangible Assets The following tables present the components of the Company’s definite-lived intangible assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ Weighted ​ October 31, 2020 ​ ​ Useful ​ Average ​ Gross ​ ​ ​ Net ​ ​ Lives ​ Amortization ​ Carrying ​ Accumulated ​ Carrying ​ (years) Period Amount Amortization Value ​ ​ (dollars in thousands) Customer relationships ​ 5 - 16 ​ 12.8 ​ $ 526,916 ​ $ 298,246 ​ $ 228,670 Definite-lived tradenames ​ 5 - 20 ​ 16.3 ​ 56,907 ​ 12,448 ​ 44,459 Vendor agreements ​ 8 - 10 ​ 8.3 ​ 6,644 ​ 4,970 ​ 1,674 Developed technology ​ 5 ​ 4.9 ​ ​ 5,253 ​ ​ 2,582 ​ ​ 2,671 Other ​ 3 - 5 ​ 3.3 ​ ​ 4,272 ​ ​ 3,195 ​ ​ 1,077 Totals ​ ​ ​ ​ ​ $ 599,992 ​ $ 321,441 ​ $ 278,551 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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 Other ​ 1 - 15 ​ 5.3 ​ ​ 7,836 ​ ​ 4,548 ​ ​ 3,288 Totals ​ ​ ​ ​ ​ $ 592,098 ​ $ 291,581 ​ $ 300,517 ​ 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 flows 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 cannot be reliably determined. Amortization expense related to definite-lived intangible assets was $14.5 million and $16.9 million for the three months ended October 31, 2020 and 2019, respectively, and $28.8 million and $33.8 million for the six months ended October 31, 2020 and 2019, respectively. Amortization expense is recorded in depreciation and amortization expense in the Condensed Consolidated Statements of Operations and Comprehensive Income. The following table summarizes the estimated future amortization expense for definite-lived intangible assets. 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. ​ ​ ​ ​ Year Ending April 30, (in thousands) 2021 (remaining six months) $ 26,862 2022 46,613 2023 38,834 2024 31,731 2025 26,223 Thereafter 108,288 Total $ 278,551 ​ The Company’s indefinite-lived intangible assets consist of tradenames that had a carrying amount of $61.4 million as of October 31, 2020 and April 30, 2020.

Long-Term Debt

Long-Term Debt	6 Months Ended
	Oct. 31, 2020
Long-Term Debt
Long-Term Debt	5. Long-Term Debt The Company’s long-term debt consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ 2020 2020 ​ ​ (in thousands) Term Loan Facility ​ $ 871,919 ​ $ 876,903 Unamortized discount and deferred financing costs on Term Loan Facility ​ ​ (9,540) ​ ​ (10,602) ABL Facility ​ — ​ 80,000 Finance lease obligations ​ 122,058 ​ 128,767 Installment notes at fixed rates up to 5.0%, due in monthly and annual installments through 2024 ​ 12,506 ​ 16,316 Unamortized discount on installment notes ​ ​ (920) ​ ​ (1,098) Canadian Facility ​ — ​ ​ 7,194 Carrying value of debt ​ 996,023 ​ 1,097,480 Less current portion ​ 49,302 ​ 50,201 Long-term debt ​ $ 946,721 ​ $ 1,047,279 ​ Term Loan Facility ​ The Company has a senior secured first lien term loan facility (the “ ” Asset Based Lending Facility The Company has an asset based revolving credit facility (the “ABL Facility”) that provides for aggregate revolving commitments of $445.0 million (including same day swing line borrowings of $44.5 million). 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. At the Company’s option, the interest rates applicable to the loans under the ABL Facility are based on 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. The ABL Facility also contains an unused commitment fee. As of October 31, 2020, the Company had available borrowing capacity of approximately $392.9 million under the ABL Facility. The ABL Facility matures 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. Covenants under the Term Loan Facility and ABL Facility The Term Loan Facility contains a number of covenants that limit our ability and the ability of our 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 restrictive covenants as of October 31, 2020. The ABL Facility contains certain affirmative covenants, including financial and other reporting requirements. The Company was in compliance with all such covenants as of October 31, 2020. Canadian Revolving Credit Facility Through its WSB Titan (“Titan”) subsidiary, the Company has a revolving credit facility (the “Canadian Facility”) that provides for aggregate revolving commitments of $22.5 million ($30.0 million Canadian dollars). The Canadian Facility bears interest at the Canadian prime rate plus a marginal rate based on the level determined by Titan ’ Debt Maturities As of October 31, 2020, the maturities of long-term debt were as follows ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan ​ Finance ​ Installment ​ ​ ​ ​ Facility Leases Notes ​ Total Year ending April 30, ​ (in thousands) 2021 (remaining six months) ​ $ 4,984 ​ $ 17,878 ​ $ 964 ​ $ 23,826 2022 ​ 9,968 ​ ​ 34,324 ​ ​ 4,458 ​ 48,750 2023 ​ 9,968 ​ ​ 29,049 ​ ​ 4,424 ​ 43,441 2024 ​ 9,968 ​ ​ 22,039 ​ ​ 1,800 ​ 33,807 2025 ​ 9,968 ​ ​ 12,110 ​ ​ 860 ​ 22,938 Thereafter ​ 827,063 ​ ​ 6,658 ​ ​ — ​ 833,721 ​ ​ $ 871,919 ​ $ 122,058 ​ $ 12,506 ​ $ 1,006,483 ​

Leases

Leases	6 Months Ended
	Oct. 31, 2020
Leases
Leases	6. 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 one Any 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 Condensed Consolidated Balance Sheets. Finance leases are included in property and equipment, current portion of long-term debt and long-term debt in the Condensed Consolidated Balance Sheets. ​ 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 expensed as incurred. ​ The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 ​ ​ (in thousands) Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 5,960 ​ $ 6,054 ​ $ 12,099 ​ $ 12,113 Interest on lease liabilities ​ ​ 2,863 ​ ​ 3,367 ​ ​ 5,925 ​ ​ 6,789 Operating lease cost ​ ​ 10,630 ​ ​ 10,289 ​ ​ 21,329 ​ ​ 20,709 Variable lease cost ​ ​ 3,157 ​ ​ 3,414 ​ ​ 6,132 ​ ​ 6,613 Total lease cost ​ $ 22,610 ​ $ 23,124 ​ $ 45,485 ​ $ 46,224 ​ 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 Condensed Consolidated Statements of Operations and Comprehensive Income. ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ October 31, ​ ​ 2020 ​ 2019 ​ ​ (in thousands) Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 21,479 ​ $ 20,377 Operating cash flows from finance leases ​ ​ 5,925 ​ ​ 6,789 Financing cash flows from finance leases ​ ​ 14,629 ​ ​ 12,310 Right-of-use assets obtained in exchange for lease obligations ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 17,216 ​ ​ 12,810 Finance leases ​ ​ 12,342 ​ ​ 22,812 ​ Other information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ ​ ​ 2020 2020 ​ ​ ​ (in thousands) ​ Finance leases included in property and equipment ​ ​ ​ ​ ​ ​ ​ Property and equipment ​ $ 170,868 ​ $ 171,380 ​ Accumulated depreciation ​ ​ (47,342) ​ ​ (41,737) ​ Property and equipment, net ​ $ 123,526 ​ $ 129,643 ​ Weighted-average remaining lease term (years) ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 5.0 ​ ​ 4.9 ​ Finance leases ​ ​ 3.5 ​ ​ 3.6 ​ Weighted-average discount rate ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 5.5 % ​ 5.5 % Finance leases ​ ​ 4.9 % ​ 5.0 % ​ Future minimum lease payments under non-cancellable leases as of October 31, 2020 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance Operating Year Ending April 30, ​ (in thousands) 2021 (remaining six months) ​ $ 25,683 ​ $ 19,870 2022 ​ 41,454 ​ 33,301 2023 ​ 32,727 ​ 26,613 2024 ​ 23,445 ​ 21,766 2025 ​ 12,541 ​ 15,068 Thereafter ​ 6,746 ​ 21,474 Total lease payments ​ ​ 142,596 ​ ​ 138,092 Less imputed interest ​ 20,538 ​ 18,276 Total ​ $ 122,058 ​ $ 119,816 ​

Income Taxes

Income Taxes	6 Months Ended
	Oct. 31, 2020
Income Taxes
Income Taxes	7. Income Taxes General. Valuation allowance Uncertain tax positions ​ ​

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Oct. 31, 2020
Stockholders' Equity
Stockholders' Equity	8. Stockholders’ Equity Exchangeable Shares In connection with the acquisition of Titan on June 1, 2018, the Company issued 1.1 million shares of equity that were exchangeable for the Company’s common stock on a one-for-one basis (“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 were 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 allowed the holders to exchange their Exchangeable Shares for GMS common stock at any time on a one-for-one basis. 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 The Company has a common stock repurchase program authorized by its Board of Directors to repurchase up to $75.0 million of 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. These repurchases are 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 share repurchase program does not obligate us to acquire any particular amount of common stock, and it may be suspended or terminated at any time at the Company’s discretion. The Company repurchased approximately 50 thousand shares of its common stock for $1.2 million during the six months ended October 31, 2020. The Company did not repurchase any shares of its common stock during the six months ended October 31, 2019. As of October 31, 2020, the Company had $57.3 million remaining repurchase authorization. Accumulated Other Comprehensive Loss The following table sets forth the changes to accumulated other comprehensive loss, net of tax, by component for the six months ended October 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ Foreign ​ Derivative ​ Other ​ ​ Currency ​ Financial ​ Comprehensive ​ ​ Translation ​ Instruments ​ Loss ​ ​ (in thousands) Balance as of April 30, 2020 ​ $ (40,577) ​ $ (24,505) ​ $ (65,082) Other comprehensive income (loss) before reclassification ​ ​ 19,440 ​ ​ (530) ​ ​ 18,910 Reclassification to earnings from accumulated other comprehensive loss ​ ​ — ​ ​ 4,333 ​ 4,333 Balance as of October 31, 2020 ​ $ (21,137) ​ $ (20,702) ​ $ (41,839) ​ Other comprehensive loss on derivative instruments for the six months ended October 31, 2020 is net of $0.2 million of tax and reclassification to earnings from accumulated other comprehensive loss is net of $1.4 million of tax.

Equity-Based Compensation

Equity-Based Compensation	6 Months Ended
	Oct. 31, 2020
Equity-Based Compensation
Equity-Based Compensation	9. Equity-Based Compensation General The Company measures compensation cost for all share-based awards at fair value on the grant date (or measurement date if different) and recognizes compensation expense, net of estimated forfeitures, over the requisite service period for awards expected to vest. 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 ’ . Equity-based compensation expense related to stock options and restricted stock units was $4.6 million and $3.4 million during the six months ended October 31, 2020 and 2019, respectively, and is included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations and Comprehensive Income. Stock Option Awards The following table presents stock option activity for the six months ended October 31, 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, 2020 1,487 ​ $ 18.85 6.4 ​ $ 3,895 Options granted 321 ​ ​ 23.43 ​ Options exercised (43) ​ 14.55 ​ Options forfeited (48) ​ 25.98 ​ Outstanding as of October 31, 2020 1,717 ​ $ 19.62 6.4 ​ $ 6,958 Exercisable as of October 31, 2020 1,082 ​ $ 17.45 4.8 ​ $ 6,585 Vested and expected to vest as of October 31, 2020 1,709 ​ $ 19.60 6.4 ​ $ 6,957 ​ The aggregate intrinsic value represents the excess of the Company’s closing stock price on the last trading day of the period over 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 six months ended October The fair value of stock options granted during the six months ended October 31, 2020 and 2019 estimated using the Black-Scholes option-pricing model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ October 31, ​ ​ 2020 ​ 2019 Volatility ​ 51.28 % ​ 49.94 % Expected life (years) ​ 6.0 ​ ​ 6.0 ​ Risk-free interest rate ​ 0.30 % ​ 1.97 % Dividend yield ​ — % ​ — % ​ The weighted average grant date fair value of options granted during the $11.13 per share and $10.55 per share, respectively. ​ Restricted Stock Units The following table presents restricted stock unit activity for the six months ended October 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of ​ Average ​ ​ Restricted ​ Grant Date ​ ​ Stock Units ​ Fair Value ​ ​ (shares in thousands) Outstanding as of April 30, 2020 ​ 286 ​ $ 22.71 Granted ​ 212 ​ ​ 23.43 Vested ​ (103) ​ ​ 22.43 Forfeited ​ (28) ​ ​ 23.91 Outstanding as of October 31, 2020 ​ 367 ​ $ 23.12 ​ As of October 31, 2020, there was $6.2 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 2.0 years. Employee Stock Purchase Plan ​ The Company has an employee stock purchase plan (“ESPP”), the terms of which allow for qualified employees 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 purchase period, which is a six-month period ending on December 31 and June 30 of each year. During the six months ended October 31, 2020, 0.1 million shares of the Company’s common stock were purchased under the ESPP at a price of $22.13 per share. The Company recognized $0.3 million and $0.3 million of stock-based compensation expense during the six months ended October 31, 2020 and 2019, respectively, related to the ESPP.

Stock Appreciation Rights, Defe

Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests	6 Months Ended
	Oct. 31, 2020
Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests
Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests	10. 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 six months ended October 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Stock ​ ​ ​ ​ Redeemable ​ ​ Appreciation ​ Deferred ​ Noncontrolling ​ Rights Compensation Interests ​ ​ (in thousands) Balance as of April 30, 2020 ​ $ 24,205 ​ $ 1,660 ​ $ 8,300 Amounts redeemed ​ (181) ​ — ​ — Change in fair value ​ 1,106 ​ 73 ​ 365 Balance as of October 31, 2020 ​ $ 25,130 ​ $ 1,733 ​ $ 8,665 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of April 30, 2020 ​ $ 624 ​ $ — ​ $ — Classified as long-term as of April 30, 2020 ​ ​ 23,581 ​ ​ 1,660 ​ ​ 8,300 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of October 31, 2020 ​ $ 650 ​ $ — ​ $ — Classified as long-term as of October 31, 2020 ​ ​ 24,480 ​ ​ 1,733 ​ ​ 8,665 ​ Total expense related to these instruments was $1.5 million and $2.0 million during the six months ended October 31, 2020 and 2019, respectively, and was included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations and Comprehensive Income. Current and long-term liabilities for stock appreciation rights, deferred compensation and redeemable noncontrolling interests are included in other accrued expenses and liabilities and other liabilities, respectively, in the Condensed Consolidated Balance Sheets. Stock Appreciation Rights Certain subsidiaries have granted stock appreciation rights to certain employees under which payments are dependent on the appreciation in the book value per share, adjusted for certain provisions, of the applicable subsidiary. Settlements of the awards can be made in a combination of cash or installment notes, generally paid over five years, upon a triggering event. As of October 31, 2020, all stock appreciation rights were vested. Liabilities related to these agreements are classified as share-based liability awards and are measured at fair value. Deferred Compensation Subsidiaries’ stockholders have entered into other deferred compensation agreements that granted the stockholders a payment based on a percentage in excess of book value, adjusted for certain provisions, upon an occurrence as defined in the related agreements. These instruments are redeemed in cash or installment notes, generally paid in annual installments over the five years following termination of employment. Liabilities related to these agreements are classified as share-based liability awards and are measured at fair value. Redeemable Noncontrolling Interests Noncontrolling interests were issued to certain employees of certain of the Company’s subsidiaries. All of the noncontrolling interest awards are subject to mandatory redemption on termination of employment for any reason. These instruments are redeemed in cash or installment notes, generally paid in annual installments over the five years following termination of employment. Liabilities related to these agreements are classified as share-based liability awards and are measured at fair value. Under the terms of the employee agreements, the redemption value is determined based on the book value of the subsidiary, as adjusted for certain items. 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.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Oct. 31, 2020
Fair Value Measurements
Fair Value Measurements	11. Fair Value Measurements Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table presents the estimated carrying amount and fair value of the Company’s liabilities measured at fair value on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ ​ 2020 ​ 2020 ​ ​ (in thousands) Interest rate swaps (Level 2) ​ $ 27,180 ​ $ 32,218 Stock appreciation rights (Level 3) ​ ​ 25,130 ​ ​ 24,205 Deferred compensation (Level 3) ​ ​ 1,733 ​ 1,660 Noncontrolling interest holders (Level 3) ​ ​ 8,665 ​ ​ 8,300 ​ Derivative instruments convert the variable interest rate on its Term Loan Facility to a fixed interest rate . The contracts were effective on and terminate on ​ The fair value of derivative instruments is determined using Level 2 inputs. Generally, the Company obtains the Level 2 inputs from its counterparties. Substantially all of the inputs throughout the full term of the instruments can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace. The fair value of the Company’s interest rate swap was determined using widely accepted valuation techniques including a discounted cash flow analysis on the expected cash flows of the derivative. This analysis reflected the contractual terms of the derivatives, including the period to maturity, and used observable market-based inputs, including interest rate curves and implied volatilities. ​ Stock appreciation rights, deferred compensation and redeemable noncontrolling interests 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 subsequent to initial recognition. Such measurements of fair value relate primarily to assets and liabilities measured at fair value in connection with business combinations and long-lived asset impairments. The Company recorded a $1.0 million impairment of operating lease right-of-use assets during the six months ended October 31, 2020. There were no other material long-lived asset impairments during the six months ended October 31, 2020 or 2019.

Transactions With Related Parti

Transactions With Related Parties	6 Months Ended
	Oct. 31, 2020
Transactions With Related Parties
Transactions With Related Parties	12. Transactions With Related Parties The Company purchases inventories from Southern Wall Products, Inc. (“SWP”) on a continuing basis. During the six months ended October 31, 2020 and 2019, certain former executive officers and stockholders and certain directors and stockholders of the Company were stockholders of SWP. As of October 31, 2020, these executive officers and directors were no longer with the Company. The Company purchased inventory from SWP for distribution in the amount of $3.8 million and $3.7 million during the three months ended October 31, 2020 and 2019, respectively, and $7.3 million and $7.3 million during the six months ended October 31, 2020 and 2019, respectively. Amounts due to SWP for purchases of inventory for distribution was $1.2 million as of April 30, 2020 and is included in accounts payable in the Condensed Consolidated Balance Sheets.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Oct. 31, 2020
Commitments and Contingencies
Commitments and Contingencies	13. Commitments and Contingencies ​ 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 “—Insurance Liabilities”, the Company records liabilities for these claims, and assets for amounts recoverable from the insurer, for claims covered by insurance. ​

Segments

Segments	6 Months Ended
	Oct. 31, 2020
Segments
Segments	14. Segments General The Company has eight 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 Chief Operating Decision Maker (“CODM”) in order to assess performance and allocate resources. The Company’s CODM is its Chief Executive Officer. The Company determined it has eight operating segments based on the Company’s eight geographic divisions, which are Central, Midwest, Northeast, Southern, Southeast, Southwest, Western and Canada. During the six months ended October 31, 2020, the Company divided its Southern operating segment into two operating segments, Southern and Southwest, which resulted in an increase (from seven to eight) in the number of operating segments. The Company performed a goodwill impairment test immediately before and after the change in operating segments, which indicated the fair values of the Company’s reporting units exceeded their carrying values. 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. Adjusted EBITDA is not a recognized financial measure under GAAP. However, we believe it assists investors and analysts in comparing our operating performance across reporting periods on a consistent basis by excluding items that we do not believe are indicative of our core operating performance. Management believes Adjusted EBITDA is helpful in highlighting trends in our operating results, while other measures can differ significantly depending on long-term strategic decisions regarding capital structure, the tax jurisdictions in which companies operate and capital investments. 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended October 31, 2020 ​ ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ ​ (in thousands) Geographic divisions ​ $ 805,074 ​ $ 262,534 ​ $ 26,783 ​ $ 82,169 Other ​ ​ 7,782 ​ 2,537 ​ 91 ​ ​ 353 Corporate ​ ​ — ​ — ​ 371 ​ ​ — ​ ​ $ 812,856 ​ $ 265,071 ​ $ 27,245 ​ $ 82,522 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended October 31, 2019 ​ ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ ​ (in thousands) Geographic divisions ​ $ 854,853 ​ $ 281,900 ​ $ 29,024 ​ $ 89,171 Other ​ 7,076 ​ 2,593 ​ 55 ​ ​ 734 Corporate ​ — ​ — ​ 439 ​ ​ — ​ ​ $ 861,929 ​ $ 284,493 ​ $ 29,518 ​ $ 89,905 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended October 31, 2020 ​ ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ ​ (in thousands) Geographic divisions ​ $ 1,599,546 ​ $ 520,372 ​ $ 53,565 ​ $ 164,673 Other ​ 15,883 ​ 5,157 ​ 182 ​ ​ 903 Corporate ​ — ​ — ​ 595 ​ ​ — ​ ​ $ 1,615,429 ​ $ 525,529 ​ $ 54,342 ​ $ 165,576 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended October 31, 2019 ​ ​ ​ ​ ​ Depreciation and ​ Adjusted ​ ​ Net Sales ​ Gross Profit ​ Amortization ​ EBITDA ​ ​ (in thousands) Geographic divisions ​ $ 1,695,010 ​ $ 553,254 ​ $ 57,956 ​ $ 172,254 Other ​ 14,095 ​ 4,893 ​ 108 ​ ​ 1,239 Corporate ​ — ​ — ​ 729 ​ ​ — ​ ​ $ 1,709,105 ​ $ 558,147 ​ $ 58,793 ​ $ 173,493 ​ The following table presents a reconciliation of Adjusted EBITDA to net income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ 2020 2019 ​ 2020 ​ 2019 ​ ​ (in thousands) Net income ​ $ 28,469 ​ $ 29,138 ​ $ 55,688 ​ $ 53,958 Interest expense ​ 13,525 ​ 17,559 ​ 27,606 ​ 35,836 Write-off of debt discount and deferred financing fees ​ ​ ​ ​ ​ 707 ​ ​ — ​ ​ 707 Interest income ​ (14) ​ (6) ​ (51) ​ (18) Provision for income taxes ​ 8,277 ​ 7,927 ​ 17,881 ​ 15,517 Depreciation expense ​ 12,710 ​ 12,592 ​ 25,537 ​ 25,014 Amortization expense ​ 14,535 ​ 16,926 ​ 28,805 ​ 33,779 Stock appreciation expense(a) ​ ​ 314 ​ ​ 1,267 ​ ​ 1,106 ​ ​ 1,327 Redeemable noncontrolling interests(b) ​ 186 ​ (18) ​ 438 ​ 644 Equity-based compensation(c) ​ 3,252 ​ 2,315 ​ 4,857 ​ 3,710 Severance and other permitted costs(d) ​ 762 ​ 1,394 ​ 2,709 ​ 1,948 Transaction costs (acquisitions and other)(e) ​ 25 ​ 327 ​ 125 ​ 1,299 Loss (gain) on disposal and impairment of assets(f) ​ 481 ​ (586) ​ 875 ​ (742) Effects of fair value adjustments to inventory(g) ​ — ​ — ​ — ​ 151 Secondary public offering costs(h) ​ ​ — ​ ​ 363 ​ ​ — ​ ​ 363 Adjusted EBITDA ​ $ 82,522 ​ $ 89,905 ​ $ 165,576 ​ $ 173,493 (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 the calculation of Adjusted EBITDA under the ABL Facility and the Term Loan Facility, including certain unusual, nonrecurring costs due to the COVID-19 pandemic. (e) Represents costs related to acquisitions paid to third parties. (f) Includes impairment of assets resulting from restructuring plans to close certain facilities and gains from the sale of assets. (g) Represents the non-cash cost of sales impact of acquisition accounting adjustments to increase inventory to its estimated fair value. (h) Represents costs paid to third-party advisors related to secondary offerings of our common stock. Revenues by Product The following table presents the Company’s net sales to external customers by main product lines: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ ​ 2020 ​ 2019 ​ 2020 2019 ​ ​ (in thousands) Wallboard $ 330,515 $ 350,618 $ 658,512 ​ $ 692,213 Ceilings ​ 111,293 122,807 224,995 251,917 Steel framing ​ 111,293 136,159 221,780 267,988 Other products ​ 259,755 252,345 510,142 496,987 Total net sales ​ $ 812,856 $ 861,929 $ 1,615,429 $ 1,709,105 ​ Geographic Information ​ The following table presents the Company’s net sales by major geographic area: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ 2020 2019 ​ 2020 2019 ​ ​ (in thousands) United States ​ $ 684,131 $ 744,134 $ 1,363,452 ​ $ 1,475,477 Canada ​ 128,725 117,795 251,977 ​ ​ 233,628 Total net sales ​ $ 812,856 $ 861,929 ​ $ 1,615,429 ​ ​ 1,709,105 ​ The following table presents the Company’s property and equipment, net, by major geographic area: ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ 2020 2020 ​ ​ (in thousands) United States ​ $ 265,941 ​ $ 270,855 Canada ​ 34,203 34,612 Total property and equipment, net ​ $ 300,144 $ 305,467 ​

Earnings Per Common Share

Earnings Per Common Share	6 Months Ended
	Oct. 31, 2020
Earnings Per Common Share
Earnings Per Common Share	15. Earnings Per Common Share The following table sets forth the computation of basic and diluted earnings per share of common stock: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ 2020 ​ 2019 2020 2019 ​ ​ (in thousands, except per share data) Net income ​ $ 28,469 ​ $ 29,138 ​ $ 55,688 ​ $ 53,958 Less: Net income allocated to participating securities ​ ​ — ​ ​ — ​ ​ — ​ ​ 342 Net income attributable to common stockholders ​ $ 28,469 $ 29,138 ​ $ 55,688 ​ $ 53,616 Basic earnings per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 42,723 ​ 41,761 ​ 42,674 ​ 41,382 Basic earnings per common share ​ $ 0.67 ​ $ 0.70 ​ $ 1.30 ​ $ 1.30 Diluted earnings per common share: ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 42,723 ​ 41,761 ​ 42,674 ​ 41,382 Add: Common Stock Equivalents ​ 451 ​ 874 ​ 422 ​ 744 Diluted weighted average common shares outstanding ​ 43,174 ​ 42,635 ​ 43,096 ​ 42,126 Diluted earnings per common share ​ $ 0.66 ​ $ 0.68 ​ $ 1.29 ​ $ 1.27 ​ ​ During the three and six months ended October 31, 2020, approximately 0.5 million and 0.4 million, respectively, Common Stock Equivalents 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.

Business, Basis of Presentati_2

Business, Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Oct. 31, 2020
Business, Basis of Presentation and Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation ​ The condensed consolidated financial statements included in this Quarterly Report on Form 10-Q have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) that permit reduced disclosure for interim periods. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all normal and recurring adjustments necessary for a fair presentation of the results of operations, financial position and cash flows. All adjustments are of a normal recurring nature unless otherwise disclosed. The results of operations for interim periods are not necessarily indicative of results for any other interim period or the entire fiscal year. As a result, the unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements included in our Annual Report on Form 10-K for the fiscal year ended April 30, 2020. ​
Principles of Consolidation	Principles of Consolidation ​ The condensed consolidated financial statements present the results of operations, financial position, stockholders’ equity and cash flows of the Company and its subsidiaries. All material intercompany balances and transactions have been eliminated in consolidation. The results of operations of businesses acquired are included from their respective dates of acquisition. ​
Use of Estimates	Use of Estimates ​ The preparation of financial statements in conformity with 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 as of 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. Gains and losses on foreign currency transactions are recognized in the Condensed Consolidated Statements of Operations and Comprehensive Income within other (expense) income, net. ​
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 October 31, 2020 and April 30, 2020, the aggregate liabilities for medical self-insurance were $4.2 million and $3.8 million, respectively, and are included in other accrued expenses and current liabilities in the Condensed Consolidated Balance Sheets. As of October 31, 2020 and April 30, 2020, reserves for general liability, automobile and workers’ compensation totaled approximately $20.1 million and $19.4 million, respectively, and are included in other accrued expenses and current liabilities and other liabilities in the Condensed Consolidated Balance Sheets. As of October 31, 2020 and April 30, 2020, expected recoveries for medical self-insurance, general liability, automobile and workers’ compensation totaled approximately $8.0 million and $6.0 million, respectively, and are included in prepaid expenses and other current assets and other assets in the Condensed Consolidated Balance Sheets. ​
Income Taxes	Income Taxes ​ The Company considers each interim period an integral part of the annual period and measures tax expense (benefit) using an estimated annual effective income tax rate. Estimates of the annual effective income tax rate at the end of interim periods are, out of necessity, based on evaluation of possible future events and transactions and may be subject to subsequent refinement or revision. The Company forecasts its estimated annual effective income tax rate and then applies that rate to its year-to-date pre-tax ordinary income (loss), subject to certain loss limitation provisions. In addition, certain specific transactions are excluded from the Company’s estimated annual effective tax rate computation, but are discretely recognized within income tax expense (benefit) in their respective interim period. Future changes in the forecasted annual income (loss) projections, tax rate changes, or discrete tax items could result in significant adjustments to quarterly income tax expense (benefit) in future periods. ​ The Company evaluates its deferred tax assets quarterly to determine if valuation allowances are required. In this evaluation, the Company considers 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 primarily related to depreciation and amortization that would occur within the same jurisdiction and during the carryforward period necessary to absorb the federal and state net operating losses and other deferred tax assets. ​ Deferred tax assets and liabilities are computed by applying the federal, provincial and state income tax rates in effect to the gross amounts of temporary differences and other tax attributes, such as net operating loss carry-forwards. In assessing if the deferred tax assets will be realized, the Company considers whether it is more likely than not that some or all of these deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the period in which these deductible temporary differences reverse.
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 11, “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 restricted 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. Diluted earnings per share is computed by increasing the weighted-average number of outstanding shares of common stock computed in basic earnings per share to include the dilutive effect of Common Stock Equivalents for the period. In periods of net loss, the number of shares used to calculate diluted loss per share is the same as basic net loss per share. ​ The holders of the Company’s Exchangeable Shares (as defined in Note 8, “Stockholders’ Equity”) were entitled to receive dividends or distributions that are 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.
Reclassifications	Reclassifications ​ Certain amounts in the prior period financial statements have been reclassified to conform to the current year presentation. ​
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements ​ Credit Losses – 2020 with no material impact to its financial statements. See Note 3, “Accounts Receivable,” for additional information with respect to the Company’s allowance for expected credit losses. ​ Fair Value Measurement Disclosures – ​ Recently Issued Accounting Pronouncements ​ Reference Rate Reform

Accounts Receivable (Tables)

Accounts Receivable (Tables)	6 Months Ended
	Oct. 31, 2020
Accounts Receivable
Schedule of trade accounts and notes receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ 2020 2020 ​ ​ (in thousands) Trade receivables ​ $ 423,603 ​ $ 398,739 Other receivables ​ 16,506 ​ 11,656 Allowance for expected credit losses ​ (2,490) ​ (2,861) Other allowances ​ (2,783) ​ ​ (2,280) Trade accounts and notes receivable ​ $ 434,836 ​ $ 405,254
Schedule of change in allowance for expected credit losses	​ ​ ​ ​ ​ ​ ​ (in thousands) Balance as of April 30, 2020 ​ $ 2,861 Provision ​ ​ (40) Recoveries ​ ​ (250) Write-offs ​ (81) Balance as of October 31, 2020 ​ $ 2,490

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Oct. 31, 2020
Goodwill and Intangible Assets
Schedule of changes in the carrying amount of goodwill	​ ​ ​ ​ ​ ​ Carrying ​ ​ Amount ​ ​ (in thousands) Balance as of April 30, 2020 ​ ​ ​ Goodwill ​ $ 616,147 Accumulated impairment loss ​ ​ (63,074) ​ ​ ​ 553,073 ​ ​ ​ ​ Working capital settlements ​ ​ (159) Translation adjustment ​ 4,572 ​ ​ ​ ​ Balance as of October 31, 2020 ​ ​ ​ Goodwill ​ ​ 620,560 Accumulated impairment loss ​ ​ (63,074) ​ ​ $ 557,486
Schedule of components of definite-lived intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated ​ Weighted ​ October 31, 2020 ​ ​ Useful ​ Average ​ Gross ​ ​ ​ Net ​ ​ Lives ​ Amortization ​ Carrying ​ Accumulated ​ Carrying ​ (years) Period Amount Amortization Value ​ ​ (dollars in thousands) Customer relationships ​ 5 - 16 ​ 12.8 ​ $ 526,916 ​ $ 298,246 ​ $ 228,670 Definite-lived tradenames ​ 5 - 20 ​ 16.3 ​ 56,907 ​ 12,448 ​ 44,459 Vendor agreements ​ 8 - 10 ​ 8.3 ​ 6,644 ​ 4,970 ​ 1,674 Developed technology ​ 5 ​ 4.9 ​ ​ 5,253 ​ ​ 2,582 ​ ​ 2,671 Other ​ 3 - 5 ​ 3.3 ​ ​ 4,272 ​ ​ 3,195 ​ ​ 1,077 Totals ​ ​ ​ ​ ​ $ 599,992 ​ $ 321,441 ​ $ 278,551 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 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 Other ​ 1 - 15 ​ 5.3 ​ ​ 7,836 ​ ​ 4,548 ​ ​ 3,288 Totals ​ ​ ​ ​ ​ $ 592,098 ​ $ 291,581 ​ $ 300,517 ​
Schedule of estimated future aggregate amortization expense	​ ​ ​ ​ Year Ending April 30, (in thousands) 2021 (remaining six months) $ 26,862 2022 46,613 2023 38,834 2024 31,731 2025 26,223 Thereafter 108,288 Total $ 278,551

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Oct. 31, 2020
Long-Term Debt
Schedule of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ 2020 2020 ​ ​ (in thousands) Term Loan Facility ​ $ 871,919 ​ $ 876,903 Unamortized discount and deferred financing costs on Term Loan Facility ​ ​ (9,540) ​ ​ (10,602) ABL Facility ​ — ​ 80,000 Finance lease obligations ​ 122,058 ​ 128,767 Installment notes at fixed rates up to 5.0%, due in monthly and annual installments through 2024 ​ 12,506 ​ 16,316 Unamortized discount on installment notes ​ ​ (920) ​ ​ (1,098) Canadian Facility ​ — ​ ​ 7,194 Carrying value of debt ​ 996,023 ​ 1,097,480 Less current portion ​ 49,302 ​ 50,201 Long-term debt ​ $ 946,721 ​ $ 1,047,279
Scheduled of maturities of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Term Loan ​ Finance ​ Installment ​ ​ ​ ​ Facility Leases Notes ​ Total Year ending April 30, ​ (in thousands) 2021 (remaining six months) ​ $ 4,984 ​ $ 17,878 ​ $ 964 ​ $ 23,826 2022 ​ 9,968 ​ ​ 34,324 ​ ​ 4,458 ​ 48,750 2023 ​ 9,968 ​ ​ 29,049 ​ ​ 4,424 ​ 43,441 2024 ​ 9,968 ​ ​ 22,039 ​ ​ 1,800 ​ 33,807 2025 ​ 9,968 ​ ​ 12,110 ​ ​ 860 ​ 22,938 Thereafter ​ 827,063 ​ ​ 6,658 ​ ​ — ​ 833,721 ​ ​ $ 871,919 ​ $ 122,058 ​ $ 12,506 ​ $ 1,006,483

Leases (Tables)

Leases (Tables)	6 Months Ended
	Oct. 31, 2020
Leases
Summary of components of lease expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ ​ 2020 ​ 2019 ​ 2020 ​ 2019 ​ ​ (in thousands) Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 5,960 ​ $ 6,054 ​ $ 12,099 ​ $ 12,113 Interest on lease liabilities ​ ​ 2,863 ​ ​ 3,367 ​ ​ 5,925 ​ ​ 6,789 Operating lease cost ​ ​ 10,630 ​ ​ 10,289 ​ ​ 21,329 ​ ​ 20,709 Variable lease cost ​ ​ 3,157 ​ ​ 3,414 ​ ​ 6,132 ​ ​ 6,613 Total lease cost ​ $ 22,610 ​ $ 23,124 ​ $ 45,485 ​ $ 46,224
Summary of components of supplemental cash flow information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ October 31, ​ ​ 2020 ​ 2019 ​ ​ (in thousands) Cash paid for amounts included in the measurement of lease liabilities ​ ​ ​ ​ ​ ​ Operating cash flows from operating leases ​ $ 21,479 ​ $ 20,377 Operating cash flows from finance leases ​ ​ 5,925 ​ ​ 6,789 Financing cash flows from finance leases ​ ​ 14,629 ​ ​ 12,310 Right-of-use assets obtained in exchange for lease obligations ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 17,216 ​ ​ 12,810 Finance leases ​ ​ 12,342 ​ ​ 22,812
Summary of other lease information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ ​ ​ 2020 2020 ​ ​ ​ (in thousands) ​ Finance leases included in property and equipment ​ ​ ​ ​ ​ ​ ​ Property and equipment ​ $ 170,868 ​ $ 171,380 ​ Accumulated depreciation ​ ​ (47,342) ​ ​ (41,737) ​ Property and equipment, net ​ $ 123,526 ​ $ 129,643 ​ Weighted-average remaining lease term (years) ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 5.0 ​ ​ 4.9 ​ Finance leases ​ ​ 3.5 ​ ​ 3.6 ​ Weighted-average discount rate ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 5.5 % ​ 5.5 % Finance leases ​ ​ 4.9 % ​ 5.0 %
Schedule of maturities for finance leases	​ ​ ​ ​ ​ ​ ​ ​ ​ Finance Operating Year Ending April 30, ​ (in thousands) 2021 (remaining six months) ​ $ 25,683 ​ $ 19,870 2022 ​ 41,454 ​ 33,301 2023 ​ 32,727 ​ 26,613 2024 ​ 23,445 ​ 21,766 2025 ​ 12,541 ​ 15,068 Thereafter ​ 6,746 ​ 21,474 Total lease payments ​ ​ 142,596 ​ ​ 138,092 Less imputed interest ​ 20,538 ​ 18,276 Total ​ $ 122,058 ​ $ 119,816
Schedule of maturities for operating leases	​ ​ ​ ​ ​ ​ ​ ​ Finance Operating Year Ending April 30, ​ (in thousands) 2021 (remaining six months) ​ $ 25,683 ​ $ 19,870 2022 ​ 41,454 ​ 33,301 2023 ​ 32,727 ​ 26,613 2024 ​ 23,445 ​ 21,766 2025 ​ 12,541 ​ 15,068 Thereafter ​ 6,746 ​ 21,474 Total lease payments ​ ​ 142,596 ​ ​ 138,092 Less imputed interest ​ 20,538 ​ 18,276 Total ​ $ 122,058 ​ $ 119,816

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Oct. 31, 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 ​ Loss ​ ​ (in thousands) Balance as of April 30, 2020 ​ $ (40,577) ​ $ (24,505) ​ $ (65,082) Other comprehensive income (loss) before reclassification ​ ​ 19,440 ​ ​ (530) ​ ​ 18,910 Reclassification to earnings from accumulated other comprehensive loss ​ ​ — ​ ​ 4,333 ​ 4,333 Balance as of October 31, 2020 ​ $ (21,137) ​ $ (20,702) ​ $ (41,839)

Equity-Based Compensation - (Ta

Equity-Based Compensation - (Tables)	6 Months Ended
	Oct. 31, 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, 2020 1,487 ​ $ 18.85 6.4 ​ $ 3,895 Options granted 321 ​ ​ 23.43 ​ Options exercised (43) ​ 14.55 ​ Options forfeited (48) ​ 25.98 ​ Outstanding as of October 31, 2020 1,717 ​ $ 19.62 6.4 ​ $ 6,958 Exercisable as of October 31, 2020 1,082 ​ $ 17.45 4.8 ​ $ 6,585 Vested and expected to vest as of October 31, 2020 1,709 ​ $ 19.60 6.4 ​ $ 6,957
Schedule of weighted average assumptions used in Black-Scholes option-pricing model	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ October 31, ​ ​ 2020 ​ 2019 Volatility ​ 51.28 % ​ 49.94 % Expected life (years) ​ 6.0 ​ ​ 6.0 ​ Risk-free interest rate ​ 0.30 % ​ 1.97 % Dividend yield ​ — % ​ — %
Summary of restricted stock unity activity	​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number of ​ Average ​ ​ Restricted ​ Grant Date ​ ​ Stock Units ​ Fair Value ​ ​ (shares in thousands) Outstanding as of April 30, 2020 ​ 286 ​ $ 22.71 Granted ​ 212 ​ ​ 23.43 Vested ​ (103) ​ ​ 22.43 Forfeited ​ (28) ​ ​ 23.91 Outstanding as of October 31, 2020 ​ 367 ​ $ 23.12

Stock Appreciation Rights, De_2

Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests (Tables)	6 Months Ended
	Oct. 31, 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, 2020 ​ $ 24,205 ​ $ 1,660 ​ $ 8,300 Amounts redeemed ​ (181) ​ — ​ — Change in fair value ​ 1,106 ​ 73 ​ 365 Balance as of October 31, 2020 ​ $ 25,130 ​ $ 1,733 ​ $ 8,665 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of April 30, 2020 ​ $ 624 ​ $ — ​ $ — Classified as long-term as of April 30, 2020 ​ ​ 23,581 ​ ​ 1,660 ​ ​ 8,300 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as current as of October 31, 2020 ​ $ 650 ​ $ — ​ $ — Classified as long-term as of October 31, 2020 ​ ​ 24,480 ​ ​ 1,733 ​ ​ 8,665

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Oct. 31, 2020
Fair Value Measurements
Schedule of liabilities measured at fair value on a recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ ​ 2020 ​ 2020 ​ ​ (in thousands) Interest rate swaps (Level 2) ​ $ 27,180 ​ $ 32,218 Stock appreciation rights (Level 3) ​ ​ 25,130 ​ ​ 24,205 Deferred compensation (Level 3) ​ ​ 1,733 ​ 1,660 Noncontrolling interest holders (Level 3) ​ ​ 8,665 ​ ​ 8,300

Segments (Tables)

Segments (Tables)	6 Months Ended
	Oct. 31, 2020
Segments
Schedule of segment results	​
Reconciliation of Adjusted EBITDA to net income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ 2020 2019 ​ 2020 ​ 2019 ​ ​ (in thousands) Net income ​ $ 28,469 ​ $ 29,138 ​ $ 55,688 ​ $ 53,958 Interest expense ​ 13,525 ​ 17,559 ​ 27,606 ​ 35,836 Write-off of debt discount and deferred financing fees ​ ​ ​ ​ ​ 707 ​ ​ — ​ ​ 707 Interest income ​ (14) ​ (6) ​ (51) ​ (18) Provision for income taxes ​ 8,277 ​ 7,927 ​ 17,881 ​ 15,517 Depreciation expense ​ 12,710 ​ 12,592 ​ 25,537 ​ 25,014 Amortization expense ​ 14,535 ​ 16,926 ​ 28,805 ​ 33,779 Stock appreciation expense(a) ​ ​ 314 ​ ​ 1,267 ​ ​ 1,106 ​ ​ 1,327 Redeemable noncontrolling interests(b) ​ 186 ​ (18) ​ 438 ​ 644 Equity-based compensation(c) ​ 3,252 ​ 2,315 ​ 4,857 ​ 3,710 Severance and other permitted costs(d) ​ 762 ​ 1,394 ​ 2,709 ​ 1,948 Transaction costs (acquisitions and other)(e) ​ 25 ​ 327 ​ 125 ​ 1,299 Loss (gain) on disposal and impairment of assets(f) ​ 481 ​ (586) ​ 875 ​ (742) Effects of fair value adjustments to inventory(g) ​ — ​ — ​ — ​ 151 Secondary public offering costs(h) ​ ​ — ​ ​ 363 ​ ​ — ​ ​ 363 Adjusted EBITDA ​ $ 82,522 ​ $ 89,905 ​ $ 165,576 ​ $ 173,493 (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 the calculation of Adjusted EBITDA under the ABL Facility and the Term Loan Facility, including certain unusual, nonrecurring costs due to the COVID-19 pandemic. (e) Represents costs related to acquisitions paid to third parties. (f) Includes impairment of assets resulting from restructuring plans to close certain facilities and gains from the sale of assets. (g) Represents the non-cash cost of sales impact of acquisition accounting adjustments to increase inventory to its estimated fair value. (h) Represents costs paid to third-party advisors related to secondary offerings of our common stock.
Schedule of net sales to external customers by main product lines	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ ​ 2020 ​ 2019 ​ 2020 2019 ​ ​ (in thousands) Wallboard $ 330,515 $ 350,618 $ 658,512 ​ $ 692,213 Ceilings ​ 111,293 122,807 224,995 251,917 Steel framing ​ 111,293 136,159 221,780 267,988 Other products ​ 259,755 252,345 510,142 496,987 Total net sales ​ $ 812,856 $ 861,929 $ 1,615,429 $ 1,709,105
Schedule of net sales by major geographic area	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ 2020 2019 ​ 2020 2019 ​ ​ (in thousands) United States ​ $ 684,131 $ 744,134 $ 1,363,452 ​ $ 1,475,477 Canada ​ 128,725 117,795 251,977 ​ ​ 233,628 Total net sales ​ $ 812,856 $ 861,929 ​ $ 1,615,429 ​ ​ 1,709,105
Schedule of property and equipment by major geographic area	​ ​ ​ ​ ​ ​ ​ ​ ​ October 31, ​ April 30, ​ 2020 2020 ​ ​ (in thousands) United States ​ $ 265,941 ​ $ 270,855 Canada ​ 34,203 34,612 Total property and equipment, net ​ $ 300,144 $ 305,467

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	6 Months Ended
	Oct. 31, 2020
Earnings Per Common Share
Schedule of computation of basic and diluted earnings per share of common stock	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ October 31, ​ October 31, ​ 2020 ​ 2019 2020 2019 ​ ​ (in thousands, except per share data) Net income ​ $ 28,469 ​ $ 29,138 ​ $ 55,688 ​ $ 53,958 Less: Net income allocated to participating securities ​ ​ — ​ ​ — ​ ​ — ​ ​ 342 Net income attributable to common stockholders ​ $ 28,469 $ 29,138 ​ $ 55,688 ​ $ 53,616 Basic earnings per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 42,723 ​ 41,761 ​ 42,674 ​ 41,382 Basic earnings per common share ​ $ 0.67 ​ $ 0.70 ​ $ 1.30 ​ $ 1.30 Diluted earnings per common share: ​ ​ ​ ​ Basic weighted average common shares outstanding ​ 42,723 ​ 41,761 ​ 42,674 ​ 41,382 Add: Common Stock Equivalents ​ 451 ​ 874 ​ 422 ​ 744 Diluted weighted average common shares outstanding ​ 43,174 ​ 42,635 ​ 43,096 ​ 42,126 Diluted earnings per common share ​ $ 0.66 ​ $ 0.68 ​ $ 1.29 ​ $ 1.27

Business, Basis of Presentati_3

Business, Basis of Presentation and Summary of Significant Accounting Policies - Business (Details)	6 Months Ended
	Oct. 31, 2020item
Business
Number of distribution centers	260

Business, Basis of Presentati_4

Business, Basis of Presentation and Summary of Significant Accounting Policies - Insurance Liabilities (Details) - USD ($) $ in Millions	Oct. 31, 2020	Apr. 30, 2020
Other accrued expenses and current liabilities.
Insurance Liabilities
Aggregate liabilities for medical self-insurance	$ 4.2	$ 3.8
General liability
Insurance Liabilities
Deductible amount	0.3
Primary layer of insurance coverage	0.3
Workers' compensation
Insurance Liabilities
Deductible amount	0.5
Primary layer of insurance coverage	0.5
Automobile
Insurance Liabilities
Deductible amount	1
Primary layer of insurance coverage	1
General liability, workers' compensation and automobile | Other accrued expenses and current liabilities.
Insurance Liabilities
Reserve for insurance	20.1	19.4
General liability, workers' compensation and automobile | Prepaid expenses and other current assets
Insurance Liabilities
Insurance recovery receivable	8	$ 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

Revenue (Details)

Revenue (Details) - USD ($) $ in Millions	6 Months Ended
	Oct. 31, 2020	Apr. 30, 2020
Revenue
Revenue, Practical Expedient, Financing Component [true false]	true
Revenue, Practical Expedient, Remaining Performance Obligation [true/false]	true
Receivables from contracts with customers	$ 418.3	$ 393.6

Accounts Receivable - Trade Acc

Accounts Receivable - Trade Accounts And Notes Receivable (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Accounts Receivable
Trade receivables	$ 423,603	$ 398,739
Other receivables	16,506	11,656
Allowance for expected credit losses	(2,490)	(2,861)
Other allowances	(2,783)	(2,280)
Trade accounts and notes receivable	$ 434,836	$ 405,254

Accounts Receivable - Change In

Accounts Receivable - Change In Allowance (Details) $ in Thousands	6 Months Ended
	Oct. 31, 2020USD ($)
Change in allowance
Beginning balance	$ 2,861
Ending balance	2,490
Accounts receivable.
Change in allowance
Beginning balance	2,861
Provision	(40)
Recoveries	(250)
Write-offs	(81)
Ending balance	$ 2,490

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill (Details) $ in Thousands	6 Months Ended
	Oct. 31, 2020USD ($)
Carrying Amount of Goodwill
Goodwill	$ 616,147
Accumulated impairment loss	(63,074)
Balance	553,073
Working capital settlement	(159)
Translation adjustment	4,572
Goodwill	620,560
Accumulated impairment loss	(63,074)
Balance	$ 557,486

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Definite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Oct. 31, 2020	Apr. 30, 2020
Definite-lived intangible assets
Gross Carrying Amount	$ 599,992	$ 592,098
Accumulated Amortization	321,441	291,581
Total	$ 278,551	$ 300,517
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	$ 526,916	$ 516,928
Accumulated Amortization	298,246	270,029
Total	$ 228,670	$ 246,899
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	$ 56,907	$ 55,654
Accumulated Amortization	12,448	10,474
Total	$ 44,459	$ 45,180
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	4,970	4,567
Total	$ 1,674	$ 2,077
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	$ 5,253	$ 5,036
Accumulated Amortization	2,582	1,963
Total	$ 2,671	$ 3,073
Other intangible assets
Definite-lived intangible assets
Weighted Average Amortization Period (in years)	3 years 3 months 18 days	5 years 3 months 18 days
Gross Carrying Amount	$ 4,272	$ 7,836
Accumulated Amortization	3,195	4,548
Total	$ 1,077	$ 3,288
Other intangible assets | Minimum
Definite-lived intangible assets
Estimated Useful Lives (years)	3 years	1 year
Other intangible assets | Maximum
Definite-lived intangible assets
Estimated Useful Lives (years)	5 years	15 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Amortization (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Intangible assets
Amortization expense	$ 14,535	$ 16,926	$ 28,805	$ 33,779
Depreciation and amortization expense
Intangible assets
Amortization expense	$ 14,500	$ 16,900	$ 28,800	$ 33,800

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Estimated Aggregate Amortization Expense (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Estimated aggregate future amortization expense
2021 (remaining six months)	$ 26,862
2022	46,613
2023	38,834
2024	31,731
2025	26,223
Thereafter	108,288
Total	$ 278,551	$ 300,517

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets - Indefinite-Lived Intangible Assets (Details) - USD ($) $ in Millions	Oct. 31, 2020	Apr. 30, 2020
Goodwill and Intangible Assets
Tradenames	$ 61.4	$ 61.4

Long-Term Debt - Components (De

Long-Term Debt - Components (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Long-term debt
Carrying value of debt	$ 996,023	$ 1,097,480
Less current portion	49,302	50,201
Long-term debt	946,721	1,047,279
Term Loan Facility
Long-term debt
Carrying value of debt	871,919	876,903
Unamortized discount and deferred financing costs	(9,540)	(10,602)
ABL Facility
Long-term debt
Carrying value of debt		80,000
Finance lease obligations
Long-term debt
Carrying value of debt	122,058	128,767
Installment notes
Long-term debt
Carrying value of debt	$ 12,506	$ 16,316
Interest rate	5.00%	5.00%
Unamortized discount	$ (920)	$ (1,098)
Canadian Facility
Long-term debt
Carrying value of debt		$ 7,194

Long-Term Debt - Acquisition De

Long-Term Debt - Acquisition Debt (Details) - Term Loan Facility $ in Millions	6 Months Ended
	Oct. 31, 2020USD ($)
Long-term debt
Aggregate principal amount	$ 871.9
Borrowing interest rate (as a percent)	2.90%
Loan quarterly payments	$ 2.5
Loan quarterly payments of the principal amount (as a percent)	0.25%
LIBOR
Long-term debt
Margin added to variable rate (as a percent)	2.75%
Variable rate floor (as a percent)	0.00%

Long-Term Debt - Asset-Based Le

Long-Term Debt - Asset-Based Lending Facility (Details) - ABL Facility $ in Millions	Oct. 31, 2020USD ($)
Long-term debt
Maximum amount under the facility	$ 445
Available borrowings under the facility	392.9
Swing-line
Long-term debt
Maximum amount under the facility	$ 44.5

Long-Term Debt - Canadian Revol

Long-Term Debt - Canadian Revolving Credit Facility (Details) - Canadian Facility $ in Millions, $ in Millions	Oct. 31, 2020USD ($)	Jun. 01, 2018USD ($)	Jun. 01, 2018CAD ($)
Debt Instrument [Line Items]
Maximum amount under the facility		$ 22.5	$ 30
Available borrowings under the facility	$ 22.5

Long-Term Debt - Maturities (De

Long-Term Debt - Maturities (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Debt maturities
2021 (remaining six months)	$ 23,826
2022	48,750
2023	43,441
2024	33,807
2025	22,938
Thereafter	833,721
Total	1,006,483
Term Loan Facility
Debt maturities
2021 (remaining six months)	4,984
2022	9,968
2023	9,968
2024	9,968
2025	9,968
Thereafter	827,063
Total	871,919
Finance lease obligations
Debt maturities
2021 (remaining six months)	17,878
2022	34,324
2023	29,049
2024	22,039
2025	12,110
Thereafter	6,658
Total	122,058
Installment notes
Debt maturities
2021 (remaining six months)	964
2022	4,458
2023	4,424
2024	1,800
2025	860
Total	12,506
Long Term Debt
Unamortized discount	$ 920	$ 1,098

Leases (Details)

Leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Leases
Option to extend			true
Finance lease cost:
Amortization of right-of-use assets	$ 5,960	$ 6,054	$ 12,099	$ 12,113
Interest on lease liabilities	2,863	3,367	5,925	6,789
Operating lease cost	10,630	10,289	21,329	20,709
Variable lease cost	3,157	3,414	6,132	6,613
Total lease cost	$ 22,610	$ 23,124	$ 45,485	$ 46,224
Minimum
Leases
Lease term (in years)	1 year		1 year
Renewal lease term (in years)	1 year		1 year
Maximum
Leases
Lease term (in years)	11 years		11 years
Renewal lease term (in years)	5 years		5 years

Leases - Supplemental cash flow

Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 21,479	$ 20,377
Operating cash flows from finance leases	5,925	6,789
Financing cash flows from finance leases	14,629	12,310
Right-of-use assets obtained in exchange for lease obligations - Operating leases	17,216	12,810
Right-of-use assets obtained in exchange for lease obligations - Finance leases	$ 12,342	$ 22,812

Leases - Other information (Det

Leases - Other information (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Finance leases included in property and equipment
Accumulated depreciation	$ (174,832)	$ (158,554)
Property and equipment, net	$ 300,144	$ 305,467
Weighted-average remaining lease term (years) - Operating leases	5 years	4 years 10 months 24 days
Weighted-average remaining lease term (years) - Finance leases	3 years 6 months	3 years 7 months 6 days
Weighted-average discount rate - Operating leases	5.50%	5.50%
Weighted-average discount rate - Finance leases	4.90%	5.00%
Finance Leased Assets
Finance leases included in property and equipment
Property and equipment	$ 170,868	$ 171,380
Accumulated depreciation	(47,342)	(41,737)
Property and equipment, net	$ 123,526	$ 129,643

Leases - Future minimum lease p

Leases - Future minimum lease payments under non-cancellable leases (Details) $ in Thousands	Oct. 31, 2020USD ($)
Finance lease
2021 (remaining six months)	$ 25,683
2022	41,454
2023	32,727
2024	23,445
2025	12,541
Thereafter	6,746
Total lease payments	142,596
Less imputed interest	20,538
Total	122,058
Operating lease
2021 (remaining six months)	19,870
2022	33,301
2023	26,613
2024	21,766
2025	15,068
Thereafter	21,474
Total lease payments	138,092
Less imputed interest	18,276
Total	$ 119,816

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Apr. 30, 2020
Effective income tax rate (as a percent)	24.30%	22.30%
Valuation allowance	$ 10.6		$ 10.2
Reserve for uncertain tax positions	$ 0		$ 0
Domestic
Federal statutory rate (as a percent)	21.00%

Stockholders' Equity - Exchange

Stockholders' Equity - Exchangeable Shares, Share Repurchase Program and Secondary Public Offering (Details) shares in Thousands, $ in Millions	Jun. 13, 2019shares	Jun. 01, 2018shares	Oct. 31, 2020USD ($)shares	Nov. 30, 2018USD ($)
Exchangeable Shares and Share Repurchase Program
Number of shares repurchased | shares			50
Shares repurchased, cost | $			$ 1.2
Remaining amount under repurchase program | $			$ 57.3
Maximum
Exchangeable Shares and Share Repurchase Program
Stock repurchase program, authorized amount | $				$ 75
Titan
Exchangeable Shares and Share Repurchase Program
Issuance of shares to current shareholders of Titan (in shares) | shares		1,100
Exchangeable shares converted | shares	1,100
Exchangeable shares conversion ratio		1

Stockholders' Equity - Accumula

Stockholders' Equity - Accumulated Other Comprehensive Loss (Details) $ in Thousands	6 Months Ended
	Oct. 31, 2020USD ($)
Accumulated other comprehensive (loss) income
Balance	$ 633,981
Balance	717,897
Other comprehensive loss on derivative instruments before reclassification, tax	200
Reclassification of (decrease) increase in fair value financial instruments from Accumulated other comprehensive income (loss)
Amount expected to be reclassified to earnings during next twelve months	(1,400)
Accumulated Other Comprehensive Loss
Accumulated other comprehensive (loss) income
Balance	(65,082)
Other comprehensive income before reclassification	18,910
Reclassification to earnings from accumulated other comprehensive loss	4,333
Balance	(41,839)
Foreign Currency Translation
Accumulated other comprehensive (loss) income
Balance	(40,577)
Other comprehensive income before reclassification	19,440
Balance	(21,137)
Derivative Financial Instruments
Accumulated other comprehensive (loss) income
Balance	(24,505)
Other comprehensive income before reclassification	(530)
Reclassification to earnings from accumulated other comprehensive loss	4,333
Balance	$ (20,702)

Equity-Based Compensation - Sto

Equity-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Apr. 30, 2020
Other disclosures
Equity-based compensation	$ 3,252	$ 2,315	$ 4,857	$ 3,710
Selling, general and administrative expenses
Other disclosures
Equity-based compensation			$ 4,600	3,400
Stock Options
Number of Options
Outstanding, beginning of the period (in shares)			1,487
Options granted (in shares)			321
Options exercised (in shares)			(43)
Options forfeited (in shares)			(48)
Outstanding, end of the period (in shares)	1,717		1,717		1,487
Exercisable at end of period (in shares)	1,082		1,082
Vested and expected to vest at end of period (in shares)	1,709		1,709
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)			$ 18.85
Options granted (in dollars per share)			23.43
Options exercised (in dollars per share)			14.55
Options forfeited (in dollars per share)			25.98
Outstanding, end of the period (in dollars per share)	$ 19.62		19.62		$ 18.85
Exercisable at end of period (in dollars per share)	17.45		17.45
Vested and expected to vest at end of period (in dollars per share)	$ 19.60		$ 19.60
Other disclosures
Weighted Average Remaining Contractual Life, Outstanding (in years)			6 years 4 months 24 days		6 years 4 months 24 days
Weighted Average Remaining Contractual Life, Exercisable at end of period (in years)			4 years 9 months 18 days
Weighted Average Remaining Contractual Life, Vested and expected to vest at end of period (in years)			6 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding	$ 6,958		$ 6,958		$ 3,895
Aggregate Intrinsic Value, Exercisable at end of period	6,585		6,585
Aggregate Intrinsic Value, Vested and expected to vest at end of period	6,957		6,957
Intrinsic value of options exercised			300	$ 8,600
Unrecognized compensation cost	$ 5,400		$ 5,400
Weighted-average period for recognition of unrecognized compensation expense (in years)			2 years 2 months 12 days
Options granted (in shares)			321

Equity-Based Compensation - Bla

Equity-Based Compensation - Black Scholes Options - Pricing Model (Details) - Stock Options - $ / shares	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Stock options
Volatility (as a percent)	51.28%	49.94%
Expected life (years)	6 years	6 years
Risk-free interest rate (as a percent)	0.30%	1.97%
Dividend yield (as a percent)	0.00%	0.00%
Weighted average grant date fair value (in dollars per share)	$ 11.13	$ 10.55

Equity-Based Compensation - Res

Equity-Based Compensation - Restricted Stock Units (Details) - Restricted stock units $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended
	Oct. 31, 2020USD ($)$ / sharesshares
Number of Restricted Stock Units
Outstanding, beginning of the period (in shares) | shares	286
Granted (in shares) | shares	212
Vested (in shares) | shares	(103)
Forfeited (in shares) | shares	(28)
Outstanding, end of the period (in shares) | shares	367
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 22.71
Granted (in dollars per share) | $ / shares	23.43
Vested (in dollars per share) | $ / shares	22.43
Forfeited (in dollars per share) | $ / shares	23.91
Outstanding, end of the period (in dollars per share) | $ / shares	$ 23.12
Unrecognized compensation cost | $	$ 6.2
Weighted-average period for recognition of unrecognized compensation expense (in years)	2 years

Equity-Based Compensation - Emp

Equity-Based Compensation - Employee Stock Purchase Plan (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 3,252	$ 2,315	$ 4,857	$ 3,710
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 purchased under ESPP			0.1
Average price per share	$ 22.13		$ 22.13
Share-based compensation expense			$ 300	$ 300

Stock Appreciation Rights, De_3

Stock Appreciation Rights, Deferred Compensation and Redeemable Noncontrolling Interests (Details) - USD ($) $ in Thousands	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Apr. 30, 2020
Selling, general and administrative expenses
Equity based compensation arrangements
Expense related to equity based compensation arrangements	$ 1,500	$ 2,000
Stock Appreciation Rights
Equity based compensation arrangements
Award liability as of beginning of period	24,205
Amounts redeemed	(181)
Change in fair value	1,106
Award liability as of end of period	25,130
Current liabilities related to plans	650		$ 624
Long-term liabilities related to plans	$ 24,480		23,581
Settlement period	5 years
Deferred Compensation
Equity based compensation arrangements
Award liability as of beginning of period	$ 1,660
Change in fair value	73
Award liability as of end of period	1,733
Long-term liabilities related to plans	$ 1,733		1,660
Settlement period	5 years
Redeemable Noncontrolling Interests
Equity based compensation arrangements
Award liability as of beginning of period	$ 8,300
Change in fair value	365
Award liability as of end of period	8,665
Long-term liabilities related to plans	$ 8,665		$ 8,300
Settlement period	5 years

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2020	Apr. 30, 2020	Feb. 28, 2019
Fair Value Measurements
Impairment charges		$ 1,000
Fair Value, Measurements, Recurring | Level 3
Fair Value Measurements
Stock appreciation rights	$ 25,130	25,130	$ 24,205
Deferred compensation	1,733	1,733	1,660
Noncontrolling interest holders	8,665	8,665	8,300
Interest rate swap agreements
Fair Value Measurements
Interest rate swap gains (losses)	(2,200)	(4,300)
Expected amount of pre-tax net losses will be reclassified from accumulated other comprehensive income (loss) into earnings during the next twelve months		11,700
Interest rate swap agreements | Fair Value, Measurements, Recurring | Level 2
Fair Value Measurements
Derivative liabilities	27,180	27,180	$ 32,218
Interest rate swap agreements | Term Loan Facility
Fair Value Measurements
Notional amount				$ 500,000
Interest rate swap agreements | LIBOR | Term Loan Facility
Fair Value Measurements
Fixed interest rate				2.46%
Other accrued expenses and current liabilities | Interest rate swap agreements
Fair Value Measurements
Derivative liabilities	11,700	11,700
Other liabilities | Interest rate swap agreements
Fair Value Measurements
Derivative liabilities	$ 15,500	$ 15,500

Transactions With Related Par_2

Transactions With Related Parties - Purchased Inventories (Details) - Southern Wall Products, Inc. - Inventory purchases - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Apr. 30, 2020
Transactions with related parties
Purchases from related party	$ 3.8	$ 3.7	$ 7.3	$ 7.3
Accounts payable
Transactions with related parties
Due to SWP					$ 1.2

Segments (Details)

Segments (Details)	Apr. 30, 2020segment	Oct. 31, 2020segmentdivision
Segments
Number of operating segments | segment	7	8
Number of reportable segments | segment		1
Number of geographic divisions | division		8
Number of operating segment, divisions | division		2

Segments - Net Sales, Adjusted

Segments - Net Sales, Adjusted EBITDA and Certain Other Measures (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Apr. 30, 2020
Segment information
Net sales	$ 812,856	$ 861,929	$ 1,615,429	$ 1,709,105
Gross Profit	265,071	284,493	525,529	558,147
Depreciation and Amortization	27,245	29,518	54,342	58,793
Adjusted EBITDA	82,522	89,905	165,576	173,493
Total assets	2,210,874		2,210,874		$ 2,288,782
Geographic divisions
Segment information
Net sales	805,074	854,853	1,599,546	1,695,010
Gross Profit	262,534	281,900	520,372	553,254
Depreciation and Amortization	26,783	29,024	53,565	57,956
Adjusted EBITDA	82,169	89,171	164,673	172,254
Other.
Segment information
Net sales	7,782	7,076	15,883	14,095
Gross Profit	2,537	2,593	5,157	4,893
Depreciation and Amortization	91	55	182	108
Adjusted EBITDA	353	734	903	1,239
Corporate
Segment information
Depreciation and Amortization	$ 371	$ 439	$ 595	$ 729

Segments - Reconciliation of Ne

Segments - Reconciliation of Net Income to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Segments
Net income	$ 28,469	$ 27,219	$ 29,138	$ 24,820	$ 55,688	$ 53,958
Interest expense	13,525		17,559		27,606	35,836
Write-off of debt discount and deferred financing fees			707			707
Interest income	(14)		(6)		(51)	(18)
Provision for income taxes	8,277		7,927		17,881	15,517
Depreciation expense	12,710		12,592		25,537	25,014
Amortization expense	14,535		16,926		28,805	33,779
Stock appreciation expense	314		1,267		1,106	1,327
Redeemable noncontrolling interests	186		(18)		438	644
Equity-based compensation	3,252		2,315		4,857	3,710
Severance and other permitted costs	762		1,394		2,709	1,948
Transaction costs (acquisitions and other)	25		327		125	1,299
Loss (gain) on disposal and impairment of assets	481		(586)		875	(742)
Effects of fair value adjustments to inventory						151
Secondary public offering costs			363			363
Adjusted EBITDA	$ 82,522		$ 89,905		$ 165,576	$ 173,493

Segments - Net Sales by Main Pr

Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Revenue from external customers
Total net sales	$ 812,856	$ 861,929	$ 1,615,429	$ 1,709,105
Wallboard
Revenue from external customers
Total net sales	330,515	350,618	658,512	692,213
Ceilings
Revenue from external customers
Total net sales	111,293	122,807	224,995	251,917
Steel framing
Revenue from external customers
Total net sales	111,293	136,159	221,780	267,988
Other products
Revenue from external customers
Total net sales	$ 259,755	$ 252,345	$ 510,142	$ 496,987

Segments - Net sales by major g

Segments - Net sales by major geographic area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$ 812,856	$ 861,929	$ 1,615,429	$ 1,709,105
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	684,131	744,134	1,363,452	1,475,477
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$ 128,725	$ 117,795	$ 251,977	$ 233,628

Segments - Property and equipme

Segments - Property and equipment, net, by major geographic area (Details) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 300,144	$ 305,467
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	265,941	270,855
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 34,203	$ 34,612

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended				6 Months Ended
		Oct. 31, 2020	Jul. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
Computation of basic and diluted earnings per share of common stock
Net income		$ 28,469	$ 27,219	$ 29,138	$ 24,820	$ 55,688	$ 53,958
Less: Net income allocated to participating securities							342
Net income attributable to common stockholders		$ 28,469		$ 29,138		$ 55,688	$ 53,616
Basic earnings per common share:
Basic weighted average common shares outstanding (in shares)		42,723		41,761		42,674	41,382
Basic earnings per common share (in dollars per share)	[1]	$ 0.67		$ 0.70		$ 1.30	$ 1.30
Diluted earnings per common share:
Basic weighted average common shares outstanding (in shares)		42,723		41,761		42,674	41,382
Add: Common Stock Equivalents		451		874		422	744
Diluted weighted average common shares outstanding (in shares)		43,174		42,635		43,096	42,126
Diluted earnings per common share (in dollars per share)	[1]	$ 0.66		$ 0.68		$ 1.29	$ 1.27
Shares were not included in the calculation of Diluted loss per common share
Anti-dilutive shares		500				400
[1]	See Note 15 for detailed calculations .