Advanced Drainage Systems (WMS) 10-Q 4 Nov 21 2021 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-36557
Entity Registrant Name	ADVANCED DRAINAGE SYSTEMS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	51-0105665
Entity Address, Address Line One	4640 Trueman Boulevard
Entity Address, City or Town	Hilliard
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	43026
City Area Code	614
Local Phone Number	658-0050
Title of each class	Common Stock, $0.01 par value per share
Trading Symbol(s)	WMS
Name of each exchange on which registered	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		71,241,663
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001604028
Current Fiscal Year End Date	--03-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Current assets:
Cash	$ 14,005	$ 195,009
Receivables (less allowance for doubtful accounts of $8,068 and $5,323, respectively)	361,466	236,191
Inventories	425,244	300,961
Other current assets	16,858	10,817
Total current assets	817,573	742,978
Property, plant and equipment, net	544,187	504,275
Other assets:
Goodwill	598,976	599,072
Intangible assets, net	450,925	482,016
Other assets	94,963	85,491
Total assets	2,506,624	2,413,832
Current liabilities:
Current maturities of debt obligations	7,000	7,000
Current maturities of finance lease obligations	17,467	19,318
Accounts payable	257,576	171,098
Other accrued liabilities	129,818	116,151
Accrued income taxes	1,978	4,703
Total current liabilities	413,839	318,270
Long-term debt obligations (less unamortized debt issuance costs of $1,839 and $2,030, respectively)	901,511	782,220
Long-term finance lease obligations	35,149	32,964
Deferred tax liabilities	163,238	162,185
Other liabilities	61,366	54,767
Total liabilities	1,575,103	1,350,406
Commitments and contingencies (see Note 9)
Mezzanine equity:
Redeemable convertible preferred stock: $0.01 par value; 47,070 shares authorized; 44,170 shares issued; 18,282 and 19,275 shares outstanding, respectively	228,532	240,944
Deferred compensation – unearned ESOP shares	(7,014)	(11,033)
Total mezzanine equity	221,518	229,911
Stockholders’ equity:
Common stock; $0.01 par value: 1,000,000 shares authorized; 73,333 and 72,071 shares issued, respectively; 70,137 and 71,570 shares outstanding, respectively	11,590	11,578
Paid-in capital	968,198	918,587
Common stock in treasury, at cost	(315,935)	(10,959)
Accumulated other comprehensive loss	(26,020)	(24,220)
Retained earnings (deficit)	57,386	(75,202)
Total ADS stockholders’ equity	695,219	819,784
Noncontrolling interest in subsidiaries	14,784	13,731
Total stockholders’ equity	710,003	833,515
Total liabilities, mezzanine equity and stockholders’ equity	$ 2,506,624	$ 2,413,832

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Allowance for doubtful accounts	$ 8,068	$ 5,323
Unamortized debt issuance costs	$ 1,839	$ 2,030
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	73,333,000	72,071,000
Common stock, shares outstanding	70,137,000	71,570,000
Redeemable Convertible Preferred Stock
Mezzanine equity, par value	$ 0.01	$ 0.01
Mezzanine equity, shares authorized	47,070,000	47,070,000
Mezzanine equity, shares issued	44,170,000	44,170,000
Mezzanine equity, shares outstanding	18,282,000	19,275,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Net sales	$ 706,471	$ 544,187	$ 1,375,771	$ 1,052,826
Cost of goods sold	506,414	338,330	974,593	658,466
Gross profit	200,057	205,857	401,178	394,360
Operating expenses:
Selling, general and administrative	73,951	65,701	150,172	127,477
(Gain) loss on disposal of assets and costs from exit and disposal activities	(901)	627	(912)	2,274
Intangible amortization	15,446	17,955	31,091	35,937
Income from operations	111,561	121,574	220,827	228,672
Other expense:
Interest expense	8,437	9,360	16,344	19,330
Derivative (gains) loss and other (income) expense, net	202	(151)	(1,812)	(718)
Income before income taxes	102,922	112,365	206,295	210,060
Income tax expense	26,816	31,827	53,271	59,027
Equity in net income of unconsolidated affiliates	(206)	(67)	(411)	(240)
Net income	76,312	80,605	153,435	151,273
Less: net income attributable to noncontrolling interest	953	369	2,089	571
Net income attributable to ADS	$ 75,359	$ 80,236	$ 151,346	$ 150,702
Weighted average common shares outstanding:
Basic (in shares)	70,464	69,843	70,993	69,612
Diluted (in shares)	71,924	70,755	72,614	70,459
Net income per share:
Basic (in dollars per share)	$ 0.90	$ 0.95	$ 1.78	$ 1.78
Diluted (in dollars per share)	$ 0.88	$ 0.93	$ 1.74	$ 1.76

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 76,312	$ 80,605	$ 153,435	$ 151,273
Currency translation (loss) gain	(3,406)	2,406	(1,365)	5,556
Comprehensive income	72,906	83,011	152,070	156,829
Less: other comprehensive (loss) income attributable to noncontrolling interest	(180)	338	435	657
Less: net income attributable to noncontrolling interest	953	369	2,089	571
Total comprehensive income attributable to ADS	$ 72,133	$ 82,304	$ 149,546	$ 155,601

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities
Net income	$ 153,435	$ 151,273
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	68,850	71,559
Deferred income taxes	15	(3,446)
(Gain) loss on disposal of assets and costs from exit and disposal activities	(912)	2,274
ESOP and stock-based compensation	38,437	27,088
Amortization of deferred financing charges	191	197
Fair market value adjustments to derivatives	(446)	(1,455)
Equity in net income of unconsolidated affiliates	(411)	(240)
Other operating activities	441	(236)
Changes in working capital:
Receivables	(138,063)	(60,106)
Inventories	(124,429)	60,663
Prepaid expenses and other current assets	(6,738)	(3,666)
Accounts payable, accrued expenses, and other liabilities	104,508	42,263
Net cash provided by operating activities	94,878	286,168
Cash Flows from Investing Activities
Capital expenditures	(63,764)	(28,959)
Other investing activities	1,556	455
Net cash used in investing activities	(62,208)	(28,504)
Cash Flows from Financing Activities
Payments on syndicated Term Loan Facility	(3,500)	(103,500)
Proceeds from Revolving Credit Agreement	146,800	0
Payments on Revolving Credit Agreement	(24,200)	(100,000)
Payments on finance lease obligations	(10,437)	(10,677)
Repurchase of common stock	(292,000)	0
Cash dividends paid	18,758	15,402
Dividends paid to noncontrolling interest holder	(1,471)	0
Proceeds from exercise of stock options	3,179	3,275
Payment of withholding taxes on vesting of restricted stock units	(12,976)	0
Other financing activities	(230)	(1,489)
Net cash used in financing activities	(213,593)	(227,793)
Effect of exchange rate changes on cash	(81)	(221)
Net change in cash	(181,004)	29,650
Cash at beginning of period	195,009	174,233
Cash at end of period	14,005	203,883
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	61,813	39,213
Cash paid for interest	15,383	20,923
Non-cash operating, investing and financing activities:
Acquisition of property, plant and equipment under finance lease and incurred lease obligations	11,403	2,719
Balance in accounts payable for the acquisition of property, plant and equipment	$ 11,499	$ 4,100

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Total ADS Stockholders' Equity	Total ADS Stockholders' EquityCumulative Effect, Period of Adoption, Adjustment	Common Stock	Paid-In Capital	Common Stock in Treasury	Accumulated Other Comprehensive Loss	Retained (Deficit) Earnings	Retained (Deficit) EarningsCumulative Effect, Period of Adoption, Adjustment	Non-controlling Interest in Subsidiaries
Beginning balance (in shares) at Mar. 31, 2020					69,810		491
Beginning balance at Mar. 31, 2020	$ 537,485	$ (779)	$ 525,723	$ (779)	$ 11,555	$ 827,573	$ (10,461)	$ (35,325)	$ (267,619)	$ (779)	$ 11,762
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	151,273		150,702						150,702		571
Other comprehensive income	5,556		4,899					4,899			657
Redeemable convertible preferred stock dividends	(2,695)		(2,695)						(2,695)
Common stock dividends	(12,620)		(12,620)						(12,620)
Allocation of ESOP shares to participants for compensation	10,340		10,340			10,340
Exercise of common stock options (in shares)					152
Exercise of common stock options	3,277		3,277		$ 2	3,275
Restricted stock awards (in shares)					130		9
Restricted stock awards	(397)		(397)		$ 1		$ (398)
Stock-based compensation expense	11,095		11,095			11,095
ESOP distribution in common stock (in shares)					410
ESOP distribution in common stock	6,657		6,657		$ 4	6,653
Other	318		318			318
Ending balance (in shares) at Sep. 30, 2020					70,502		500
Ending balance at Sep. 30, 2020	$ 709,510		696,520		$ 11,562	859,254	$ (10,859)	(30,426)	(133,011)		12,990
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13 [Member]
Beginning balance (in shares) at Jun. 30, 2020					69,973		500
Beginning balance at Jun. 30, 2020	$ 614,589		602,306		$ 11,557	839,765	$ (10,853)	(32,494)	(205,669)		12,283
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	80,605		80,236						80,236		369
Other comprehensive income	2,406		2,068					2,068			338
Redeemable convertible preferred stock dividends	(1,329)		(1,329)						(1,329)
Common stock dividends	(6,249)		(6,249)						(6,249)
Allocation of ESOP shares to participants for compensation	6,304		6,304			6,304
Exercise of common stock options (in shares)					59
Exercise of common stock options	1,037		1,037		$ 1	1,036
Restricted stock awards (in shares)					60
Restricted stock awards	(6)		(6)				$ (6)
Stock-based compensation expense	5,496		5,496			5,496
ESOP distribution in common stock (in shares)					410
ESOP distribution in common stock	6,657		6,657		$ 4	6,653
Ending balance (in shares) at Sep. 30, 2020					70,502		500
Ending balance at Sep. 30, 2020	709,510		696,520		$ 11,562	859,254	$ (10,859)	(30,426)	(133,011)		12,990
Beginning balance (in shares) at Mar. 31, 2021					72,071		501
Beginning balance at Mar. 31, 2021	833,515		819,784		$ 11,578	918,587	$ (10,959)	(24,220)	(75,202)		13,731
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	153,435		151,346						151,346		2,089
Other comprehensive income	(1,365)		(1,800)					(1,800)			435
Redeemable convertible preferred stock dividends	(3,097)		(3,097)						(3,097)
Common stock dividends	(15,661)		(15,661)						(15,661)
Dividends paid to noncontrolling interest holder	$ (1,471)										(1,471)
Share repurchases (in shares)	2,600						2,574
Share repurchases	$ (292,000)		(292,000)				$ (292,000)
Allocation of ESOP shares to participants for compensation	22,149		22,149			22,149
Exercise of common stock options (in shares)					124
Exercise of common stock options	3,180		3,180		$ 1	3,179
Restricted stock awards (in shares)					129		29
Restricted stock awards	(3,230)		(3,230)		$ 1		$ (3,231)
Performance-based restricted stock units (in shares)					245		92
Performance-based restricted stock units	(9,743)		(9,743)		$ 2		$ (9,745)
Stock-based compensation expense	12,269		12,269			12,269
ESOP distribution in common stock (in shares)					764
ESOP distribution in common stock	12,412		12,412		$ 8	12,404
Other	(390)		(390)			(390)
Ending balance (in shares) at Sep. 30, 2021					73,333		3,196
Ending balance at Sep. 30, 2021	$ 710,003		695,219		$ 11,590	968,198	$ (315,935)	(26,020)	57,386		14,784
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13 [Member]
Beginning balance (in shares) at Jun. 30, 2021					73,227		1,678
Beginning balance at Jun. 30, 2021	$ 806,304		791,779		$ 11,589	950,963	$ (139,313)	(22,794)	(8,666)		14,525
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	76,312		75,359						75,359		953
Other comprehensive income	(3,406)		(3,226)					(3,226)			(180)
Redeemable convertible preferred stock dividends	(1,547)		(1,547)						(1,547)
Common stock dividends	(7,760)		(7,760)						(7,760)
Dividends paid to noncontrolling interest holder	$ (514)										(514)
Share repurchases (in shares)	1,500						1,518
Share repurchases	$ (176,622)		(176,622)				$ (176,622)
Allocation of ESOP shares to participants for compensation	10,085		10,085			10,085
Exercise of common stock options (in shares)					76
Exercise of common stock options	1,844		1,844		$ 1	1,843
Restricted stock awards (in shares)					30
Restricted stock awards	0		0
Stock-based compensation expense	5,618		5,618			5,618
Other	(311)		(311)			(311)
Ending balance (in shares) at Sep. 30, 2021					73,333		3,196
Ending balance at Sep. 30, 2021	$ 710,003		$ 695,219		$ 11,590	$ 968,198	$ (315,935)	$ (26,020)	$ 57,386		$ 14,784

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Common stock dividends per share	$ 0.11	$ 0.09	$ 0.22	$ 0.18

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Mezzanine Equity - USD ($) shares in Thousands, $ in Thousands	Total	Redeemable Convertible Preferred Stock	Deferred Compensation - Unearned ESOP Shares	Total Mezzanine Equity
Beginning Balance, Shares at Mar. 31, 2020		21,562	1,850
Beginning Balance, Value at Mar. 31, 2020		$ 269,529	$ (22,432)	$ 247,097
Increase (Decrease) in Temporary Equity [Roll Forward]
Allocation of ESOP shares to participants for compensation (in shares)			(452)
Allocation of ESOP shares to participants for compensation	$ 10,340		$ 5,653	5,653
ESOP distribution in common stock, Shares		532
ESOP distribution in common stock		$ (6,657)		(6,657)
Ending Balance, Shares at Sep. 30, 2020		21,030	1,398
Ending Balance, Value at Sep. 30, 2020		$ 262,872	$ (16,779)	246,093
Beginning Balance, Shares at Jun. 30, 2020		21,562	1,624
Beginning Balance, Value at Jun. 30, 2020		$ 269,529	$ (19,605)	249,924
Increase (Decrease) in Temporary Equity [Roll Forward]
Allocation of ESOP shares to participants for compensation (in shares)			(226)
Allocation of ESOP shares to participants for compensation	6,304		$ 2,826	2,826
ESOP distribution in common stock, Shares		(532)
ESOP distribution in common stock		$ (6,657)		(6,657)
Ending Balance, Shares at Sep. 30, 2020		21,030	1,398
Ending Balance, Value at Sep. 30, 2020		$ 262,872	$ (16,779)	246,093
Beginning Balance, Shares at Mar. 31, 2021		19,275	966
Beginning Balance, Value at Mar. 31, 2021	229,911	$ 240,944	$ (11,033)	229,911
Increase (Decrease) in Temporary Equity [Roll Forward]
Allocation of ESOP shares to participants for compensation (in shares)			(322)
Allocation of ESOP shares to participants for compensation	22,149		$ 4,019	4,019
ESOP distribution in common stock, Shares		(993)
ESOP distribution in common stock		$ (12,412)		(12,412)
Ending Balance, Shares at Sep. 30, 2021		18,282	644
Ending Balance, Value at Sep. 30, 2021	221,518	$ 228,532	$ (7,014)	221,518
Beginning Balance, Shares at Jun. 30, 2021		18,282	799
Beginning Balance, Value at Jun. 30, 2021		$ 228,532	$ (8,942)	219,590
Increase (Decrease) in Temporary Equity [Roll Forward]
Allocation of ESOP shares to participants for compensation (in shares)			155
Allocation of ESOP shares to participants for compensation	10,085		$ 1,928	1,928
Ending Balance, Shares at Sep. 30, 2021		18,282	644
Ending Balance, Value at Sep. 30, 2021	$ 221,518	$ 228,532	$ (7,014)	$ 221,518

Background and Summary of Signi

Background and Summary of Significant Accounting Policies	6 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Background and Summary of Significant Accounting Policies	BACKGROUND AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Description of Business - Advanced Drainage Systems, Inc. and subsidiaries (collectively referred to as “ADS” or the “Company”), incorporated in Delaware, designs, manufactures and markets innovative water management solutions in the stormwater and on-site septic waste water industries, providing superior drainage solutions for use in the construction and agriculture marketplace. ADS’s products are used across a broad range of end markets and applications, including non-residential, infrastructure and agriculture applications. The Company is managed and reports results of operations in three reportable segments: Pipe, Infiltrator Water Technologies Ultimate Holdings, Inc ("Infiltrator") and International. The Company also reports the results of its Allied Products and all other business segments as Allied Products and Other. Historically, sales of the Company’s products have been higher in the first and second quarters of each fiscal year due to favorable weather and longer daylight conditions accelerating construction activity during these periods. Seasonal variations in operating results may also be impacted by inclement weather conditions, such as cold or wet weather, which can delay projects. Basis of Presentation - The Company prepares its Condensed Consolidated Financial Statements in accordance with accounting principles generally accepted in the United States of America (“GAAP”). The Condensed Consolidated Balance Sheet as of March 31, 2021 was derived from audited financial statements included in the Annual Report on Form 10-K for the year ended March 31, 2021 (“Fiscal 2021 Form 10-K”). The accompanying unaudited Condensed Consolidated Financial Statements contain all adjustments, of a normal recurring nature, necessary to present fairly its financial position as of September 30, 2021 and the results of operations for the three and six months ended September 30, 2021 and cash flows for the six months ended September 30, 2021. The interim Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements, including the notes thereto, filed in the Company’s Fiscal 2021 Form 10-K. Principles of Consolidation - The Condensed Consolidated Financial Statements include the Company, its wholly-owned subsidiaries, its majority-owned subsidiaries and variable interest entities (“VIEs”) of which the Company is the primary beneficiary. The Company uses the equity method of accounting for equity investments where it exercises significant influence but does not hold a controlling financial interest. Such investments are recorded in Other assets in the Condensed Consolidated Balance Sheets and the related equity earnings from these investments are included in Equity in net income of unconsolidated affiliates in the Condensed Consolidated Statements of Operations. All intercompany balances and transactions have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the fiscal 2022 presentation. Recent Accounting Guidance Recently Adopted Accounting Guidance Standard Adoption ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes In December 2019, the FASB issued an ASU to simplify the accounting for income taxes by removing certain exceptions to the general principles in ASC 740, Income Taxes and improve the comparability of financial statements. The Company adopted this standard effective April 1, 2021. The Company’s adoption of the standard had no impact on the Company’s Condensed Consolidated Financial Statements.

Revenue Recognition

Revenue Recognition	6 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	REVENUE RECOGNITION Revenue Disaggregation - The Company disaggregates net sales by Domestic, International and Infiltrator and further disaggregates Domestic and International by product type, consistent with its reportable segment disclosure. This disaggregation level best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Refer to “Note 12. Business Segments Information” for the Company’s disaggregation of Net sales by reportable segment. Contract Balances - The Company recognizes a contract asset representing the Company’s right to recover products upon the receipt of returned products and a contract liability for the customer refund. The following table presents the balance of the Company’s contract asset and liability as of the periods presented: September 30, March 31, (In thousands) Contract asset - product returns $ 1,078 $ 694 Refund liability 2,392 1,801

Leases

Leases	6 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	LEASES Nature of the Company’s Leases - The Company has operating and finance leases for plants, yards, corporate offices, tractors, trailers and other equipment. The Company’s leases have remaining terms of less than one year to 30 years. A portion of the Company’s yard leases include an option to extend the leases for up to five years. The Company has included renewal options which are reasonably certain to be exercised in its right-of-use assets and lease liabilities. Master Lease Agreement – In May 2021, the Company entered into a Master Lease Agreement and an Interim Funding Agreement with Fifth Third Bank, National Association, (“Fifth Third”) to finance its procurement of material handling equipment, trucks and trailers (the “Master Lease Agreement”). The Master Lease Agreement and Interim Funding Agreement have a combined initial capacity of $65.0 million. Financings will either bear interest at a fixed rental amount or at a rate based on the London Interbank Offered Rate plus the applicable margin. As of September 30, 2021, the Company had lease financings of $5.5 million outstanding under the agreements.

Inventories

Inventories	6 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories as of the periods presented consisted of the following: September 30, March 31, (In thousands) Raw materials $ 147,584 $ 75,294 Finished goods 277,660 225,667 Total inventories $ 425,244 $ 300,961

Fair Value Measurements and Der

Fair Value Measurements and Derivative Transactions	6 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements and Derivative Transactions	FAIR VALUE MEASUREMENTS AND DERIVATIVE TRANSACTIONS The Company uses commodity options in the form of collars and swaps and has previously used interest rate swaps and foreign currency forward contracts to manage its various exposures to interest rate, commodity price fluctuations and foreign currency exchange rate fluctuations. Mark-to-market adjustments for changes in fair value and contract settlement gains and losses for collars, commodity swaps and foreign currency forward contracts are recorded in the Condensed Consolidated Statements of Operations in Derivative (gains) loss and other (income) expense, net. When applying fair value principles in the valuation of assets and liabilities, the Company is required to maximize the use of quoted market prices and minimize the use of unobservable inputs. The Company has not changed its valuation techniques used in measuring the fair value of any financial assets or liabilities during the fiscal periods presented. The fair value estimates take into consideration the credit risk of both the Company and its counterparties. When active market quotes are not available for financial assets and liabilities, the Company uses industry standard valuation models. Where applicable, these models project future cash flows and discount the future amounts to a present value using market-based observable inputs including credit risk, interest rate curves, foreign currency rates and forward and spot prices for currencies. In circumstances where market-based observable inputs are not available, management judgment is used to develop assumptions to estimate fair value. Recurring Fair Value Measurements - The assets and liabilities carried at fair value as of the periods presented were as follows: September 30, 2021 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 1,715 — $ 1,715 — Total assets at fair value on a recurring basis $ 1,715 — $ 1,715 — Liabilities: Derivative liabilities – diesel fuel contracts $ 107 — $ 107 — Total liabilities at fair value on a recurring basis $ 107 — $ 107 — March 31, 2021 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 1,194 — $ 1,194 — Total assets at fair value on a recurring basis $ 1,194 — $ 1,194 — Liabilities: Derivative liabilities - diesel fuel contracts $ 32 — $ 32 — Total liabilities at fair value on a recurring basis $ 32 — $ 32 — For the six months ended September 30, 2021 and 2020, respectively, there were no transfers in or out of Levels 1, 2 or 3. The Company recorded net (gains) and net losses on mark-to-market adjustments for changes in the fair value of derivatives contracts as well as net (gains) and net losses on the settlement of derivative contracts as follows: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Diesel fuel option collars $ 229 $ (373) $ (446) $ (1,455) Total net unrealized mark-to-market loss (gains) $ 229 $ (373) $ (446) $ (1,455) Diesel fuel option collars (752) 477 (1,266) 1,317 Total net realized (gain) loss $ (752) $ 477 $ (1,266) $ 1,317 Valuation of Debt - The carrying amounts of current financial assets and liabilities approximate fair value because of the immediate or short-term maturity of these items, or in the case of derivative instruments, because they are recorded at fair value. The following table presents the carrying and fair value of the Company’s Senior Notes (as defined below and further discussed in “Note 8. Debt”) for the periods presented: September 30, 2021 March 31, 2021 Fair Value Carrying Value Fair Value Carrying Value (In thousands) Senior Notes $ 365,428 $ 350,000 $ 367,633 $ 350,000 The fair value of the Senior Notes was determined based on a quoted market data for the Company’s Senior Notes. The categorization of the framework used to evaluate the Senior Notes is considered Level 2. The Company believes the carrying amount on the remaining long-term debt, including the Term Loan Facility and Revolving Credit Facility, is not materially different from its fair value as the interest rates and terms of the borrowings are similar to currently available borrowings.

Net Income Per Share and Stockh

Net Income Per Share and Stockholders' Equity	6 Months Ended
	Sep. 30, 2021
Net Income Per Share And Stockholders Equity [Abstract]
Net Income Per Share and Stockholders' Equity	NET INCOME PER SHARE AND STOCKHOLDERS' EQUITY The Company is required to apply the two-class method to compute both basic and diluted net income per share. The two-class method is an earnings allocation formula that treats participating securities as having rights to earnings that would otherwise have been available to common stockholders. The following table presents information necessary to calculate net income per share for the periods presented, as well as potentially dilutive securities excluded from the weighted average number of diluted common shares outstanding because their inclusion would have been anti-dilutive: Three Months Ended Six Months Ended (In thousands, except per share data) 2021 2020 2021 2020 NET INCOME PER SHARE—BASIC: Net income attributable to ADS $ 75,359 $ 80,236 $ 151,346 $ 150,702 Adjustments for: Dividends to participating securities (1,636) (1,329) (3,276) (2,697) Net income available to common stockholders and participating securities 73,723 78,907 148,070 148,005 Undistributed income allocated to participating securities (10,494) (12,760) (21,430) (24,025) Net income available to common stockholders – Basic $ 63,229 $ 66,147 $ 126,640 $ 123,980 Weighted average number of common shares outstanding – Basic 70,464 69,843 70,993 69,612 Net income per common share – Basic $ 0.90 $ 0.95 $ 1.78 $ 1.78 NET INCOME PER SHARE—DILUTED: Net income available to common stockholders – Diluted $ 63,229 $ 66,147 $ 126,640 $ 123,980 Weighted average number of common shares outstanding – Basic 70,464 69,843 70,993 69,612 Assumed restricted stock - nonparticipating 223 196 251 185 Assumed exercise of stock options 914 716 928 662 Assumed performance units 323 — 442 — Weighted average number of common shares outstanding – Diluted 71,924 70,755 72,614 70,459 Net income per common share – Diluted $ 0.88 $ 0.93 $ 1.74 $ 1.76 Potentially dilutive securities excluded as anti-dilutive 13,356 14,892 13,729 15,279 Stockholders’ Equity – During the three and six months ended September 30, 2021, the Company repurchased 1.5 million and 2.6 million shares of common stock, respectively, at a cost of $176.6 million and $292.0 million, respectively. The repurchases were made under the Board of Directors’ authorization in May 2021 to repurchase up to an additional $250 million, in addition to the $42 million previously authorized, of ADS common stock in accordance with applicable securities laws. As of September 30, 2021, the Company has utilized all of the common stock repurchase authorization. The repurchase program does not obligate the Company to acquire any particular amount of common stock and may be suspended or terminated at any time at the Company’s discretion. On October 1, 2021, ADS completed an ESOP distribution of 1.1 million common shares to participants, which will be recorded in the third quarter of fiscal 2022. The distribution will reduce the balance of Redeemable preferred common stock by $17.6 million and increase Paid-in capital.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS ADS Mexicana - ADS conducts business in Mexico and Central America through its joint venture ADS Mexicana, S.A. de C.V. (together with its affiliate ADS Corporativo, S.A. de C.V., “ADS Mexicana”). ADS owns 51% of the outstanding stock of ADS Mexicana and consolidates ADS Mexicana for financial reporting purposes. On June 22, 2018, the Company and ADS Mexicana entered into an Intercompany Revolving Credit Promissory Note (the “Intercompany Note”) with a borrowing capacity of $12.0 million. The Intercompany Note matures on June 22, 2022. The Intercompany Note indemnifies the ADS Mexicana joint venture partner for 49% of any unpaid borrowing. The interest rates under the Intercompany Note are determined by certain base rates or London Interbank Offered Rate (“LIBOR”) plus an applicable margin based on the Leverage Ratio. As of September 30, 2021 and March 31, 2021, there were no borrowings outstanding under the Intercompany Note. South American Joint Venture - The Tuberias Tigre - ADS Limitada joint venture (the “South American Joint Venture”) manufactures and sells HDPE corrugated pipe in certain South American markets. ADS owns 50% of the South American Joint Venture. ADS is the guarantor of 50% of the South American Joint Venture’s credit arrangement, and the debt guarantee is shared equally with the joint venture partner. The Company’s maximum potential obligation under this guarantee is $11.0 million as of September 30, 2021. The maximum borrowings permitted under the South American Joint Venture’s credit facility are $22.0 million. The Company does not anticipate any required contributions related to the balance of this credit arrangement. As of September 30, 2021 and March 31, 2021, the outstanding principal balances of the credit facility including letters of credit were $8.9 million and $10.0 million, respectively. As of September 30, 2021, there were no U.S. dollar denominated loans. The weighted average interest rate as of September 30, 2021 was 4.4% on Chilean peso denominated loans.

Debt

Debt	6 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	DEBT Long-term debt as of the periods presented consisted of the following: September 30, March 31, (In thousands) Term Loan Facility $ 437,750 $ 441,250 Senior Notes 350,000 350,000 Revolving Credit Facility 122,600 — Total 910,350 791,250 Unamortized debt issuance costs (1,839) (2,030) Current maturities (7,000) (7,000) Long-term debt obligations $ 901,511 $ 782,220 Senior Secured Credit Facilities – In July 2019, the Company entered into the credit agreement (the “Base Credit Agreement”) by and among the Company, as borrower, Barclays Bank PLC, as administrative agent, the several lenders from time to time party thereto. In September 2019, the Company amended the Base Credit Agreement (as amended the “Senior Secured Credit Facility”). The Senior Secured Credit Facility provides for a term loan facility in an initial aggregate principal amount of $700 million (the “Term Loan Facility”), a revolving credit facility in an initial aggregate principal amount of up to $350 million (the “Revolving Credit Facility”), a letter of credit sub-facility in the initial aggregate available amount of up to $50 million, as a sublimit of such Revolving Credit Facility (the “L/C Facility”) and a swing line sub-facility in the aggregate available amount of up to $50 million, as a sublimit of the Revolving Credit Facility (together with the Term Loan Facility, the Revolving Credit Facility and the L/C Facility, the “Senior Secured Credit Facility”). During the six months ended September 30, 2021, the Company received proceeds of $146.8 million from the Revolving Credit Facility and repaid $3.5 million of the Term Loan Facility and $24.2 million of the Revolving Credit Facility. Letters of credit outstanding at September 30, 2021 and March 31, 2021 amount to $12.5 million and $11.0 million, respectively, and reduced the availability of the Revolving Credit Facility. Senior Notes – On September 23, 2019, the Company issued $350.0 million aggregate principal amount of 5.0% senior notes due 2027 (the “Senior Notes”) pursuant to an Indenture, dated September 23, 2019 (the “Indenture”), among the Company, the guarantors party thereto (the “Guarantors”) and U.S. Bank National Association, as Trustee (the “Trustee”). The Senior Notes are guaranteed by each of the Company’s present and future direct and indirect wholly owned domestic subsidiaries that is a guarantor under the Company's Senior Secured Credit Facility. The Senior Notes were offered and sold either to persons reasonably believed to be “qualified institutional buyers” pursuant to Rule 144A under the Securities Act of 1933 (the “Securities Act”) or to persons outside the United States under Regulation S of the Securities Act.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Purchase Commitments The Company has historically secured supplies of resin raw material by agreeing to purchase quantities during a future given period at a fixed price. These purchase contracts typically ranged from 1 to 12 months and occur in the ordinary course of business. The Company also enters into equipment purchase contracts with manufacturers. The Company does not have any outstanding purchase commitments as of September 30, 2021. Litigation and Other Proceedings – The Company is involved from time to time in various legal proceedings that arise in the ordinary course of business, including but not limited to commercial disputes, environmental matters, employee related claims, intellectual property disputes and litigation in connection with transactions including acquisitions and divestitures. The Company does not believe that such litigation, claims, and administrative proceedings will have a material adverse impact on the Company’s financial position or results of operations. The Company records a liability when a loss is considered probable, and the amount can be reasonably estimated.

Income Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXESThe Company’s effective tax rate will vary based on a variety of factors, including overall profitability, the geographical mix of income before taxes and related tax rates in jurisdictions where it operates and other one-time charges, as well as the occurrence of discrete events. For the three months ended September 30, 2021 and 2020, the Company utilized an effective tax rate of 26.1% and 28.3%, respectively, to calculate its provision for income taxes. State and local income taxes and the Company’s Employee Stock Ownership Plan (“ESOP”) increased the effective rate for the three months ended September 30, 2021 and 2020. Additionally, discrete income tax benefits related to the stock-based compensation windfall and other items decreased the rate for the three months ended September 30, 2021.For the six months ended September 30, 2021 and 2020, the Company utilized an effective tax rate of 25.8% and 28.1%, respectively,to calculate its provision for income taxes. State and local income taxes and the Company’s ESOP increased the effective rate for the the six months ended September 30, 2021 and 2020. Additionally, discrete income tax benefits related to the stock-based compensation windfall and other items decreased the rate for the six months ended September 30, 2021

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION ADS has several programs for stock-based payments to employees and non-employee members of its Board of Directors, including stock options, performance-based restricted stock units and restricted stock. Equity-classified restricted stock awards are measured based on the grant-date estimated fair value of each award. The Company accounts for all restricted stock granted to Directors as equity-classified awards. The Company recognized stock-based compensation expense in the following line items of the Condensed Consolidated Statements of Operations for the periods presented: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Component of income before income taxes: Cost of goods sold $ 685 $ 565 $ 1,319 $ 966 Selling, general and administrative expenses 4,933 4,931 10,950 10,129 Total stock-based compensation expense $ 5,618 $ 5,496 $ 12,269 $ 11,095 The following table summarizes stock-based compensation expense by award type for the periods presented: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Stock-based compensation expense: Stock Options $ 860 $ 750 $ 1,613 $ 1,631 Restricted Stock 1,520 1,344 2,879 2,761 Performance-based Restricted Stock Units 2,773 3,070 6,961 6,054 Non-Employee Directors 465 332 816 649 Total stock-based compensation expense $ 5,618 $ 5,496 $ 12,269 $ 11,095 2017 Omnibus Plan On May 24, 2017, the Board of Directors approved the 2017 Omnibus Incentive Plan (the “2017 Incentive Plan”) which was approved by the Company’s stockholders on July 17, 2017. The 2017 Incentive Plan provides for the issuance of a maximum of 5.0 million shares of the Company’s common stock for awards made thereunder, which awards may consist of stock options, restricted stock, restricted stock units, stock appreciation rights, phantom stock, cash-based awards, performance awards (which may take the form of performance cash, performance units or performance shares) or other stock-based awards. Restricted Stock - During the three and six months ended September 30, 2021, the Company granted less than 0.1 million shares and 0.1 million shares of restricted stock with a grant date fair value of $2.0 million and $7.3 million, respectively. Performance-based Restricted Stock Units (" Performance Units") – During the six months ended September 30, 2021, the Company granted 0.1 million performance share units were granted at a grant date fair value of $5.3 million. Options - During the six months ended September 30, 2021, The Company granted 0.1 million nonqualified stock options under the 2017 Incentive Plan with a grant date fair value of $4.2 million. The Company estimates the fair value of stock options using a Black-Scholes option-pricing model. The following table summarizes the assumptions used to estimate the fair value of stock-options during the periods presented: Six Months Ended Common stock price $105.82 Expected stock price volatility 41.0% Risk-free interest rate 1.1% Weighted-average expected option life (years) 6.0 Dividend yield 0.3%

Business Segments Information

Business Segments Information	6 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Business Segments Information	BUSINESS SEGMENTS INFORMATION The Company operates its business in three distinct reportable segments: “Pipe”, “International” and “Infiltrator.” “Allied Products & Other” represents the Company’s Allied Products and all other business segments. “Pipe” and “Allied Products & Other” were previously included as Domestic. The Chief Operating Decision Maker (the “CODM”) evaluates segment reporting based on Net Sales and Segment Adjusted Gross Profit. The Company calculated Segment Adjusted Gross Profit as net sales less costs of goods sold, depreciation and amortization, stock-based compensation and non-cash charges. A measure of assets is not applicable, as segment assets are not regularly reviewed by the CODM for evaluating performance or allocating resources. Pipe – The Pipe segment manufactures and markets high performance thermoplastic corrugated pipe throughout the United States. The Company maintains and serves these markets through product distribution relationships with many of the largest national and independent waterworks distributors, buying groups and co-ops, major national retailers as well as an extensive network of hundreds of small to medium-sized distributors across the United States. Products include single wall pipe, N-12 HDPE pipe sold into the Storm sewer, Infrastructure and Agriculture markets, High Performance polypropylene pipe sold into the Storm sewer, Infrastructure and sanitary sewer markets. Products are designed primarily for storm water management in the construction and infrastructure marketplace across a broad range of end markets and applications, including non-residential, residential, agriculture and infrastructure. Products are manufactured using HDPE and polypropylene plastic material. Infiltrator – Infiltrator is a leading national provider of plastic leach field chambers and systems, septic tanks and accessories, primarily for use in residential applications. Infiltrator products are used in on-site septic wastewater treatment systems in the United States and Canada. International – The International segment manufactures and markets pipe and allied products in certain regions outside of the United States, including Company owned facilities in Canada, subsidiaries that distribute to Europe and the Middle East, exports and through the Company’s joint ventures with local partners in Mexico and South America. The Company’s Mexican joint venture, ADS Mexicana, primarily serves the Mexican and Central American markets, while its South American Joint Venture, Tigre-ADS, is the primary channel to serve the South American markets. The Company’s International product lines include single wall pipe, N-12 HDPE pipe, high performance PP pipe and certain geographies also sell our broad line of Allied Products. Allied Products & Other – Allied Products and Other manufactures and markets products throughout the United States. Products include StormTech, Nyloplast, ARC Septic Chambers, Inserta Tee, BaySaver filters and water quality structures, Fittings, and FleXstorm. The Company maintains and serves these markets through product distribution relationships with many of the largest national and independent waterworks distributors, major national retailers as well as an extensive network of hundreds of small to medium-sized distributors across the United States. The Company also sells through a broad variety of buying groups and co-ops in the United States. The Company aggregates operating segments within the Allied Products & Other segment disclosure. None of the operating segments within the Allied Products & Other businesses segment disclosure exceeds the quantitative thresholds for separate segment reporting. The following table sets forth reportable segment information with respect to the amount of Net sales contributed by each class of similar products for the periods presented: Three Months Ended September 30, 2021 September 30, 2020 (In thousands) Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 384,521 $ (2,668) $ 381,853 $ 292,133 $ (1,637) $ 290,496 Infiltrator 145,911 (22,412) 123,499 105,986 (18,692) 87,294 International International - Pipe 50,141 (5,170) 44,971 35,592 (896) 34,696 International - Allied Products & Other 13,433 — 13,433 13,706 — 13,706 Total International 63,574 (5,170) 58,404 49,298 (896) 48,402 Allied Products & Other 145,719 (3,004) 142,715 117,995 — 117,995 Intersegment Eliminations (33,254) 33,254 — (21,225) 21,225 — Total Consolidated $ 706,471 $ — $ 706,471 $ 544,187 $ — $ 544,187 Six Months Ended September 30, 2021 September 30, 2020 (In thousands) Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 758,531 $ (4,571) $ 753,960 $ 565,785 $ (3,482) $ 562,303 Infiltrator 272,653 (41,449) 231,204 208,139 (36,760) 171,379 International International - Pipe 100,979 (8,084) 92,895 62,542 (896) 61,646 International - Allied Products & Other 27,961 — 27,961 22,585 — 22,585 Total International 128,940 (8,084) 120,856 85,127 (896) 84,231 Allied Products & Other 272,755 (3,004) 269,751 234,913 — 234,913 Intersegment Eliminations (57,108) 57,108 — (41,138) 41,138 — Total Consolidated $ 1,375,771 $ — $ 1,375,771 $ 1,052,826 $ — $ 1,052,826 The following sets forth certain financial information attributable to the reportable segments for the periods presented: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Segment Adjusted Gross Profit Pipe $ 82,472 $ 100,496 $ 166,615 $ 191,095 Infiltrator 58,847 53,105 118,249 101,033 International 15,077 14,582 36,455 25,990 Allied Products & Other 67,979 60,380 131,278 120,848 Intersegment Eliminations 1,479 372 1,465 14 Total $ 225,854 $ 228,935 $ 454,062 $ 438,980 Depreciation and Amortization Pipe $ 12,026 $ 11,543 $ 24,061 $ 22,903 Infiltrator 3,375 3,005 6,811 6,138 International 1,290 1,302 2,748 2,600 Allied Products & Other (a) 17,503 19,928 35,230 39,918 Total $ 34,194 $ 35,778 $ 68,850 $ 71,559 Capital Expenditures Pipe $ 12,809 $ 3,911 $ 22,639 $ 8,142 Infiltrator 22,134 13,781 35,160 17,979 International 1,264 297 1,514 747 Allied Products & Other (a) 2,011 675 4,451 2,091 Total $ 38,218 $ 18,664 $ 63,764 $ 28,959 (a) Includes depreciation, amortization and capital expenditures not allocated to a reportable segment. The amortization expense of Infiltrator intangible assets acquired is included in Allied Products & Other. Reconciliation of Gross Profit to Segment Adjusted Gross profit Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Reconciliation of Segment Adjusted Gross Profit: Total Gross Profit $ 200,057 $ 205,857 $ 401,178 $ 394,360 Depreciation and Amortization 17,250 16,463 34,782 32,886 ESOP and stock-based compensation expense 8,547 6,598 18,102 11,537 COVID-19 related costs (a) — 17 — 197 Total Segment Adjusted Gross Profit $ 225,854 $ 228,935 $ 454,062 $ 438,980 (a) Includes expenses directly related to our response to the COVID-19 pandemic, including adjustments to our pandemic pay program and expenses associated with our third-party crisis management vendor.

Subsequent Events

Subsequent Events	6 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Common Stock Dividend - During the third quarter of fiscal 2022, the Company declared a quarterly cash dividend of $0.11 per share of common stock. The dividend is payable on December 15, 2021 to stockholders of record at the close of business on December 1, 2021.

Background and Summary of Sig_2

Background and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation -
Principles of Consolidation	Principles of Consolidation - The Condensed Consolidated Financial Statements include the Company, its wholly-owned subsidiaries, its majority-owned subsidiaries and variable interest entities (“VIEs”) of which the Company is the primary beneficiary. The Company uses the equity method of accounting for equity investments where it exercises significant influence but does not hold a controlling financial interest. Such investments are recorded in Other assets in the Condensed Consolidated Balance Sheets and the related equity earnings from these investments are included in Equity in net income of unconsolidated affiliates in the Condensed Consolidated Statements of Operations. All intercompany balances and transactions have been eliminated in consolidation. Certain prior year amounts have been reclassified to conform to the fiscal 2022 presentation.
Recent Accounting Guidance	Recent Accounting Guidance Recently Adopted Accounting Guidance Standard Adoption ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes In December 2019, the FASB issued an ASU to simplify the accounting for income taxes by removing certain exceptions to the general principles in ASC 740, Income Taxes and improve the comparability of financial statements. The Company adopted this standard effective April 1, 2021. The Company’s adoption of the standard had no impact on the Company’s Condensed Consolidated Financial Statements.
Leases	Nature of the Company’s Leases - The Company has operating and finance leases for plants, yards, corporate offices, tractors, trailers and other equipment. The Company’s leases have remaining terms of less than one year to 30 years. A portion of the Company’s yard leases include an option to extend the leases for up to five years. The Company has included renewal options which are reasonably certain to be exercised in its right-of-use assets and lease liabilities. Master Lease Agreement – In May 2021, the Company entered into a Master Lease Agreement and an Interim Funding Agreement with Fifth Third Bank, National Association, (“Fifth Third”) to finance its procurement of material handling equipment, trucks and trailers (the “Master Lease Agreement”). The Master Lease Agreement and Interim Funding Agreement have a combined initial capacity of $65.0 million. Financings will either bear interest at a fixed rental amount or at a rate based on the London Interbank Offered Rate plus the applicable margin. As of September 30, 2021, the Company had lease financings of $5.5 million outstanding under the agreements.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Contract Asset and Liability	The following table presents the balance of the Company’s contract asset and liability as of the periods presented: September 30, March 31, (In thousands) Contract asset - product returns $ 1,078 $ 694 Refund liability 2,392 1,801

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Sep. 30, 2021
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories as of the periods presented consisted of the following: September 30, March 31, (In thousands) Raw materials $ 147,584 $ 75,294 Finished goods 277,660 225,667 Total inventories $ 425,244 $ 300,961

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Assets and Liabilities Carried at Fair Value	The assets and liabilities carried at fair value as of the periods presented were as follows: September 30, 2021 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 1,715 — $ 1,715 — Total assets at fair value on a recurring basis $ 1,715 — $ 1,715 — Liabilities: Derivative liabilities – diesel fuel contracts $ 107 — $ 107 — Total liabilities at fair value on a recurring basis $ 107 — $ 107 — March 31, 2021 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 1,194 — $ 1,194 — Total assets at fair value on a recurring basis $ 1,194 — $ 1,194 — Liabilities: Derivative liabilities - diesel fuel contracts $ 32 — $ 32 — Total liabilities at fair value on a recurring basis $ 32 — $ 32 —
Schedule of Derivative Instruments Included in Trading Activities	The Company recorded net (gains) and net losses on mark-to-market adjustments for changes in the fair value of derivatives contracts as well as net (gains) and net losses on the settlement of derivative contracts as follows: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Diesel fuel option collars $ 229 $ (373) $ (446) $ (1,455) Total net unrealized mark-to-market loss (gains) $ 229 $ (373) $ (446) $ (1,455) Diesel fuel option collars (752) 477 (1,266) 1,317 Total net realized (gain) loss $ (752) $ 477 $ (1,266) $ 1,317
Summary of Carrying And Fair Value of Senior Notes	The following table presents the carrying and fair value of the Company’s Senior Notes (as defined below and further discussed in “Note 8. Debt”) for the periods presented: September 30, 2021 March 31, 2021 Fair Value Carrying Value Fair Value Carrying Value (In thousands) Senior Notes $ 365,428 $ 350,000 $ 367,633 $ 350,000

Net Income Per Share and Stoc_2

Net Income Per Share and Stockholders' Equity (Tables)	6 Months Ended
	Sep. 30, 2021
Net Income Per Share And Stockholders Equity [Abstract]
Summary of Net Income Per Share	The following table presents information necessary to calculate net income per share for the periods presented, as well as potentially dilutive securities excluded from the weighted average number of diluted common shares outstanding because their inclusion would have been anti-dilutive: Three Months Ended Six Months Ended (In thousands, except per share data) 2021 2020 2021 2020 NET INCOME PER SHARE—BASIC: Net income attributable to ADS $ 75,359 $ 80,236 $ 151,346 $ 150,702 Adjustments for: Dividends to participating securities (1,636) (1,329) (3,276) (2,697) Net income available to common stockholders and participating securities 73,723 78,907 148,070 148,005 Undistributed income allocated to participating securities (10,494) (12,760) (21,430) (24,025) Net income available to common stockholders – Basic $ 63,229 $ 66,147 $ 126,640 $ 123,980 Weighted average number of common shares outstanding – Basic 70,464 69,843 70,993 69,612 Net income per common share – Basic $ 0.90 $ 0.95 $ 1.78 $ 1.78 NET INCOME PER SHARE—DILUTED: Net income available to common stockholders – Diluted $ 63,229 $ 66,147 $ 126,640 $ 123,980 Weighted average number of common shares outstanding – Basic 70,464 69,843 70,993 69,612 Assumed restricted stock - nonparticipating 223 196 251 185 Assumed exercise of stock options 914 716 928 662 Assumed performance units 323 — 442 — Weighted average number of common shares outstanding – Diluted 71,924 70,755 72,614 70,459 Net income per common share – Diluted $ 0.88 $ 0.93 $ 1.74 $ 1.76 Potentially dilutive securities excluded as anti-dilutive 13,356 14,892 13,729 15,279

Debt (Tables)

Debt (Tables)	6 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Long-term debt as of the periods presented consisted of the following: September 30, March 31, (In thousands) Term Loan Facility $ 437,750 $ 441,250 Senior Notes 350,000 350,000 Revolving Credit Facility 122,600 — Total 910,350 791,250 Unamortized debt issuance costs (1,839) (2,030) Current maturities (7,000) (7,000) Long-term debt obligations $ 901,511 $ 782,220

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Summary of Stock-based Compensation Expense	The Company recognized stock-based compensation expense in the following line items of the Condensed Consolidated Statements of Operations for the periods presented: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Component of income before income taxes: Cost of goods sold $ 685 $ 565 $ 1,319 $ 966 Selling, general and administrative expenses 4,933 4,931 10,950 10,129 Total stock-based compensation expense $ 5,618 $ 5,496 $ 12,269 $ 11,095 The following table summarizes stock-based compensation expense by award type for the periods presented: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Stock-based compensation expense: Stock Options $ 860 $ 750 $ 1,613 $ 1,631 Restricted Stock 1,520 1,344 2,879 2,761 Performance-based Restricted Stock Units 2,773 3,070 6,961 6,054 Non-Employee Directors 465 332 816 649 Total stock-based compensation expense $ 5,618 $ 5,496 $ 12,269 $ 11,095
Summary of Assumption Used to Estimate Fair Value of Stock Options	The following table summarizes the assumptions used to estimate the fair value of stock-options during the periods presented: Six Months Ended Common stock price $105.82 Expected stock price volatility 41.0% Risk-free interest rate 1.1% Weighted-average expected option life (years) 6.0 Dividend yield 0.3%

Business Segments Information (

Business Segments Information (Tables)	6 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Schedule of Revenue from Reportable Segments by Product Type	The following table sets forth reportable segment information with respect to the amount of Net sales contributed by each class of similar products for the periods presented: Three Months Ended September 30, 2021 September 30, 2020 (In thousands) Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 384,521 $ (2,668) $ 381,853 $ 292,133 $ (1,637) $ 290,496 Infiltrator 145,911 (22,412) 123,499 105,986 (18,692) 87,294 International International - Pipe 50,141 (5,170) 44,971 35,592 (896) 34,696 International - Allied Products & Other 13,433 — 13,433 13,706 — 13,706 Total International 63,574 (5,170) 58,404 49,298 (896) 48,402 Allied Products & Other 145,719 (3,004) 142,715 117,995 — 117,995 Intersegment Eliminations (33,254) 33,254 — (21,225) 21,225 — Total Consolidated $ 706,471 $ — $ 706,471 $ 544,187 $ — $ 544,187 Six Months Ended September 30, 2021 September 30, 2020 (In thousands) Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 758,531 $ (4,571) $ 753,960 $ 565,785 $ (3,482) $ 562,303 Infiltrator 272,653 (41,449) 231,204 208,139 (36,760) 171,379 International International - Pipe 100,979 (8,084) 92,895 62,542 (896) 61,646 International - Allied Products & Other 27,961 — 27,961 22,585 — 22,585 Total International 128,940 (8,084) 120,856 85,127 (896) 84,231 Allied Products & Other 272,755 (3,004) 269,751 234,913 — 234,913 Intersegment Eliminations (57,108) 57,108 — (41,138) 41,138 — Total Consolidated $ 1,375,771 $ — $ 1,375,771 $ 1,052,826 $ — $ 1,052,826
Schedule of Financial Information Attributable to Reportable Segments	The following sets forth certain financial information attributable to the reportable segments for the periods presented: Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Segment Adjusted Gross Profit Pipe $ 82,472 $ 100,496 $ 166,615 $ 191,095 Infiltrator 58,847 53,105 118,249 101,033 International 15,077 14,582 36,455 25,990 Allied Products & Other 67,979 60,380 131,278 120,848 Intersegment Eliminations 1,479 372 1,465 14 Total $ 225,854 $ 228,935 $ 454,062 $ 438,980 Depreciation and Amortization Pipe $ 12,026 $ 11,543 $ 24,061 $ 22,903 Infiltrator 3,375 3,005 6,811 6,138 International 1,290 1,302 2,748 2,600 Allied Products & Other (a) 17,503 19,928 35,230 39,918 Total $ 34,194 $ 35,778 $ 68,850 $ 71,559 Capital Expenditures Pipe $ 12,809 $ 3,911 $ 22,639 $ 8,142 Infiltrator 22,134 13,781 35,160 17,979 International 1,264 297 1,514 747 Allied Products & Other (a) 2,011 675 4,451 2,091 Total $ 38,218 $ 18,664 $ 63,764 $ 28,959 (a) Includes depreciation, amortization and capital expenditures not allocated to a reportable segment. The amortization expense of Infiltrator intangible assets acquired is included in Allied Products & Other.
Reconciliation of Gross Profit to Segment Adjusted Gross Profit	Reconciliation of Gross Profit to Segment Adjusted Gross profit Three Months Ended Six Months Ended 2021 2020 2021 2020 (In thousands) Reconciliation of Segment Adjusted Gross Profit: Total Gross Profit $ 200,057 $ 205,857 $ 401,178 $ 394,360 Depreciation and Amortization 17,250 16,463 34,782 32,886 ESOP and stock-based compensation expense 8,547 6,598 18,102 11,537 COVID-19 related costs (a) — 17 — 197 Total Segment Adjusted Gross Profit $ 225,854 $ 228,935 $ 454,062 $ 438,980 (a) Includes expenses directly related to our response to the COVID-19 pandemic, including adjustments to our pandemic pay program and expenses associated with our third-party crisis management vendor.

Background and Summary of Sig_3

Background and Summary of Significant Accounting Policies - Additional Information (Detail)	6 Months Ended
	Sep. 30, 2021segment
Accounting Policies [Abstract]
Number of reportable segments	3
Change in Accounting Principle, Accounting Standards Update, Adopted	true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect	false

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Contract Asset and Liability (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Contract asset - product returns	$ 1,078	$ 694
Refund liability	$ 2,392	$ 1,801

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
	Sep. 30, 2021	May 31, 2021
Lessee Lease Description [Line Items]
Unused borrowing capacity of lease		$ 65
Line of credit	$ 5.5
Minimum
Lessee Lease Description [Line Items]
Leases remaining term	1 year
Maximum
Lessee Lease Description [Line Items]
Leases remaining term	30 years
Maximum | Yard
Lessee Lease Description [Line Items]
Leases options to extend	5 years

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Inventory Disclosure [Abstract]
Raw materials	$ 147,584	$ 75,294
Finished goods	277,660	225,667
Total inventories	$ 425,244	$ 300,961

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Assets and Liabilities Carried at Fair Value (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
ASSETS
Total assets at fair value on a recurring basis	$ 1,715	$ 1,194
Liabilities [Abstract]
Total liabilities at fair value on a recurring basis	107	32
Level 2
ASSETS
Total assets at fair value on a recurring basis	1,715	1,194
Liabilities [Abstract]
Total liabilities at fair value on a recurring basis	107	32
Diesel Fuel Contracts
ASSETS
Derivative assets – diesel fuel contracts	1,715	1,194
Liabilities [Abstract]
Derivative liabilities – diesel fuel contracts	107	32
Diesel Fuel Contracts | Level 2
ASSETS
Derivative assets – diesel fuel contracts	1,715	1,194
Liabilities [Abstract]
Derivative liabilities – diesel fuel contracts	$ 107	$ 32

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - USD ($)	6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair value of assets and liabilities, additional transfers	$ 0	$ 0

Derivative Transactions - Sched

Derivative Transactions - Schedule of Cash Settlements and Net (Gains) and Net Losses on Mark-to-Market Adjustments for Changes in Fair Value of Derivative Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivatives, Fair Value [Line Items]
Total net unrealized mark-to-market loss (gains)	$ 229	$ (373)	$ (446)	$ (1,455)
Total net realized (gain) loss	(752)	477	(1,266)	1,317
Diesel fuel option collars
Derivatives, Fair Value [Line Items]
Total net unrealized mark-to-market loss (gains)	229	(373)	(446)	(1,455)
Total net realized (gain) loss	$ (752)	$ 477	$ (1,266)	$ 1,317

Fair Value Measurement - Summ_2

Fair Value Measurement - Summary of Carrying And Fair Value of Senior Notes (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Reported Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	$ 350,000	$ 350,000
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	$ 365,428	$ 367,633

Net Income Per Share and Stoc_3

Net Income Per Share and Stockholders' Equity - Summary of Net Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
NET INCOME PER SHARE—BASIC:
Net income attributable to ADS	$ 75,359	$ 80,236	$ 151,346	$ 150,702
Adjustments for:
Dividends to participating securities	(1,636)	(1,329)	(3,276)	(2,697)
Net income available to common stockholders and participating securities	73,723	78,907	148,070	148,005
Undistributed income allocated to participating securities	(10,494)	(12,760)	(21,430)	(24,025)
Net income available to common stockholders – Basic	$ 63,229	$ 66,147	$ 126,640	$ 123,980
Weighted average number of common shares outstanding – Basic	70,464	69,843	70,993	69,612
Net income per common share – Basic	$ 0.90	$ 0.95	$ 1.78	$ 1.78
NET INCOME PER SHARE—DILUTED:
Net income available to common stockholders – Diluted	$ 63,229	$ 66,147	$ 126,640	$ 123,980
Weighted average number of common shares outstanding – Basic	70,464	69,843	70,993	69,612
Weighted average number of common shares outstanding – Diluted	71,924	70,755	72,614	70,459
Net income per common share – Diluted	$ 0.88	$ 0.93	$ 1.74	$ 1.76
Potentially dilutive securities excluded as anti-dilutive	13,356	14,892	13,729	15,279
Exercise of Stock Options
NET INCOME PER SHARE—DILUTED:
Dilutive securities	914	716	928	662
Restricted Stock
NET INCOME PER SHARE—DILUTED:
Dilutive securities	323	0	442	0
Restricted Stock, Nonparticipating
NET INCOME PER SHARE—DILUTED:
Dilutive securities	223	196	251	185

Net Income Per Share and Stoc_4

Net Income Per Share and Stockholders' Equity - Narrative (Details) - USD ($) $ in Thousands, shares in Millions	Oct. 01, 2021	Dec. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Apr. 30, 2021
Net Income Per Share And Stockholders Equity [Line Items]
Share repurchases (in shares)			1.5		2.6
Share repurchases			$ (176,622)		$ (292,000)
Stock repurchase program, additional amount authorized					250,000
Stock repurchase program, authorized amount							$ 42,000
Allocation of ESOP shares to participants for compensation			10,085	$ 6,304	22,149	$ 10,340
Redeemable Convertible Preferred Stock
Net Income Per Share And Stockholders Equity [Line Items]
ESOP temporary equity stock distributed during period				(6,657)	(12,412)	(6,657)
Paid-In Capital
Net Income Per Share And Stockholders Equity [Line Items]
Allocation of ESOP shares to participants for compensation			$ 10,085	$ 6,304	$ 22,149	$ 10,340
Subsequent Event
Net Income Per Share And Stockholders Equity [Line Items]
Allocation of ESOP shares to participants for compensation (in shares)	1.1
Subsequent Event | Redeemable Convertible Preferred Stock | Scenario Forecast
Net Income Per Share And Stockholders Equity [Line Items]
ESOP temporary equity stock distributed during period		$ 17,600
Subsequent Event | Paid-In Capital | Scenario Forecast
Net Income Per Share And Stockholders Equity [Line Items]
Allocation of ESOP shares to participants for compensation		$ 17,600

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	6 Months Ended
	Sep. 30, 2021	Mar. 31, 2021
Related Party Transaction [Line Items]
Outstanding principal balance including letters of credit	$ 5,500,000
South American Joint Venture
Related Party Transaction [Line Items]
Maximum borrowings permitted under credit facility	$ 22,000,000
Company's ownership percentage	50.00%
Percentage of debt guarantee	50.00%
Maximum potential payment under guarantee	$ 11,000,000
Outstanding principal balance including letters of credit	8,900,000	$ 10,000,000
South American Joint Venture | US Dollar Denominated Loans
Related Party Transaction [Line Items]
Outstanding principal balance including letters of credit	$ 0
South American Joint Venture | Chilean Peso Denominated Loans
Related Party Transaction [Line Items]
Weighted average interest rate	4.40%
Consolidated Entity Excluding Variable Interest Entities (VIE)
Related Party Transaction [Line Items]
Revolving credit facility maturity date	Jun. 22, 2018
Maximum borrowings permitted under credit facility	$ 12,000,000
Debt, expiration date	Jun. 22, 2022
Maximum borrowings permitted under credit facility	$ 0	$ 0
ADS Mexicana | Consolidated Entity Excluding Variable Interest Entities (VIE)
Related Party Transaction [Line Items]
Percentage of ownership in joint venture	49.00%
Consolidated Entity Excluding Variable Interest Entities (VIE) | ADS Mexicana
Related Party Transaction [Line Items]
Company's ownership percentage	51.00%

Debt - Long-Term Debt (Detail)

Debt - Long-Term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
Debt Instrument [Line Items]
Long-term debt , Gross	$ 910,350	$ 791,250
Unamortized debt issuance costs	(1,839)	(2,030)
Current maturities	(7,000)	(7,000)
Long-term debt obligation	901,511	782,220
Term Loan Facility
Debt Instrument [Line Items]
Long-term debt , Gross	437,750	441,250
Senior Notes
Debt Instrument [Line Items]
Long-term debt , Gross	350,000	350,000
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt , Gross	$ 122,600	$ 0

Debt (Senior Secured Credit Fac

Debt (Senior Secured Credit Facility) - Additional Information (Detail) - USD ($)	6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2021	Sep. 30, 2019
Debt Instrument [Line Items]
Repayment of borrowings	$ 24,200,000	$ 100,000,000
Proceeds from Revolving Credit Agreement	146,800,000	$ 0
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowings permitted under credit facility				$ 350,000,000
Repayment of borrowings	24,200,000
Outstanding letters of credit	12,500,000		$ 11,000,000
Proceeds from Revolving Credit Agreement	146,800,000
Letter of Credit Facility
Debt Instrument [Line Items]
Maximum borrowings permitted under credit facility				50,000,000
Sublimit of Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowings permitted under credit facility				50,000,000
Term Loan Facility
Debt Instrument [Line Items]
Aggregate principal amount				$ 700,000,000
Repayment of borrowings	$ 3,500,000

Debt (Senior Notes) - Additiona

Debt (Senior Notes) - Additional Information (Detail) - 5.0% Senior Notes due 2027 $ in Millions	Sep. 23, 2019USD ($)
Debt Instrument [Line Items]
Aggregate principal amount	$ 350
Debt instrument, interest rate	5.00%

Commitments and Contingencies (

Commitments and Contingencies (Purchase Commitments) - Additional Information (Detail) - Inventory	6 Months Ended
	Sep. 30, 2021USD ($)
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Purchase contracts period range, start	1 month
Purchase contracts period range, end	12 months
Total purchase commitment	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate	26.10%	28.30%	25.80%	28.10%

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	$ 5,618	$ 5,496	$ 12,269	$ 11,095
Non-Employee Director
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	465	332	816	649
Equity-Classified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	860	750	1,613	1,631
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	1,520	1,344	2,879	2,761
Performance Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	2,773	3,070	6,961	6,054
Cost of Goods Sold
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	685	565	1,319	966
Selling Expenses
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Additional stock-based compensation expense	$ 4,933	$ 4,931	$ 10,950	$ 10,129

Stock-Based Compensation (2017

Stock-Based Compensation (2017 Omnibus Plan) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	May 24, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards	$ 0	$ (6)	$ (3,230)	$ (397)
2017 Omnibus Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards (in shares) (less than)	100,000		100,000
Restricted stock awards	$ 2,000		$ 7,300
2017 Omnibus Plan | Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of performance units granted, value			$ 5,300
2017 Omnibus Plan | Performance Shares | IWT
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of performance units granted			100,000
2017 Omnibus Plan | Exercise of Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of stock options granted (in shares)			100,000
Number of stock options granted, value			$ 4,200
2017 Omnibus Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock approved for issuance					5,000,000

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Assumption Used to Estimate Fair Value of Stock Options (Detail)	6 Months Ended
	Sep. 30, 2021$ / shares
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Expected stock price volatility, minimum	41.00%
Risk-free interest rate	1.10%
Weighted-average expected option life (years)	6 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Common stock price	$ 105.82
Dividend yield	0.30%

Business Segments Information -

Business Segments Information - Additional Information (Detail)	6 Months Ended
	Sep. 30, 2021segment
Segment Reporting [Abstract]
Number of reportable segments	3

Business Segments Information_2

Business Segments Information - Schedule of Revenue from Reportable Segments by Product Type (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Net Sales	$ 706,471	$ 544,187	$ 1,375,771	$ 1,052,826
Operating Segments
Segment Reporting Information [Line Items]
Net Sales	(33,254)	(21,225)	(57,108)	(41,138)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	(33,254)	(21,225)	(57,108)	(41,138)
Pipe
Segment Reporting Information [Line Items]
Net Sales	381,853	290,496	753,960	562,303
Pipe | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	384,521	292,133	758,531	565,785
Pipe | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	(2,668)	(1,637)	(4,571)	(3,482)
Infiltrator
Segment Reporting Information [Line Items]
Net Sales	123,499	87,294	231,204	171,379
Infiltrator | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	145,911	105,986	272,653	208,139
Infiltrator | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	(22,412)	(18,692)	(41,449)	(36,760)
International
Segment Reporting Information [Line Items]
Net Sales	58,404	48,402	120,856	84,231
International | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	63,574	49,298	128,940	85,127
International | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	(5,170)	(896)	(8,084)	(896)
International | International - Pipe
Segment Reporting Information [Line Items]
Net Sales	44,971	34,696	92,895	61,646
International | International - Pipe | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	50,141	35,592	100,979	62,542
International | International - Pipe | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	(5,170)	(896)	(8,084)	(896)
International | International - Allied Products & Other
Segment Reporting Information [Line Items]
Net Sales	13,433	13,706	27,961	22,585
International | International - Allied Products & Other | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	13,433	13,706	27,961	22,585
Allied Products & Other
Segment Reporting Information [Line Items]
Net Sales	142,715	117,995	269,751	234,913
Allied Products & Other | Operating Segments
Segment Reporting Information [Line Items]
Net Sales	145,719	117,995	272,755	234,913
Allied Products & Other | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Sales	$ (3,004)	$ 0	$ (3,004)	$ 0

Business Segments Information_3

Business Segments Information - Schedule of Financial Information Attributable to Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Segment adjusted gross profit	$ 225,854	$ 228,935	$ 454,062	$ 438,980
Depreciation and amortization	34,194	35,778	68,850	71,559
Capital expenditures	38,218	18,664	63,764	28,959
Net sales	706,471	544,187	1,375,771	1,052,826
Pipe
Segment Reporting Information [Line Items]
Net sales	381,853	290,496	753,960	562,303
Infiltrator
Segment Reporting Information [Line Items]
Net sales	123,499	87,294	231,204	171,379
International
Segment Reporting Information [Line Items]
Net sales	58,404	48,402	120,856	84,231
Allied Products & Other
Segment Reporting Information [Line Items]
Net sales	142,715	117,995	269,751	234,913
Operating Segments
Segment Reporting Information [Line Items]
Net sales	(33,254)	(21,225)	(57,108)	(41,138)
Operating Segments | Pipe
Segment Reporting Information [Line Items]
Segment adjusted gross profit	82,472	100,496	166,615	191,095
Depreciation and amortization	12,026	11,543	24,061	22,903
Capital expenditures	12,809	3,911	22,639	8,142
Net sales	384,521	292,133	758,531	565,785
Operating Segments | Infiltrator
Segment Reporting Information [Line Items]
Segment adjusted gross profit	58,847	53,105	118,249	101,033
Depreciation and amortization	3,375	3,005	6,811	6,138
Capital expenditures	22,134	13,781	35,160	17,979
Net sales	145,911	105,986	272,653	208,139
Operating Segments | International
Segment Reporting Information [Line Items]
Segment adjusted gross profit	15,077	14,582	36,455	25,990
Depreciation and amortization	1,290	1,302	2,748	2,600
Capital expenditures	1,264	297	1,514	747
Net sales	63,574	49,298	128,940	85,127
Operating Segments | Allied Products & Other
Segment Reporting Information [Line Items]
Segment adjusted gross profit	67,979	60,380	131,278	120,848
Depreciation and amortization	17,503	19,928	35,230	39,918
Capital expenditures	2,011	675	4,451	2,091
Net sales	145,719	117,995	272,755	234,913
Intersegment Eliminations
Segment Reporting Information [Line Items]
Segment adjusted gross profit	1,479	372	1,465	14
Net sales	(33,254)	(21,225)	(57,108)	(41,138)
Intersegment Eliminations | Pipe
Segment Reporting Information [Line Items]
Net sales	(2,668)	(1,637)	(4,571)	(3,482)
Intersegment Eliminations | Infiltrator
Segment Reporting Information [Line Items]
Net sales	(22,412)	(18,692)	(41,449)	(36,760)
Intersegment Eliminations | International
Segment Reporting Information [Line Items]
Net sales	(5,170)	(896)	(8,084)	(896)
Intersegment Eliminations | Allied Products & Other
Segment Reporting Information [Line Items]
Net sales	$ (3,004)	$ 0	$ (3,004)	$ 0

Business Segments Information_4

Business Segments Information - Reconciliation of Gross Profit to Segment Adjusted Gross Profit (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	$ 200,057	$ 205,857	$ 401,178	$ 394,360
Depreciation and amortization	17,250	16,463	34,782	32,886
ESOP and stock-based compensation expense	8,547	6,598	18,102	11,537
COVID-19 related costs	0	17	0	197
Total Segment Adjusted Gross Profit	$ 225,854	$ 228,935	$ 454,062	$ 438,980

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - $ / shares	1 Months Ended	3 Months Ended		6 Months Ended
	Nov. 04, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared		$ 0.11	$ 0.09	$ 0.22	$ 0.18
Subsequent Event
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.11
Dividend payable date	Dec. 15, 2021
Dividend payable, date of record	Dec. 1, 2021