Advanced Drainage Systems (WMS) 10-Q 4 Feb 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Dec. 31, 2020	Jan. 29, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Registrant Name	ADVANCED DRAINAGE SYSTEMS, INC.
Entity Central Index Key	0001604028
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		70,877,367
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity File Number	001-36557
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
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Title of each class	Common Stock, $0.01 par value per share
Trading Symbol(s)	WMS
Name of each exchange on which registered	NYSE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Current assets:
Cash	$ 223,996	$ 174,233
Receivables (less allowance for doubtful accounts of $6,206 and $5,035, respectively)	188,744	200,028
Inventories	238,860	282,398
Other current assets	11,934	9,552
Total current assets	663,534	666,211
Property, plant and equipment, net	496,052	481,380
Other assets:
Goodwill	598,957	597,819
Intangible assets, net	501,812	555,338
Other assets	82,081	69,140
Total assets	2,342,436	2,369,888
Current liabilities:
Current maturities of debt obligations	7,000	7,955
Current maturities of finance lease obligations	18,957	20,382
Accounts payable	108,368	106,710
Other accrued liabilities	119,956	101,116
Accrued income taxes	23,278	2,050
Total current liabilities	277,559	238,213
Long-term debt obligations (less unamortized debt issuance costs of $2,126 and $2,419, respectively)	783,874	1,089,368
Long-term finance lease obligations	34,007	44,501
Deferred tax liabilities	167,645	175,616
Other liabilities	52,453	37,608
Total liabilities	1,315,538	1,585,306
Commitments and contingencies (see Note 12)
Mezzanine equity:
Redeemable convertible preferred stock: $0.01 par value; 47,070 shares authorized; 44,170 shares issued; 20,439 and 21,562 shares outstanding, respectively	255,491	269,529
Deferred compensation – unearned ESOP shares	(13,952)	(22,432)
Total mezzanine equity	241,539	247,097
Stockholders’ equity:
Common stock; $0.01 par value: 1,000,000 shares authorized; 70,989 and 69,810 shares issued, respectively; 70,488 and 69,319 shares outstanding, respectively	11,567	11,555
Paid-in capital	882,843	827,573
Common stock in treasury, at cost	(10,949)	(10,461)
Accumulated other comprehensive loss	(24,353)	(35,325)
Retained deficit	(86,903)	(267,619)
Total ADS stockholders’ equity	772,205	525,723
Noncontrolling interest in subsidiaries	13,154	11,762
Total stockholders’ equity	785,359	537,485
Total liabilities, mezzanine equity and stockholders’ equity	$ 2,342,436	$ 2,369,888

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Allowance for doubtful accounts	$ 6,206	$ 5,035
Unamortized debt issuance costs	$ 2,126	$ 2,419
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	70,989,000	69,810,000
Common stock, shares outstanding	70,488,000	69,319,000
Redeemable Convertible Preferred Stock [Member]
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	20,439,000	21,562,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Net sales	$ 486,145	$ 393,424	$ 1,538,971	$ 1,303,037
Cost of goods sold	317,640	270,066	976,106	926,703
Cost of goods sold - ESOP special dividend compensation				168,610
Gross profit	168,505	123,358	562,865	207,724
Operating expenses:
Selling	30,537	29,967	89,283	86,303
General and administrative	36,069	37,023	104,800	116,486
Loss on disposal of assets and costs from exit and disposal activities	980	1,755	3,254	4,466
Intangible amortization	17,956	13,593	53,893	24,435
Income (loss) from operations	82,963	41,020	311,635	(102,108)
Other expense:
Interest expense	8,433	13,191	27,763	70,787
Derivative (loss) gains and other (expense) income, net	(165)	39	(883)	118
Income (loss) before income taxes	74,695	27,790	284,755	(173,013)
Income tax expense	20,264	4,032	79,291	22,855
Equity in net loss (income) of unconsolidated affiliates	390	99	150	(538)
Net income (loss)	54,041	23,659	205,314	(195,330)
Less: net income attributable to noncontrolling interest	267	371	838	149
Net income (loss) attributable to ADS	$ 53,774	$ 23,288	$ 204,476	$ (195,479)
Weighted average common shares outstanding:
Basic	70,450	68,508	69,893	62,119
Diluted	71,586	69,298	70,853	62,119
Net income (loss) per share:
Basic	$ 0.63	$ 0.28	$ 2.42	$ (3.31)
Diluted	$ 0.62	$ 0.28	$ 2.38	$ (3.31)
ESOP special dividend compensation [Member]
Operating expenses:
Selling, general and administrative - ESOP special dividend compensation				$ 78,142

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 54,041	$ 23,659	$ 205,314	$ (195,330)
Currency translation gain	7,440	2,062	12,996	1,316
Comprehensive income (loss)	61,481	25,721	218,310	(194,014)
Less: other comprehensive income attributable to noncontrolling interest	1,367	604	2,024	418
Less: net income attributable to noncontrolling interest	267	371	838	149
Total comprehensive income (loss) attributable to ADS	$ 59,847	$ 24,746	$ 215,448	$ (194,581)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities
Net income (loss)	$ 205,314	$ (195,330)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	107,321	74,432
Deferred income taxes	(8,032)	(1,098)
Loss on disposal of assets and costs from exit and disposal activities	3,254	4,466
ESOP and stock-based compensation	45,413	27,365
ESOP special dividend compensation		246,752
Amortization of deferred financing charges	293	34,380
Inventory step up related to Infiltrator Water Technologies acquisition		7,880
Fair market value adjustments to derivatives	(2,537)	903
Equity in net income (loss) of unconsolidated affiliates	150	(538)
Other operating activities	6,162	(6,013)
Changes in working capital:
Receivables	12,502	50,865
Inventories	46,809	43,317
Prepaid expenses and other current assets	(2,288)	(1,417)
Accounts payable, accrued expenses, and other liabilities	34,415	10,354
Net cash provided by operating activities	448,776	296,318
Cash Flows from Investing Activities
Capital expenditures	(57,675)	(46,293)
Acquisition of Infiltrator Water Technologies, net of cash acquired		(1,089,322)
Other investing activities	516	(247)
Net cash used in investing activities	(57,159)	(1,135,862)
Cash Flows from Financing Activities
Proceeds from Term Loan Facility		1,300,000
Payments on Term Loan Facility		(1,300,000)
Proceeds from syndication of Term Loan Facility		700,000
Payments on syndicated Term Loan Facility	(205,250)	(50,000)
Proceeds from Senior Notes		350,000
Proceeds from Credit Agreement		177,900
Payments on Credit Agreement	(100,000)	(177,900)
Debt issuance costs		(34,606)
Payments on Prudential Senior Notes		(100,000)
Payments on finance lease obligations	(15,859)	(18,424)
Proceeds from common stock offering, net of offering costs		293,648
Cash dividends paid	(24,507)	(83,846)
Proceeds from exercise of stock options	3,989	6,280
Other financing activities	(1,489)	(236)
Net cash (used in) provided by financing activities	(343,116)	928,416
Effect of exchange rate changes on cash	1,262	549
Net change in cash	49,763	89,421
Cash at beginning of period	174,233	8,891
Cash at end of period	223,996	98,312
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	64,344	9,450
Cash paid for interest	25,305	23,992
Non-cash operating, investing and financing activities:
Acquisition of property, plant and equipment under finance lease and incurred lease obligations	4,299	3,238
Balance in accounts payable for the acquisition of property, plant and equipment	$ 3,443	4,129
PNC Credit Agreement [Member]
Cash Flows from Financing Activities
Proceeds from Credit Agreement		253,900
Payments on Credit Agreement		$ (388,300)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Paid-In Capital [Member]	Common Stock in Treasury [Member]	Accumulated Other Comprehensive Loss [Member]	Retained (Deficit) Earnings [Member]	Retained (Deficit) Earnings [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Total ADS Stockholders' Equity [Member]	Total ADS Stockholders' Equity [Member]Cumulative Effect, Period of Adoption, Adjustment [Member]	Non-controlling Interest in Subsidiaries [Member]
Beginning Balance, Value at Mar. 31, 2019	$ 398,313		$ 11,436	$ 391,039	$ (9,863)	$ (25,867)	$ 17,582		$ 384,327		$ 13,986
Beginning Balance, Shares at Mar. 31, 2019			57,964		474
Net income (loss)	(195,330)						(195,479)		(195,479)		149
Other comprehensive income	1,316					898			898		418
Redeemable convertible preferred stock dividends	(9,530)						(9,530)		(9,530)
Common stock dividends	(74,559)						(74,559)		(74,559)
Allocation of ESOP shares to participants for compensation	9,199			9,199					9,199
'ESOP special dividend compensation	101,189			101,189					101,189
Exercise of common stock options	6,077		$ 4	6,280	$ (207)				6,077
Exercise of common stock options, Shares			441		7
Restricted stock awards	(129)		$ 1		$ (130)				(129)
Restricted stock awards, Shares			90		4
Stock-based compensation expense	8,884			8,884					8,884
ESOP distribution in common stock	6,742		$ 4	6,738					6,742
ESOP distribution in common stock, Shares			415
Common Stock Offering	293,648		$ 104	293,544					293,648
Common Stock Offering, Shares			10,350
Other	155			155					155
Ending Balance, Value at Dec. 31, 2019	545,975		$ 11,549	817,028	$ (10,200)	(24,969)	(261,986)		531,422		14,553
Ending Balance, Shares at Dec. 31, 2019			69,260		485
Beginning Balance, Value at Sep. 30, 2019	511,756		$ 11,545	800,947	$ (10,162)	(26,427)	(277,725)		498,178		13,578
Beginning Balance, Shares at Sep. 30, 2019			68,746		484
Net income (loss)	23,659						23,288		23,288		371
Other comprehensive income	2,062					1,458			1,458		604
Redeemable convertible preferred stock dividends	(1,335)						(1,335)		(1,335)
Common stock dividends	(6,214)						(6,214)		(6,214)
Allocation of ESOP shares to participants for compensation	4,317			4,317					4,317
Exercise of common stock options	3,852		$ 2	3,850					3,852
Exercise of common stock options, Shares			273
Restricted stock awards	(38)				$ (38)				(38)
Restricted stock awards, Shares			2		1
Stock-based compensation expense	3,872			3,872					3,872
ESOP distribution in common stock	3,889		$ 2	3,887					3,889
ESOP distribution in common stock, Shares			239
Other	155			155					155
Ending Balance, Value at Dec. 31, 2019	545,975		$ 11,549	817,028	$ (10,200)	(24,969)	(261,986)		531,422		14,553
Ending Balance, Shares at Dec. 31, 2019			69,260		485
Beginning Balance, Value at Mar. 31, 2020	$ 537,485	$ (779)	$ 11,555	827,573	$ (10,461)	(35,325)	(267,619)	$ (779)	525,723	$ (779)	11,762
Beginning Balance, Shares at Mar. 31, 2020			69,810		491
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Net income (loss)	$ 205,314						204,476		204,476		838
Other comprehensive income	12,996					10,972			10,972		2,024
Redeemable convertible preferred stock dividends	(3,983)						(3,983)		(3,983)
Common stock dividends	(18,998)						(18,998)		(18,998)
Dividend paid to noncontrolling interest holder	(1,470)										(1,470)
Allocation of ESOP shares to participants for compensation	21,026			21,026					21,026
Exercise of common stock options	3,991		$ 2	3,989					3,991
Exercise of common stock options, Shares			181
Restricted stock awards	(487)		$ 1		$ (488)				(487)
Restricted stock awards, Shares			134		10
Stock-based compensation expense	15,908			15,908					15,908
ESOP distribution in common stock	14,038		$ 9	14,029					14,038
ESOP distribution in common stock, Shares			864
Other	318			318					318
Ending Balance, Value at Dec. 31, 2020	785,359		$ 11,567	882,843	$ (10,949)	(24,353)	(86,903)		772,205		13,154
Ending Balance, Shares at Dec. 31, 2020			70,989		501
Beginning Balance, Value at Sep. 30, 2020	709,510		$ 11,562	859,254	$ (10,859)	(30,426)	(133,011)		696,520		12,990
Beginning Balance, Shares at Sep. 30, 2020			70,502		500
Net income (loss)	54,041						53,774		53,774		267
Other comprehensive income	7,440					6,073			6,073		1,367
Redeemable convertible preferred stock dividends	(1,288)						(1,288)		(1,288)
Common stock dividends	(6,378)						(6,378)		(6,378)
Dividend paid to noncontrolling interest holder	(1,470)										(1,470)
Allocation of ESOP shares to participants for compensation	10,686			10,686					10,686
Exercise of common stock options	714			714					714
Exercise of common stock options, Shares			29
Restricted stock awards	(90)				$ (90)				(90)
Restricted stock awards, Shares			4		1
Stock-based compensation expense	4,813			4,813					4,813
ESOP distribution in common stock	7,381		$ 5	7,376					7,381
ESOP distribution in common stock, Shares			454
Ending Balance, Value at Dec. 31, 2020	$ 785,359		$ 11,567	$ 882,843	$ (10,949)	$ (24,353)	$ (86,903)		$ 772,205		$ 13,154
Ending Balance, Shares at Dec. 31, 2020			70,989		501

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Mezzanine Equity - USD ($) shares in Thousands, $ in Thousands	Total	Redeemable Convertible Preferred Stock [Member]	Deferred Compensation - Unearned ESOP Shares [Member]	Total Mezzanine Equity [Member]
Beginning Balance, Value at Mar. 31, 2019		$ 282,638	$ (180,316)	$ 102,322
Beginning Balance, Shares at Mar. 31, 2019		22,611	14,452
Other comprehensive income	$ 1,316
Redeemable convertible preferred stock dividends	(9,530)
Common stock dividends	(74,559)
Allocation of ESOP shares to participants for compensation	9,199		$ 9,282	9,282
Allocation of ESOP shares to participants for Compensation, Shares			(743)
'ESOP special dividend compensation			$ 145,563	145,563
ESOP special dividend compensation, Shares			(11,645)
Exercise of common stock options	6,077
Restricted stock awards	(129)
Stock-based compensation expense	8,884
ESOP distribution in common stock		$ (6,742)		(6,742)
ESOP distribution in common stock, Shares		(539)
Other	155
Ending Balance, Value at Dec. 31, 2019		$ 275,896	$ (25,471)	250,425
Ending Balance, Shares at Dec. 31, 2019		22,072	2,064
Beginning Balance, Value at Sep. 30, 2019		$ 279,785	$ (28,565)	251,220
Beginning Balance, Shares at Sep. 30, 2019		22,383	2,312
Other comprehensive income	2,062
Redeemable convertible preferred stock dividends	(1,335)
Common stock dividends	(6,214)
Allocation of ESOP shares to participants for compensation	4,317		$ 3,094	3,094
Allocation of ESOP shares to participants for Compensation, Shares			(248)
Exercise of common stock options	3,852
Restricted stock awards	(38)
Stock-based compensation expense	3,872
ESOP distribution in common stock		$ (3,889)		(3,889)
ESOP distribution in common stock, Shares		(311)
Other	155
Ending Balance, Value at Dec. 31, 2019		$ 275,896	$ (25,471)	250,425
Ending Balance, Shares at Dec. 31, 2019		22,072	2,064
Retained deficit	(267,619)
Beginning Balance, Value at Mar. 31, 2020	247,097	$ 269,529	$ (22,432)	247,097
Beginning Balance, Shares at Mar. 31, 2020		21,562	1,850
Other comprehensive income	12,996
Redeemable convertible preferred stock dividends	(3,983)
Common stock dividends	(18,998)
Dividend paid to noncontrolling interest holder	(1,470)
Allocation of ESOP shares to participants for compensation	21,026		$ 8,480	8,480
Allocation of ESOP shares to participants for Compensation, Shares			(678)
Exercise of common stock options	3,991
Restricted stock awards	(487)
Stock-based compensation expense	15,908
ESOP distribution in common stock		$ (14,038)		(14,038)
ESOP distribution in common stock, Shares		(1,123)
Other	318
Ending Balance, Value at Dec. 31, 2020	241,539	$ 255,491	$ (13,952)	241,539
Ending Balance, Shares at Dec. 31, 2020		20,439	1,172
Beginning Balance, Value at Sep. 30, 2020		$ 262,872	$ (16,779)	246,093
Beginning Balance, Shares at Sep. 30, 2020		21,030	1,398
Other comprehensive income	7,440
Redeemable convertible preferred stock dividends	(1,288)
Common stock dividends	(6,378)
Dividend paid to noncontrolling interest holder	(1,470)
Allocation of ESOP shares to participants for compensation	10,686		$ 2,827	2,827
Allocation of ESOP shares to participants for Compensation, Shares			(226)
Exercise of common stock options	714
Restricted stock awards	(90)
Stock-based compensation expense	4,813
ESOP distribution in common stock		$ (7,381)		(7,381)
ESOP distribution in common stock, Shares		(591)
Ending Balance, Value at Dec. 31, 2020	241,539	$ 255,491	$ (13,952)	$ 241,539
Ending Balance, Shares at Dec. 31, 2020		20,439	1,172
Retained deficit	$ (86,903)

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Statement Of Stockholders Equity [Abstract]
Common stock dividends per share	$ 0.09	$ 0.09	$ 0.27	$ 1.27

Background and Summary of Signi

Background and Summary of Significant Accounting Policies	9 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Background and Summary of Significant Accounting Policies	1. 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. On July 31, 2019, the Company completed the Acquisition of Infiltrator Water Technologies. Infiltrator Water Technologies is a leading national provider of plastic leach field chambers and systems, septic tanks and accessories, primarily for use in residential applications. Infiltrator Water Technologies’ products are used in on-site septic wastewater treatment systems in the United States and Canada. See “Note 3. Acquisitions” for additional information on the Acquisition. The Company is managed and reports results of operations in three reportable segments: Pipe, Infiltrator Water Technologies 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, 2020 was derived from audited financial statements included in the Annual Report on Form 10-K for the year ended March 31, 2020 (“Fiscal 2020 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 December 31, 2020 and the results of operations for the three and nine months ended December 31, 2020 and cash flows for the nine months ended December 31, 2020. 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 2020 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. Recent Accounting Guidance Recently Adopted Accounting Guidance Standard Adoption Accounting Standards Update 2016-13 – Financial Instruments-Credit Losses (ASU 2016-13) In June 2016, the Financial Accounting Standards Board (the “FASB”) issued an Accounting Standards Update (“ASU”) which provides amended guidance on the measurement of credit losses on financial instruments, including trade receivables. This standard requires the use of an impairment model referred to as the current expected credit loss model. The Company adopted this standard effective April 1, 2020 using a modified retrospective approach t hrough a cumulative-effect adjustment to Retained deficit as of the beginning of the first reporting period in which the guidance is effective Accounting Policy - The Company extends credit to customers based on an evaluation of their financial condition and collateral is generally not required. The Company records an allowance for credit losses at the time accounts receivable are recorded based on the Company’s historical write-off activity, an evaluation of the current economic environment and the Company’s expectations of future economic conditions. Recent Accounting Guidance Not Yet Adopted Standard Description Effective Date Effect on financial statements or other significant matters ASU 2020-06, FASB Simplifies Issuer’s Accounting for Convertible Instruments and Contracts on an Entity’s Own Equity In August 2020, the FASB issued an ASU which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. The amendments are effective after December 15, 2023 and an entity may elect to early adopt beginning after December 15, 2020. The Company is currently evaluating the impact of this standard on the Consolidated Financial Statements. ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Statements In March 2020, the FASB issued an ASU that provides optional expedients and exceptions related to financial reporting impacts related to the expected market transition from LIBOR to another reference rates. The amendments are effective on March 12, 2020, and an entity may elect to adopt prospectively through December 31, 2022. The Company is currently evaluating the impact of this standard on the Consolidated Financial Statements. 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 The amendments in this ASU are effective for fiscal years beginning after December 15, 2020, and early adoption is permitted. The Company is currently evaluating the impact of this standard on the Consolidated Financial Statements. Except for the pronouncements described above, there have been no new accounting pronouncements issued or adopted since the filing of the Fiscal 2020 Form 10-K that have significance, or potential significance, to the Condensed Consolidated Financial Statements.

Loss on Disposal of Assets and

Loss on Disposal of Assets and Costs from Exit and Disposal Activities	9 Months Ended
	Dec. 31, 2020
Discontinued Operations And Disposal Groups [Abstract]
Loss on Disposal of Assets and Costs from Exit and Disposal Activities	2. In fiscal 2021, the Company undertook certain restructuring activities (the “2021 Restructuring Plan”), which followed the Company’s initiation of a restructuring plan in fiscal 2018 (the “2018 Restructuring Plan”). Actions taken under the 2021 Restructuring Plan included reducing headcount and eliminating nonessential costs designed to improve the Company’s cost structure. The Company does not currently have an estimate of additional costs or an expected end date for the restructuring actions. The following table summarizes the activity included in Loss on disposal of assets and costs from exit and disposal activities recorded during the periods presented. Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Headcount reduction $ 300 $ — $ 1,901 $ — Total 2021 Restructuring Plan activities $ 300 $ — $ 1,901 $ — Loss on other disposals and partial disposals of property, plant and equipment 680 894 1,353 2,045 Acquisition related severance and other costs — 861 — 2,421 Total loss on disposal of assets and costs from exit and disposal activities $ 980 $ 1,755 $ 3,254 $ 4,466 The restructuring activities are classified as operating expenses and not allocated to a segment. A reconciliation of the beginning and ending amounts of restructuring liability related to the 2021 and 2018 Restructuring Plans as of the December 31, 2020 and 2019 is as follows: Nine Months Ended December 31, 2020 2019 (In thousands) Balance at the beginning of the period $ 574 $ 1,696 Expenses 1,901 — Payments (1,501 ) (1,008 ) Balance at the end of the period $ 974 $ 688 As of December 31, 2020, the Company had $0.1 million of long-term severance liability related to the restructuring activities recorded in other liabilities in the Condensed Consolidated Balance Sheet. The current portion of the restructuring liability is recorded in Other accrued liabilities in the Condensed Consolidated Balance Sheet.

Acquisitions

Acquisitions	9 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions	3. ACQUISITIONS Acquisition of Infiltrator Water Technologies - On July 31, 2019 (the “Closing Date”), the Company completed its Acquisition of Infiltrator Water Technologies pursuant to an Agreement and Plan of Merger (the “Merger Agreement”) dated July 31, 2019. Infiltrator Water Technologies manufactures and sells wastewater systems for homes and provides drainage chambers for septic and storm water management. The total fair value of consideration transferred was $1,147.2 million. The following table summarizes the consideration transferred and the purchase price allocation of the assets acquired and liabilities assumed. The Company finalized the valuations of assets acquired and liabilities assumed during the second quarter of fiscal 2021. (Amounts in thousands) Initial Amount Adjustments to Purchase Price Adjustments to Property, Plant and Equipment Adjustments to Right-of-use Assets Adjustments to Intangible Assets Tax Adjustments Updated Amount Cash $ 57,375 $ — $ — $ — $ — $ — $ 57,375 Total current asset, excluding cash 75,847 — — — — — 75,847 Property, plant and equipment, net 98,860 — (6,575 ) — — — 92,285 Goodwill 567,034 704 6,575 — (100,000 ) 21,528 495,841 Intangible assets, net 475,000 — — — 100,000 — 575,000 Other assets 14,366 — — 2,909 — — 17,275 Total current liabilities (22,756 ) — — (213 ) — 931 (22,038 ) Deferred tax liabilities (109,926 ) — — — — (22,459 ) (132,385 ) Other liabilities (9,274 ) — — (2,696 ) — — (11,970 ) Total fair value of consideration transferred $ 1,146,526 $ 704 $ — $ — $ — $ — $ 1,147,230 The fair value of consideration transferred includes $6.0 million of Infiltrator Water Technologies payable to the Company and $6.6 million of Infiltrator Water Technologies receivable due from the Company. The goodwill of $495.8 million represents the excess of consideration transferred over the fair value of assets acquired and liabilities assumed and is attributable to expected revenue synergies, as well as operating efficiencies and cost savings. The goodwill is not deductible for tax purposes and is assigned to the Infiltrator Water Technologies segment. Of the $132.4 million of the purchase price allocated to deferred tax liabilities, $82.3 million related to the step up of GAAP basis for fair market valuations, while the remaining $50.1 million were acquired deferred tax liabilities. Of the total $82.3 million, $80.2 million was attributed to intangible assets. See “Note 13. Income Taxes” for additional information. The purchase price excludes transaction costs. During the fiscal year ended March 31, 2020, the Company incurred $22.9 million of transaction costs related to the Acquisition such as legal, accounting, valuation and other professional services. The Company did not incur any transaction costs during the three and nine months ended December 31, 2020. For tax purposes, $7.1 million of transaction costs are not deductible. These costs are included in general and administrative expenses in the Condensed Consolidated Statements of Operations and Condensed Consolidated Statements of Comprehensive Income. The identifiable intangible assets recorded in connection with the closing of the Acquisition are based on valuations including customer relationships, patents and developed technology, and tradename and trademarks totaling $575.0 million. Customer relationships are amortized using an accelerated method over an estimated useful life of 20 years. Patents and developed technology and tradename and trademarks are on a straight-line basis over the respective useful lives of 10 and 20 years. (Amounts in thousands) Fair value Estimated useful lives Customer relationships $ 360,000 20 years Patents and developed technology 150,000 10 years Tradename and trademarks 65,000 20 years Total identifiable intangible assets $ 575,000 The unaudited pro forma information for the three and nine months ended December 31, 2019 presented below includes the effects of the Acquisition as if it had been consummated as of April 1, 2018, with adjustments to give effect to pro forma events that are directly attributable to the Acquisition. include those related to the amortization of acquired intangible assets, increases in interest expense due to additional borrowings incurred to finance the Acquisition, transaction costs, the elimination of transactions between the Company and Infiltrator Water Technologies and the estimated tax impacts thereof. The unaudited pro forma information does not reflect any operating efficiency or potential cost savings that could result from the consolidation of Infiltrator Water Technologies. Accordingly, the unaudited pro forma information is presented for informational purposes only and is not necessarily indicative of the actual results of the combined company if the Acquisition had occurred at the beginning of the period presented, nor is it indicative of the future results of operations. Three Months Ended Nine Months Ended (Amounts in thousands) December 31, 2019 December 31, 2019 Net sales $ 393,424 $ 1,389,440 Net income (loss) attributable to ADS 24,630 (146,147 )

Revenue Recognition

Revenue Recognition	9 Months Ended
	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Revenue Recognition	4 . REVENUE RECOGNITION Revenue Disaggregation - The Company disaggregates net sales by Domestic, International and Infiltrator Water Technologies 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 15. 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: December 31, 2020 March 31, 2020 (In thousands) Contract asset - product returns $ 874 $ 594 Refund liability 2,340 1,458

Leases

Leases	9 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	5 . 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. The Company’s lease payments are generally fixed. Certain equipment leases contain residual value guarantees that create a contingent obligation on the part of the Company to compensate the lessor if the leased asset cannot be sold for an amount in excess of a specified minimum value at the conclusion of the lease term. The calculation is based on the original cost of the transportation equipment, less lease payments made, compared to a percentage of the transportation equipment’s fair market value at the time of sale. All leased units covered by this guarantee have been classified as finance leases and a corresponding finance lease obligation was recorded. Therefore, no contingent obligation is needed. The Company records at the lease commencement date , a lease liability, which is the lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The Company will utilize its collateralized incremental borrowing rate commensurate to the lease term as the discount rate for its leases , unless the Company can specifically determine the lessor’s implicit rate. The incremental borrowing rate for each lease is determined based on the Company’s credit rating, adjusted for the impacts of collateral , and the lease term .

Inventories

Inventories	9 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	6 . Inventories as of the periods presented consisted of the following: December 31, 2020 March 31, 2020 (In thousands) Raw materials $ 63,569 $ 66,524 Finished goods 175,291 215,874 Total inventories $ 238,860 $ 282,398 There were no work-in-process inventories as of the periods presented.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurement	7 . 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: December 31, 2020 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 535 $ — $ 535 $ — Total assets at fair value on a recurring basis $ 535 $ — $ 535 $ — Liabilities: Derivative liabilities – diesel fuel contracts $ 188 $ — $ 188 $ — Total liabilities at fair value on a recurring basis $ 188 $ — $ 188 $ — March 31, 2020 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 36 $ — $ 36 $ — Total assets at fair value on a recurring basis $ 36 $ — $ 36 $ — Liabilities: Derivative liabilities - diesel fuel contracts $ 2,228 $ — $ 2,228 $ — Total liabilities at fair value on a recurring basis $ 2,228 $ — $ 2,228 $ — For the nine months ended December 31, 2020 and 2019, there were no transfers in or out of Levels 1, 2 or 3. 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 11. Debt”) for the periods presented: December 31, 2020 March 31, 2020 Fair Value Carrying Value Fair Value Carrying Value (In thousands) (In thousands) Senior Notes $ 370,010 $ 350,000 $ 314,951 $ 350,000

Derivative Transactions

Derivative Transactions	9 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Derivative Transactions	8 . 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. Interest rate swap gains and losses resulting from the difference between the spot rate and applicable base rate is recorded in the Condensed Consolidated Statements of Operations in Interest expense. 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 and other income, net. Gains and losses related to mark-to-market adjustments for changes in fair value of the derivative contracts are also recorded in the Condensed Consolidated Statements of Operations in Derivative gains and other income, net. 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 December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Diesel fuel option collars $ (1,082 ) $ (93 ) $ (2,537 ) $ (17 ) Interest rate swaps — — — 1,726 Foreign exchange forward contracts — — — (7 ) Total net unrealized mark-to-market (gains) loss $ (1,082 ) $ (93 ) $ (2,537 ) $ 1,702 Diesel fuel option collars 261 — 1,578 157 Foreign exchange forward contracts — — — 102 Interest rate swaps — — — 544 Total net realized loss $ 261 $ — $ 1,578 $ 803 A summary of the fair value of derivatives is included in “Note 7. Fair Value Measurement.”

Net Income Per Share and Stockh

Net Income Per Share and Stockholders' Equity	9 Months Ended
	Dec. 31, 2020
Net Income Per Share And Stockholders Equity [Abstract]
Net Income Per Share and Stockholders' Equity	9 . 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 December 31, Nine Months Ended December 31, (In thousands, except per share data) 2020 2019 2020 2019 NET INCOME PER SHARE—BASIC: Net income (loss) attributable to ADS $ 53,774 $ 23,288 $ 204,476 $ (195,479 ) Adjustments for: Dividends to redeemable convertible preferred stockholders (1,288 ) (1,334 ) (3,983 ) (9,530 ) Dividends paid to unvested restricted stockholders — (3 ) (2 ) (335 ) Net income (loss) available to common stockholders and participating securities 52,486 21,951 200,491 (205,344 ) Undistributed income allocated to participating securities (7,798 ) (2,822 ) (31,699 ) — Net income (loss) available to common stockholders – Basic $ 44,688 $ 19,129 $ 168,792 $ (205,344 ) Weighted average number of common shares outstanding – Basic 70,450 68,508 69,893 62,119 Net income (loss) per common share – Basic $ 0.63 $ 0.28 $ 2.42 $ (3.31 ) NET INCOME PER SHARE—DILUTED: Net income (loss) available to common stockholders – Diluted $ 44,688 $ 19,129 $ 168,792 $ (205,344 ) Weighted average number of common shares outstanding – Basic 70,450 68,508 69,893 62,119 Assumed exercise of stock options 886 641 745 — Restricted stock 250 149 215 — Weighted average number of common shares outstanding – Diluted 71,586 69,298 70,853 62,119 Net income (loss) per common share – Diluted $ 0.62 $ 0.28 $ 2.38 $ (3.31 ) Potentially dilutive securities excluded as anti-dilutive 14,347 14,915 14,807 14,084 Special Dividend and the Employees Stock Ownership Plan (“ESOP”) - During the three months ended June 30, 2019, the Board of Directors approved a special cash dividend of $1.00 per share and quarterly dividends of $0.09 per share. The special and quarterly dividend were paid to all stockholders on June 14, 2019 to stockholders of record at the close of business on June 3, 2019. The total dividend payment was $81.6 million. The dividends received by the unallocated redeemable convertible preferred stock held in the ESOP trust was used to pay $12.0 million of the ESOP loan back to the Company resulting in approximately 11.6 million shares of the Company’s redeemable convertible preferred stock being allocated to ESOP participants. The Company recognized $246.8 million in stock-based compensation expense based on the fair value on the date the Board of Directors approved the special dividend. The Board of Director’s approval committed the ESOP to use those proceeds to pay down the ESOP loan. The special dividend compensation expense was recognized in Cost of goods sold - ESOP special dividend compensation and Selling, general and administrative expenses - ESOP special dividend compensation on the Company’s Condensed Consolidated Statements of Operations.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	10 . 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 December 31, 2020 and March 31, 2020, 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. The Company has concluded that it is appropriate to account for this investment using the equity method, whereby the Company’s share of the income or loss of the joint venture is reported in the Condensed Consolidated Statements of Operations under Equity in net loss (income) of unconsolidated affiliates and the Company’s investment in the joint venture is included in Other assets in the Condensed Consolidated Balance Sheets. 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 debt guarantee was renewed in the nine months ended December 31, 2020. The Company’s maximum potential obligation under this guarantee is $11.0 million as of December 31, 2020. The maximum borrowings permitted under the South American Joint Venture’s credit arrangement are $22.0 million. This credit arrangement allows borrowings in either Chilean pesos or US dollars at a fixed interest rate determined at inception of each draw. The guarantee of the South American Joint Venture’s debt expires on December 31, 2023. ADS does not anticipate any required contributions related to the balance of this credit arrangment. As of December 31, 2020 and March 31, 2020, the outstanding principal balances of the credit arrangement including letters of credit were $10.1 million and $9.3 million, respectively. As of December 31, 2020, there were no U.S. dollar denominated loans. The weighted average interest rate as of December 31, 2020 was 3.5% on Chilean peso denominated loans. ADS and the South American Joint Venture have shared services arrangements in order to execute the joint venture services. In addition, the South American Joint Venture has entered into agreements for pipe and other product sales to ADS and its other related parties. ADS also sells pipe products to the South American Joint Venture. Tigre USA - Tigre USA was a joint venture that ADS no longer has an ownership interest in, but the owner is the partner for the South American Joint Venture. ADS purchases Tigre USA manufactured products for use in the production of ADS products. The following tables summarizes the purchases by ADS from related parties and sales by ADS to related parties for the periods presented: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Purchases from South American Joint Venture $ 212 $ 76 $ 480 $ 584 Sales to South American Joint Venture 134 373 413 767 Purchases from Tigre USA 499 440 1,534 1,611

Debt

Debt	9 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	1 1 . Long-term debt as of the periods presented consisted of the following: December 31, 2020 March 31, 2020 (In thousands) Term Loan Facility $ 443,000 $ 648,250 Senior Notes 350,000 350,000 Revolving Credit Facility — 100,000 Equipment financing — 1,492 Total 793,000 1,099,742 Unamortized debt issuance costs (2,126 ) (2,419 ) Current maturities (7,000 ) (7,955 ) Long-term debt obligation $ 783,874 $ 1,089,368 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 nine months ended December 31, 2020, the Company repaid $205.3 million of the Term Loan Facility and repaid $100.0 million of the Revolving Credit Facility. Letters of credit outstanding at December 31, 2020 and March 31, 2020 amount to $11.0 million and $8.5 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	9 Months Ended
	Dec. 31, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 2 . 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 December 31, 2020. 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. Other Commitments and Contingencies – In March 2019, the Company initiated an internal investigation process, under the guidelines of the Company’s Code of Business Conduct and Ethics, into its consolidated joint venture affiliate ADS Mexicana’s senior management’s ethical and business conduct, as well as compliance of certain products with, along with considerations into, Mexican laws and regulations over the previous 12 months. The Company has recorded an accrual for the current estimate of probable losses resulting from the investigation, which is not material to the Condensed Consolidated Financial Statements. However, due to the inherent uncertainties in determining the use, installation application and location of ADS Mexicana products sold, along with the consideration of Mexican laws and regulations related to warranty and product liability obligations, the Company is unable to determine the maximum potential future losses that may occur, which could be material to the Condensed Consolidated Financial Statements.

Income Taxes

Income Taxes	9 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	The 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 December 31 27.1 For the nine months ended December 31 27.8 As discussed in “Note 3. Acquisitions”, t

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	1 4 . ADS has several programs for stock-based payments to employees and non-employee members of its Board of Directors, including stock options and restricted stock. Equity-classified restricted stock awards are measured based on the grant-date estimated fair value of each award. The fair value of restricted stock is based on the fair value of the Company’s common stock. Compensation expense is recognized on a straight-line basis over the employee’s requisite service period, which is generally the vesting period of the grant. 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 December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Component of income before income taxes: Cost of goods sold $ 510 $ 319 $ 1,476 $ 620 Selling expenses 265 49 756 284 General and administrative expenses 4,038 3,504 13,676 7,980 Total stock-based compensation expense $ 4,813 $ 3,872 $ 15,908 $ 8,884 The following table summarizes stock-based compensation expense by award type for the periods presented: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Stock-based compensation expense: Equity-classified Stock Options $ 623 $ 701 $ 2,254 $ 1,952 Restricted Stock 1,214 1,075 3,975 2,674 Performance Units 2,622 1,776 8,676 3,349 Non-Employee Directors 354 320 1,003 909 Total stock-based compensation expense $ 4,813 $ 3,872 $ 15,908 $ 8,884 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 3.5 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 nine months ended December 31, 2020, the Company granted 0.1 million shares and 0.1 million shares of restricted stock with a grant date fair value of $0.1 million and $5.8 million, respectively. Performance Units – During the three and nine months ended December 31, 2020, the Company granted 0.1 million shares and 0.1 million shares at a grant date fair value of $0.1 million and $5.3 million, respectively. Options - During the three and nine months ended December 31, 2020, the Company granted less than 0.1 million and 0.3 million nonqualified stock options under the 2017 Incentive Plan. The grant date fair value of the nonqualified stock options was $0.1 million and $3.4 million, respectively. 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: Nine Months Ended December 31, 2020 Common stock price $41.97 - $71.55 Expected stock price volatility 35.5% - 36.3% Risk-free interest rate 0.4% - 0.6% Weighted-average expected option life (years) 6.0 Dividend yield 0.5% - 0.9%

Business Segments Information

Business Segments Information	9 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Business Segments Information	1 5 . The Company operates its business in three distinct reportable segments: “Pipe”, “International” and “Infiltrator Water Technologies.” “Allied Products & Other” represents the Company’s Allied Products and all other business segments. 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 Water Technologies – Infiltrator Water Technologies is a leading national provider of plastic leach field chambers and systems, septic tanks and accessories, primarily for use in residential applications. Infiltrator Water Technologies 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 December 31, 2020 December 31, 2019 Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 254,209 $ (1,311 ) $ 252,898 $ 207,897 $ (342 ) $ 207,555 Infiltrator Water Technologies 98,409 (17,188 ) 81,221 72,083 (13,549 ) 58,534 International International - Pipe 33,729 (2,970 ) 30,759 28,340 — 28,340 International - Allied Products & Other 11,648 — 11,648 10,114 — 10,114 Total International 45,377 (2,970 ) 42,407 38,454 — 38,454 Allied Products & Other 109,619 — 109,619 88,881 — 88,881 Intersegment Eliminations (21,469 ) 21,469 — (13,891 ) 13,891 — Total Consolidated $ 486,145 $ — $ 486,145 $ 393,424 $ — $ 393,424 Nine Months Ended December 31, 2020 December 31, 2019 Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 819,994 $ (4,793 ) $ 815,201 $ 751,483 $ (684 ) $ 750,799 Infiltrator Water Technologies 306,548 (53,948 ) 252,600 136,972 (25,738 ) 111,234 International International - Pipe 96,271 (3,866 ) 92,405 92,242 — 92,242 International - Allied Products & Other 34,233 — 34,233 33,330 — 33,330 Total International 130,504 (3,866 ) 126,638 125,572 — 125,572 Allied Products & Other 344,532 — 344,532 315,432 — 315,432 Intersegment Eliminations (62,607 ) 62,607 — (26,422 ) 26,422 — Total Consolidated $ 1,538,971 $ — $ 1,538,971 $ 1,303,037 $ — $ 1,303,037 The following sets forth certain financial information attributable to the reportable segments for the periods presented: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Segment adjusted gross profit Pipe $ 78,651 $ 61,025 $ 269,746 $ 192,764 Infiltrator Water Technologies 48,518 34,735 149,551 64,879 International 12,986 9,066 38,976 29,134 Allied Products & Other 55,158 42,818 176,006 157,626 Intersegment Eliminations (932 ) (881 ) (918 ) (1,859 ) Total $ 194,381 $ 146,763 $ 633,361 $ 442,544 Depreciation and amortization Pipe $ 11,298 $ 11,522 $ 34,201 $ 34,626 Infiltrator Water Technologies 3,132 2,563 9,270 4,422 International 1,402 1,462 4,002 4,559 Allied Products & Other (a) 19,930 15,625 59,848 30,825 Total $ 35,762 $ 31,172 $ 107,321 $ 74,432 Capital expenditures Pipe $ 4,095 $ 7,790 $ 12,237 $ 24,147 Infiltrator Water Technologies 22,651 12,499 40,630 16,382 International 556 191 1,303 2,068 Allied Products & Other (a) 1,414 191 3,505 3,696 Total $ 28,716 $ 20,671 $ 57,675 $ 46,293 (a) Includes depreciation, amortization and capital expenditures not allocated to a reportable segment. The amortization expense of Infiltrator Water Technologies intangible assets acquired is included in Allied Products & Other. Reconciliation of Gross Profit to Segment Adjusted Gross profit Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Reconciliation of Segment Adjusted Gross Profit: Total Gross Profit $ 168,505 $ 123,358 $ 562,865 $ 207,724 Depreciation and amortization 16,432 16,025 49,318 45,417 ESOP and stock-based compensation expense 9,444 5,273 20,981 12,913 ESOP special dividend compensation — — — 168,610 COVID-19 related costs (a) — — 197 — Inventory step up related to Infiltrator Water Technologies acquisition — 2,107 — 7,880 Total Segment Adjusted Gross Profit $ 194,381 $ 146,763 $ 633,361 $ 442,544 (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	9 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	1 6 . Common Stock Dividend - During the fourth quarter of fiscal 2021, the Company declared a quarterly cash dividend of $0.09 per share of common stock. The dividend is payable on March 15, 2021 to stockholders of record at the close of business on March 1, 2021.

Background and Summary of Sig_2

Background and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	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, 2020 was derived from audited financial statements included in the Annual Report on Form 10-K for the year ended March 31, 2020 (“Fiscal 2020 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 December 31, 2020 and the results of operations for the three and nine months ended December 31, 2020 and cash flows for the nine months ended December 31, 2020. 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 2020 Form 10-K.
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.
Recent Accounting Guidance	Recent Accounting Guidance Recently Adopted Accounting Guidance Standard Adoption Accounting Standards Update 2016-13 – Financial Instruments-Credit Losses (ASU 2016-13) In June 2016, the Financial Accounting Standards Board (the “FASB”) issued an Accounting Standards Update (“ASU”) which provides amended guidance on the measurement of credit losses on financial instruments, including trade receivables. This standard requires the use of an impairment model referred to as the current expected credit loss model. The Company adopted this standard effective April 1, 2020 using a modified retrospective approach t hrough a cumulative-effect adjustment to Retained deficit as of the beginning of the first reporting period in which the guidance is effective Accounting Policy - The Company extends credit to customers based on an evaluation of their financial condition and collateral is generally not required. The Company records an allowance for credit losses at the time accounts receivable are recorded based on the Company’s historical write-off activity, an evaluation of the current economic environment and the Company’s expectations of future economic conditions. Recent Accounting Guidance Not Yet Adopted Standard Description Effective Date Effect on financial statements or other significant matters ASU 2020-06, FASB Simplifies Issuer’s Accounting for Convertible Instruments and Contracts on an Entity’s Own Equity In August 2020, the FASB issued an ASU which simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity. The amendments are effective after December 15, 2023 and an entity may elect to early adopt beginning after December 15, 2020. The Company is currently evaluating the impact of this standard on the Consolidated Financial Statements. ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Statements In March 2020, the FASB issued an ASU that provides optional expedients and exceptions related to financial reporting impacts related to the expected market transition from LIBOR to another reference rates. The amendments are effective on March 12, 2020, and an entity may elect to adopt prospectively through December 31, 2022. The Company is currently evaluating the impact of this standard on the Consolidated Financial Statements. 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 The amendments in this ASU are effective for fiscal years beginning after December 15, 2020, and early adoption is permitted. The Company is currently evaluating the impact of this standard on the Consolidated Financial Statements. Except for the pronouncements described above, there have been no new accounting pronouncements issued or adopted since the filing of the Fiscal 2020 Form 10-K that have significance, or potential significance, to the 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. The Company’s lease payments are generally fixed. Certain equipment leases contain residual value guarantees that create a contingent obligation on the part of the Company to compensate the lessor if the leased asset cannot be sold for an amount in excess of a specified minimum value at the conclusion of the lease term. The calculation is based on the original cost of the transportation equipment, less lease payments made, compared to a percentage of the transportation equipment’s fair market value at the time of sale. All leased units covered by this guarantee have been classified as finance leases and a corresponding finance lease obligation was recorded. Therefore, no contingent obligation is needed. The Company records at the lease commencement date , a lease liability, which is the lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. The Company will utilize its collateralized incremental borrowing rate commensurate to the lease term as the discount rate for its leases , unless the Company can specifically determine the lessor’s implicit rate. The incremental borrowing rate for each lease is determined based on the Company’s credit rating, adjusted for the impacts of collateral , and the lease term .

Loss on Disposal of Assets an_2

Loss on Disposal of Assets and Costs from Exit and Disposal Activities (Tables)	9 Months Ended
	Dec. 31, 2020
Discontinued Operations And Disposal Groups [Abstract]
Summary of Loss on Disposal of Assets and Costs from Exit and Disposal Activities	The following table summarizes the activity included in Loss on disposal of assets and costs from exit and disposal activities recorded during the periods presented. Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Headcount reduction $ 300 $ — $ 1,901 $ — Total 2021 Restructuring Plan activities $ 300 $ — $ 1,901 $ — Loss on other disposals and partial disposals of property, plant and equipment 680 894 1,353 2,045 Acquisition related severance and other costs — 861 — 2,421 Total loss on disposal of assets and costs from exit and disposal activities $ 980 $ 1,755 $ 3,254 $ 4,466
Summary of Reconciliation of Restructuring Liability	A reconciliation of the beginning and ending amounts of restructuring liability related to the 2021 and 2018 Restructuring Plans as of the December 31, 2020 and 2019 is as follows: Nine Months Ended December 31, 2020 2019 (In thousands) Balance at the beginning of the period $ 574 $ 1,696 Expenses 1,901 — Payments (1,501 ) (1,008 ) Balance at the end of the period $ 974 $ 688

Acquisitions (Tables)

Acquisitions (Tables) - IWT [Member]	9 Months Ended
	Dec. 31, 2020
Business Acquisition [Line Items]
Summary of Consideration Transferred and Preliminary Purchase Price Allocation of Assets Acquired and Liabilities Assumed	The following table summarizes the consideration transferred and the purchase price allocation of the assets acquired and liabilities assumed. (Amounts in thousands) Initial Amount Adjustments to Purchase Price Adjustments to Property, Plant and Equipment Adjustments to Right-of-use Assets Adjustments to Intangible Assets Tax Adjustments Updated Amount Cash $ 57,375 $ — $ — $ — $ — $ — $ 57,375 Total current asset, excluding cash 75,847 — — — — — 75,847 Property, plant and equipment, net 98,860 — (6,575 ) — — — 92,285 Goodwill 567,034 704 6,575 — (100,000 ) 21,528 495,841 Intangible assets, net 475,000 — — — 100,000 — 575,000 Other assets 14,366 — — 2,909 — — 17,275 Total current liabilities (22,756 ) — — (213 ) — 931 (22,038 ) Deferred tax liabilities (109,926 ) — — — — (22,459 ) (132,385 ) Other liabilities (9,274 ) — — (2,696 ) — — (11,970 ) Total fair value of consideration transferred $ 1,146,526 $ 704 $ — $ — $ — $ — $ 1,147,230
Summary of Identifiable Intangible Assets	The identifiable intangible assets recorded in connection with the closing of the Acquisition are based on valuations including customer relationships, patents and developed technology, and tradename and trademarks totaling $575.0 million. Customer relationships are amortized using an accelerated method over an estimated useful life of 20 years. Patents and developed technology and tradename and trademarks are on a straight-line basis over the respective useful lives of 10 and 20 years. (Amounts in thousands) Fair value Estimated useful lives Customer relationships $ 360,000 20 years Patents and developed technology 150,000 10 years Tradename and trademarks 65,000 20 years Total identifiable intangible assets $ 575,000
Summary of Unaudited Pro Forma Information	The unaudited pro forma information for the three and nine months ended December 31, 2019 presented below includes the effects of the Acquisition as if it had been consummated as of April 1, 2018, with adjustments to give effect to pro forma events that are directly attributable to the Acquisition. Three Months Ended Nine Months Ended (Amounts in thousands) December 31, 2019 December 31, 2019 Net sales $ 393,424 $ 1,389,440 Net income (loss) attributable to ADS 24,630 (146,147 )

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Dec. 31, 2020
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: December 31, 2020 March 31, 2020 (In thousands) Contract asset - product returns $ 874 $ 594 Refund liability 2,340 1,458

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories as of the periods presented consisted of the following: December 31, 2020 March 31, 2020 (In thousands) Raw materials $ 63,569 $ 66,524 Finished goods 175,291 215,874 Total inventories $ 238,860 $ 282,398

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Dec. 31, 2020
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: December 31, 2020 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 535 $ — $ 535 $ — Total assets at fair value on a recurring basis $ 535 $ — $ 535 $ — Liabilities: Derivative liabilities – diesel fuel contracts $ 188 $ — $ 188 $ — Total liabilities at fair value on a recurring basis $ 188 $ — $ 188 $ — March 31, 2020 Total Level 1 Level 2 Level 3 (In thousands) Assets: Derivative assets – diesel fuel contracts $ 36 $ — $ 36 $ — Total assets at fair value on a recurring basis $ 36 $ — $ 36 $ — Liabilities: Derivative liabilities - diesel fuel contracts $ 2,228 $ — $ 2,228 $ — Total liabilities at fair value on a recurring basis $ 2,228 $ — $ 2,228 $ —
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 11. Debt”) for the periods presented: December 31, 2020 March 31, 2020 Fair Value Carrying Value Fair Value Carrying Value (In thousands) (In thousands) Senior Notes $ 370,010 $ 350,000 $ 314,951 $ 350,000

Derivative Transactions (Tables

Derivative Transactions (Tables)	9 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Cash Settlements and Net (Gains) and Net Losses on Mark-to-Market Adjustments for Changes in Fair Value of Derivative Contracts	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 December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Diesel fuel option collars $ (1,082 ) $ (93 ) $ (2,537 ) $ (17 ) Interest rate swaps — — — 1,726 Foreign exchange forward contracts — — — (7 ) Total net unrealized mark-to-market (gains) loss $ (1,082 ) $ (93 ) $ (2,537 ) $ 1,702 Diesel fuel option collars 261 — 1,578 157 Foreign exchange forward contracts — — — 102 Interest rate swaps — — — 544 Total net realized loss $ 261 $ — $ 1,578 $ 803

Net Income Per Share and Stoc_2

Net Income Per Share and Stockholders' Equity (Tables)	9 Months Ended
	Dec. 31, 2020
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 December 31, Nine Months Ended December 31, (In thousands, except per share data) 2020 2019 2020 2019 NET INCOME PER SHARE—BASIC: Net income (loss) attributable to ADS $ 53,774 $ 23,288 $ 204,476 $ (195,479 ) Adjustments for: Dividends to redeemable convertible preferred stockholders (1,288 ) (1,334 ) (3,983 ) (9,530 ) Dividends paid to unvested restricted stockholders — (3 ) (2 ) (335 ) Net income (loss) available to common stockholders and participating securities 52,486 21,951 200,491 (205,344 ) Undistributed income allocated to participating securities (7,798 ) (2,822 ) (31,699 ) — Net income (loss) available to common stockholders – Basic $ 44,688 $ 19,129 $ 168,792 $ (205,344 ) Weighted average number of common shares outstanding – Basic 70,450 68,508 69,893 62,119 Net income (loss) per common share – Basic $ 0.63 $ 0.28 $ 2.42 $ (3.31 ) NET INCOME PER SHARE—DILUTED: Net income (loss) available to common stockholders – Diluted $ 44,688 $ 19,129 $ 168,792 $ (205,344 ) Weighted average number of common shares outstanding – Basic 70,450 68,508 69,893 62,119 Assumed exercise of stock options 886 641 745 — Restricted stock 250 149 215 — Weighted average number of common shares outstanding – Diluted 71,586 69,298 70,853 62,119 Net income (loss) per common share – Diluted $ 0.62 $ 0.28 $ 2.38 $ (3.31 ) Potentially dilutive securities excluded as anti-dilutive 14,347 14,915 14,807 14,084

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Summary of Purchases and Sales by ADS with Related Parties	The following tables summarizes the purchases by ADS from related parties and sales by ADS to related parties for the periods presented: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Purchases from South American Joint Venture $ 212 $ 76 $ 480 $ 584 Sales to South American Joint Venture 134 373 413 767 Purchases from Tigre USA 499 440 1,534 1,611

Debt (Tables)

Debt (Tables)	9 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-term debt as of the periods presented consisted of the following: December 31, 2020 March 31, 2020 (In thousands) Term Loan Facility $ 443,000 $ 648,250 Senior Notes 350,000 350,000 Revolving Credit Facility — 100,000 Equipment financing — 1,492 Total 793,000 1,099,742 Unamortized debt issuance costs (2,126 ) (2,419 ) Current maturities (7,000 ) (7,955 ) Long-term debt obligation $ 783,874 $ 1,089,368

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [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 December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Component of income before income taxes: Cost of goods sold $ 510 $ 319 $ 1,476 $ 620 Selling expenses 265 49 756 284 General and administrative expenses 4,038 3,504 13,676 7,980 Total stock-based compensation expense $ 4,813 $ 3,872 $ 15,908 $ 8,884 The following table summarizes stock-based compensation expense by award type for the periods presented: Three Months Ended December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Stock-based compensation expense: Equity-classified Stock Options $ 623 $ 701 $ 2,254 $ 1,952 Restricted Stock 1,214 1,075 3,975 2,674 Performance Units 2,622 1,776 8,676 3,349 Non-Employee Directors 354 320 1,003 909 Total stock-based compensation expense $ 4,813 $ 3,872 $ 15,908 $ 8,884
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: Nine Months Ended December 31, 2020 Common stock price $41.97 - $71.55 Expected stock price volatility 35.5% - 36.3% Risk-free interest rate 0.4% - 0.6% Weighted-average expected option life (years) 6.0 Dividend yield 0.5% - 0.9%

Business Segments Information (

Business Segments Information (Tables)	9 Months Ended
	Dec. 31, 2020
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 December 31, 2020 December 31, 2019 Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 254,209 $ (1,311 ) $ 252,898 $ 207,897 $ (342 ) $ 207,555 Infiltrator Water Technologies 98,409 (17,188 ) 81,221 72,083 (13,549 ) 58,534 International International - Pipe 33,729 (2,970 ) 30,759 28,340 — 28,340 International - Allied Products & Other 11,648 — 11,648 10,114 — 10,114 Total International 45,377 (2,970 ) 42,407 38,454 — 38,454 Allied Products & Other 109,619 — 109,619 88,881 — 88,881 Intersegment Eliminations (21,469 ) 21,469 — (13,891 ) 13,891 — Total Consolidated $ 486,145 $ — $ 486,145 $ 393,424 $ — $ 393,424 Nine Months Ended December 31, 2020 December 31, 2019 Net Sales Intersegment Net Sales Net Sales from External Customers Net Sales Intersegment Net Sales Net Sales from External Customers Pipe $ 819,994 $ (4,793 ) $ 815,201 $ 751,483 $ (684 ) $ 750,799 Infiltrator Water Technologies 306,548 (53,948 ) 252,600 136,972 (25,738 ) 111,234 International International - Pipe 96,271 (3,866 ) 92,405 92,242 — 92,242 International - Allied Products & Other 34,233 — 34,233 33,330 — 33,330 Total International 130,504 (3,866 ) 126,638 125,572 — 125,572 Allied Products & Other 344,532 — 344,532 315,432 — 315,432 Intersegment Eliminations (62,607 ) 62,607 — (26,422 ) 26,422 — Total Consolidated $ 1,538,971 $ — $ 1,538,971 $ 1,303,037 $ — $ 1,303,037
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 December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Segment adjusted gross profit Pipe $ 78,651 $ 61,025 $ 269,746 $ 192,764 Infiltrator Water Technologies 48,518 34,735 149,551 64,879 International 12,986 9,066 38,976 29,134 Allied Products & Other 55,158 42,818 176,006 157,626 Intersegment Eliminations (932 ) (881 ) (918 ) (1,859 ) Total $ 194,381 $ 146,763 $ 633,361 $ 442,544 Depreciation and amortization Pipe $ 11,298 $ 11,522 $ 34,201 $ 34,626 Infiltrator Water Technologies 3,132 2,563 9,270 4,422 International 1,402 1,462 4,002 4,559 Allied Products & Other (a) 19,930 15,625 59,848 30,825 Total $ 35,762 $ 31,172 $ 107,321 $ 74,432 Capital expenditures Pipe $ 4,095 $ 7,790 $ 12,237 $ 24,147 Infiltrator Water Technologies 22,651 12,499 40,630 16,382 International 556 191 1,303 2,068 Allied Products & Other (a) 1,414 191 3,505 3,696 Total $ 28,716 $ 20,671 $ 57,675 $ 46,293 (a) Includes depreciation, amortization and capital expenditures not allocated to a reportable segment. The amortization expense of Infiltrator Water Technologies 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 December 31, Nine Months Ended December 31, 2020 2019 2020 2019 (In thousands) (In thousands) Reconciliation of Segment Adjusted Gross Profit: Total Gross Profit $ 168,505 $ 123,358 $ 562,865 $ 207,724 Depreciation and amortization 16,432 16,025 49,318 45,417 ESOP and stock-based compensation expense 9,444 5,273 20,981 12,913 ESOP special dividend compensation — — — 168,610 COVID-19 related costs (a) — — 197 — Inventory step up related to Infiltrator Water Technologies acquisition — 2,107 — 7,880 Total Segment Adjusted Gross Profit $ 194,381 $ 146,763 $ 633,361 $ 442,544 (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) $ in Thousands	Jul. 31, 2019	Dec. 31, 2020USD ($)Segment	Sep. 30, 2020USD ($)	Apr. 01, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segment		3
Change in Accounting Principle, Accounting Standards Update, Adopted		true
Change in Accounting Principle, Accounting Standards Update, Adoption Date		Apr. 1, 2020
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect		false
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Adjustment to Retained deficit at the date of adoption		$ 785,359	$ 709,510		$ 537,485	$ 545,975	$ 511,756	$ 398,313
Retained Deficit [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Adjustment to Retained deficit at the date of adoption		$ (86,903)	$ (133,011)		(267,619)	$ (261,986)	$ (277,725)	$ 17,582
Cumulative Effect, Period of Adoption, Adjustment [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Adjustment to Retained deficit at the date of adoption					(779)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Retained Deficit [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Adjustment to Retained deficit at the date of adoption				$ 800	$ (779)
IWT [Member]
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Agreement and Plan of Merger date	Jul. 31, 2019	Jul. 31, 2019

Loss on Disposal of Assets an_3

Loss on Disposal of Assets and Costs from Exit and Disposal Activities - Summary of Loss on Disposal of Assets and Costs from Exit and Disposal Activities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Discontinued Operations And Disposal Groups [Abstract]
Headcount reduction	$ 300		$ 1,901
Total 2021 Restructuring Plan activities	300		1,901
Loss on other disposals and partial disposals of property, plant and equipment	680	$ 894	1,353	$ 2,045
Acquisition related severance and other costs		861		2,421
Total loss on disposal of assets and costs from exit and disposal activities	$ 980	$ 1,755	$ 3,254	$ 4,466

Loss on Disposal of Assets an_4

Loss on Disposal of Assets and Costs from Exit and Disposal Activities - Summary of Reconciliation of Restructuring Liability (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Discontinued Operations And Disposal Groups [Abstract]
Balance at the beginning of the period		$ 574	$ 1,696
Expenses	$ 300	1,901
Payments		(1,501)	(1,008)
Balance at the end of the period	$ 974	$ 974	$ 688

Loss on Disposal of Assets an_5

Loss on Disposal of Assets and Costs from Exit and Disposal Activities - Additional Information (Detail) $ in Millions	Dec. 31, 2020USD ($)
Other Liabilities [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Severance liability related to restructuring plan	$ 0.1

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 31, 2019	Dec. 31, 2020	Mar. 31, 2020
Business Acquisition [Line Items]
Goodwill		$ 598,957	$ 597,819
IWT [Member]
Business Acquisition [Line Items]
Agreement and Plan of Merger date	Jul. 31, 2019	Jul. 31, 2019
Total fair value of consideration transferred	$ 1,147,200
Amount payable to acquire	6,000
Amount receivable from acquire	6,600
Goodwill	495,800
Deferred tax liabilities	132,400
Step up of GAAP basis for fair market valuations	82,300
Deferred tax liabilities, acquired	50,100
Transaction costs related to Acquisition			$ 22,900
Transaction cost including tax		$ 7,100
Intangible assets	$ 575,000
IWT [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible asset, useful life	20 years
IWT [Member] | Patents and Developed Technology [Member]
Business Acquisition [Line Items]
Intangible asset, useful life	10 years
IWT [Member] | Tradename and Trademarks [Member]
Business Acquisition [Line Items]
Intangible asset, useful life	20 years
IWT [Member] | Finite-Lived Intangible Assets
Business Acquisition [Line Items]
Step up of GAAP basis for fair market valuations	$ 80,200

Acquisitions - Summary of Consi

Acquisitions - Summary of Consideration Transferred and Preliminary Purchase Price Allocation of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	17 Months Ended
	Dec. 31, 2020	Mar. 31, 2020	Jul. 31, 2019
Business Acquisition [Line Items]
Goodwill	$ 598,957	$ 597,819
IWT [Member]
Business Acquisition [Line Items]
Cash	57,375		$ 57,375
Total current asset, excluding cash	75,847		75,847
Property, plant and equipment, net	92,285		98,860
Goodwill	495,841		567,034
Intangible assets, net	575,000		475,000
Other assets	17,275		14,366
Total current liabilities	(22,038)		(22,756)
Deferred tax liabilities	(132,385)		(109,926)
Other liabilities	(11,970)		(9,274)
Total fair value of consideration transferred	1,147,230		$ 1,146,526
Adjustments to Property, Plant and Equipment	(6,575)
Goodwill, Increase to Purchase Price	704
Goodwill, Tax Adjustments	21,528
Adjustments to Intangible Assets	100,000
Adjustments to Right-of-use Assets, Other assets	2,909
Adjustments to Right-of-use Assets, Total current liabilities	(213)
Total current liabilities, Tax Adjustments	931
Adjustments to Right-of-use Assets, Other liabilities	(2,696)
Tax Adjustments	(22,459)
Increase to Purchase price	$ 704

Acquisitions - Summary of Ident

Acquisitions - Summary of Identifiable Intangible Assets (Detail) - IWT [Member] $ in Thousands	Jul. 31, 2019USD ($)
Business Acquisition [Line Items]
Total identifiable intangible assets, Preliminary fair value	$ 575,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets, Preliminary fair value	$ 360,000
Intangible asset, useful life	20 years
Patents and Developed Technology [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets, Preliminary fair value	$ 150,000
Intangible asset, useful life	10 years
Tradename and Trademarks [Member]
Business Acquisition [Line Items]
Total identifiable intangible assets, Preliminary fair value	$ 65,000
Intangible asset, useful life	20 years

Acquisitions - Summary of Unaud

Acquisitions - Summary of Unaudited Pro Forma Information (Detail) - IWT [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2019	Dec. 31, 2019
Business Acquisition Pro Forma Information Nonrecurring Adjustment [Line Items]
Net sales	$ 393,424	$ 1,389,440
Net income (loss) attributable to ADS	$ 24,630	$ (146,147)

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Contract Asset and Liability (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Contract With Customer Asset And Liability [Abstract]
Contract asset - product returns	$ 874	$ 594
Refund liability	$ 2,340	$ 1,458

Leases - Additional Information

Leases - Additional Information (Detail)	9 Months Ended
	Dec. 31, 2020
Minimum [Member]
Lessee Lease Description [Line Items]
Leases remaining term	1 year
Maximum [Member]
Lessee Lease Description [Line Items]
Leases remaining term	30 years
Maximum [Member] | Yard [Member]
Lessee Lease Description [Line Items]
Leases options to extend	5 years

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 63,569	$ 66,524
Finished goods	175,291	215,874
Total inventories	$ 238,860	$ 282,398

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($)	Dec. 31, 2020	Mar. 31, 2020
Inventory Disclosure [Abstract]
Work-in-process inventories	$ 0	$ 0

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Assets and Liabilities Carried at Fair Value (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value on a recurring basis	$ 535	$ 36
Total liabilities at fair value on a recurring basis	188	2,228
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value on a recurring basis	535	36
Total liabilities at fair value on a recurring basis	188	2,228
Diesel Fuel Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	535	36
Derivative liabilities	188	2,228
Diesel Fuel Contracts [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	535	36
Derivative liabilities	$ 188	$ 2,228

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - USD ($)	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair value of assets and liabilities, additional transfers	$ 0	$ 0

Fair Value Measurement - Summ_2

Fair Value Measurement - Summary of Carrying And Fair Value of Senior Notes (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	$ 370,010	$ 314,951
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	$ 350,000	$ 350,000

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		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Total net unrealized mark-to-market (gains) loss	$ (1,082)	$ (93)	$ (2,537)	$ 1,702
Total net realized loss	261		1,578	803
Diesel Fuel Option Collars [Member]
Derivatives, Fair Value [Line Items]
Total net unrealized mark-to-market (gains) loss	(1,082)	$ (93)	(2,537)	(17)
Total net realized loss	$ 261		$ 1,578	157
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Total net unrealized mark-to-market (gains) loss				1,726
Total net realized loss				544
Foreign Exchange Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Total net unrealized mark-to-market (gains) loss				(7)
Total net realized loss				$ 102

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		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
NET INCOME PER SHARE—BASIC:
Net income (loss) attributable to ADS	$ 53,774	$ 23,288	$ 204,476	$ (195,479)
Dividends to redeemable convertible preferred stockholders	(1,288)	(1,334)	(3,983)	(9,530)
Dividends paid to unvested restricted stockholders		(3)	(2)	(335)
Net income (loss) available to common stockholders and participating securities	52,486	21,951	200,491	(205,344)
Undistributed income allocated to participating securities	(7,798)	(2,822)	(31,699)
Net income (loss) available to common stockholders – Basic	$ 44,688	$ 19,129	$ 168,792	$ (205,344)
Weighted average number of common shares outstanding – Basic	70,450	68,508	69,893	62,119
Net income (loss) per common share – Basic	$ 0.63	$ 0.28	$ 2.42	$ (3.31)
NET INCOME PER SHARE—DILUTED:
Net income (loss) available to common stockholders – Diluted	$ 44,688	$ 19,129	$ 168,792	$ (205,344)
Weighted average number of common shares outstanding – Basic	70,450	68,508	69,893	62,119
Weighted average number of common shares outstanding – Diluted	71,586	69,298	70,853	62,119
Net income (loss) per common share – Diluted	$ 0.62	$ 0.28	$ 2.38	$ (3.31)
Potentially dilutive securities excluded as anti-dilutive	14,347	14,915	14,807	14,084
Exercise of Stock Options [Member]
NET INCOME PER SHARE—DILUTED:
Dilutive securities	886	641	745
Restricted Stock [Member]
NET INCOME PER SHARE—DILUTED:
Dilutive securities	250	149	215

Net Income Per Share and Stoc_4

Net Income Per Share and Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	Jun. 14, 2019	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Equity Class Of Treasury Stock [Line Items]
Cash dividend declared				$ 0.09
Dividend payment				$ 81,600
Additional stock-based compensation expense		$ 4,813	$ 3,872		$ 15,908	$ 8,884
Cost of Goods Sold - ESOP special dividend compensation and Selling, General and Administrative Expenses [Member]
Equity Class Of Treasury Stock [Line Items]
Additional stock-based compensation expense				$ 246,800
ESOP [Member]
Equity Class Of Treasury Stock [Line Items]
Number of redeemable convertible preferred stock allocated to ESOP participants				11.6
Amount of dividend from unallocated redeemable convertible preferred stock held in the ESOP trust to repay ESOP loan				$ 12,000
Special Dividend [Member]
Equity Class Of Treasury Stock [Line Items]
Cash dividend declared				$ 1
Dividend payable date	Jun. 14, 2019			Jun. 14, 2019
Dividend payable, date of record				Jun. 3, 2019
Special Dividend [Member] | ESOP [Member]
Equity Class Of Treasury Stock [Line Items]
Additional stock-based compensation expense						$ 246,800

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	9 Months Ended
	Dec. 31, 2020	Mar. 31, 2020
South American Joint Venture [Member]
Related Party Transaction [Line Items]
Maximum borrowings permitted under credit arrangement	$ 22,000,000
Debt, expiration date	Dec. 31, 2023
Percentage of debt guarantee	50.00%
Company's ownership percentage	50.00%
Maximum potential payment under guarantee	$ 11,000,000
Outstanding principal balance including letters of credit	10,100,000	$ 9,300,000
South American Joint Venture [Member] | US Dollar Denominated Loans [Member]
Related Party Transaction [Line Items]
Outstanding principal balance including letters of credit	$ 0
South American Joint Venture [Member] | Chilean Peso Denominated Loans [Member]
Related Party Transaction [Line Items]
Weighted average interest rate	3.50%
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Related Party Transaction [Line Items]
Maximum borrowings permitted under credit arrangement	$ 12,000,000
Revolving credit facility maturity date	Jun. 22, 2018
Debt, expiration date	Jun. 22, 2022
Outstanding principal balance including letters of credit	$ 0	$ 0
ADS Mexicana [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Related Party Transaction [Line Items]
Percentage of ownership in joint venture	49.00%
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] | ADS Mexicana [Member]
Related Party Transaction [Line Items]
Company's ownership percentage	51.00%

Related Party Transactions - Su

Related Party Transactions - Summary of Purchases and Sales by ADS with Related Parties (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
South American Joint Venture [Member]
Related Party Transaction [Line Items]
Purchases from related party	$ 212	$ 76	$ 480	$ 584
Sales to related party	134	373	413	767
Tigre USA [Member]
Related Party Transaction [Line Items]
Purchases from related party	$ 499	$ 440	$ 1,534	$ 1,611

Debt - Long-Term Debt (Detail)

Debt - Long-Term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Long-term debt , Gross	$ 793,000	$ 1,099,742
Unamortized debt issuance costs	(2,126)	(2,419)
Current maturities	(7,000)	(7,955)
Long-term debt obligation	783,874	1,089,368
Term Loan Facility [Member]
Debt Instrument [Line Items]
Long-term debt , Gross	443,000	648,250
Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt , Gross	$ 350,000	350,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt , Gross		100,000
Equipment Financing [Member]
Debt Instrument [Line Items]
Long-term debt , Gross		$ 1,492

Debt (Senior Secured Credit Fac

Debt (Senior Secured Credit Facility) - Additional Information (Detail) - USD ($)	9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Repayment of borrowings	$ 100,000,000	$ 177,900,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowings permitted under credit arrangement				$ 350,000,000
Repayment of borrowings	100,000,000
Outstanding letters of credit	11,000,000		$ 8,500,000
Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowings permitted under credit arrangement				50,000,000
Sublimit of Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowings permitted under credit arrangement				50,000,000
Term Loan Facility [Member]
Debt Instrument [Line Items]
Aggregate principal amount				$ 700,000,000
Repayment of borrowings	$ 205,300,000

Debt (Senior Notes) - Additiona

Debt (Senior Notes) - Additional Information (Detail) - 5.0% Senior Notes due 2027 [Member] $ 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 [Member]	9 Months Ended
	Dec. 31, 2020USD ($)
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) - USD ($) $ in Thousands, shares in Millions	Jul. 31, 2019	Jun. 14, 2019	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Effective income tax rate			27.10%	14.50%		27.80%	(13.20%)
Discrete income tax expense							$ 60,700
Additional stock-based compensation expense			$ 4,813	$ 3,872		$ 15,908	8,884
IWT [Member]
Income Taxes [Line Items]
Non-deductible transaction costs							1,800
Total purchase price	$ 132,400
Purchase price related to step up of GAAP basis for fair market valuations	82,300
Deferred tax liabilities acquired	50,100
Business combination, acquired federal net operating loss	24,000
IWT [Member] | Intangible Assets [Member]
Income Taxes [Line Items]
Purchase price related to step up of GAAP basis for fair market valuations	$ 80,200
Special Dividend [Member]
Income Taxes [Line Items]
Dividend payable date		Jun. 14, 2019			Jun. 14, 2019
Employee Stock Ownership Plan (ESOP) [Member]
Income Taxes [Line Items]
Non-deductible stock appreciation and deductible dividends							$ 242,900
Effective tax rate reduced by discrete event							35.10%
Employee Stock Ownership Plan (ESOP) [Member] | Special Dividend [Member]
Income Taxes [Line Items]
Shares allocated from the ESOP from discrete event				11.6			11.6
Additional stock-based compensation expense							$ 246,800

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 4,813	$ 3,872	$ 15,908	$ 8,884
Equity-Classified Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	623	701	2,254	1,952
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	1,214	1,075	3,975	2,674
Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	2,622	1,776	8,676	3,349
Non-Employee Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	354	320	1,003	909
Cost of Goods Sold [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	510	319	1,476	620
Selling Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	265	49	756	284
General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 4,038	$ 3,504	$ 13,676	$ 7,980

Stock-Based Compensation (2017

Stock-Based Compensation (2017 Omnibus Plan) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	May 24, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards	$ (90)	$ (38)	$ (487)	$ (129)
2017 Omnibus Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock awards, Shares	100,000		100,000
Restricted stock awards	$ 100		$ 5,800
Number of stock options granted, Value	$ 100		$ 3,400
2017 Omnibus Plan [Member] | Performance Units [Member] | IWT [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of performance units granted	100,000		100,000
Number of performance units granted, Value	$ 100		$ 5,300
2017 Omnibus Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock approved for issuance					3,500,000
Number of nonqualified stock options granted	100,000		300,000

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Assumption Used to Estimate Fair Value of Stock Options (Detail)	9 Months Ended
	Dec. 31, 2020$ / shares
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Expected stock price volatility, minimum	35.50%
Expected stock price volatility, maximum	36.30%
Risk-free interest rate, minimum	0.40%
Risk-free interest rate, maximum	0.60%
Weighted-average expected option life (years)	6 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Common stock price	$ 41.97
Dividend yield	0.50%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Common stock price	$ 71.55
Dividend yield	0.90%

Business Segments Information -

Business Segments Information - Additional Information (Detail)	9 Months Ended
	Dec. 31, 2020Segment
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		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Net Sales	$ 486,145	$ 393,424	$ 1,538,971	$ 1,303,037
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	486,145	393,424	1,538,971	1,303,037
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net Sales	(21,469)	(13,891)	(62,607)	(26,422)
Pipe Segment [Member]
Segment Reporting Information [Line Items]
Net Sales	252,898	207,555	815,201	750,799
Pipe Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	254,209	207,897	819,994	751,483
Pipe Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net Sales	(1,311)	(342)	(4,793)	(684)
Infiltrator Water Technologies Segment [Member]
Segment Reporting Information [Line Items]
Net Sales	81,221	58,534	252,600	111,234
Infiltrator Water Technologies Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	98,409	72,083	306,548	136,972
Infiltrator Water Technologies Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net Sales	(17,188)	(13,549)	(53,948)	(25,738)
International Segment [Member]
Segment Reporting Information [Line Items]
Net Sales	42,407	38,454	126,638	125,572
International Segment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	45,377	38,454	130,504	125,572
International Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net Sales	(2,970)		(3,866)
International Segment [Member] | Pipe [Member]
Segment Reporting Information [Line Items]
Net Sales	30,759	28,340	92,405	92,242
International Segment [Member] | Pipe [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	33,729	28,340	96,271	92,242
International Segment [Member] | Pipe [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net Sales	(2,970)		(3,866)
International Segment [Member] | Allied Products and Other [Member]
Segment Reporting Information [Line Items]
Net Sales	11,648	10,114	34,233	33,330
International Segment [Member] | Allied Products and Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	11,648	10,114	34,233	33,330
Allied Products and Other [Member]
Segment Reporting Information [Line Items]
Net Sales	109,619	88,881	344,532	315,432
Allied Products and Other [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Sales	$ 109,619	$ 88,881	$ 344,532	$ 315,432

Business Segments Information_3

Business Segments Information - Schedule of Financial Information Attributable to Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Segment adjusted gross profit	$ 194,381	$ 146,763	$ 633,361	$ 442,544
Depreciation and amortization	35,762	31,172	107,321	74,432
Capital expenditures	28,716	20,671	57,675	46,293
Operating Segments [Member] | Pipe Segment [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	78,651	61,025	269,746	192,764
Depreciation and amortization	11,298	11,522	34,201	34,626
Capital expenditures	4,095	7,790	12,237	24,147
Operating Segments [Member] | Infiltrator Water Technologies Segment [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	48,518	34,735	149,551	64,879
Depreciation and amortization	3,132	2,563	9,270	4,422
Capital expenditures	22,651	12,499	40,630	16,382
Operating Segments [Member] | International Segment [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	12,986	9,066	38,976	29,134
Depreciation and amortization	1,402	1,462	4,002	4,559
Capital expenditures	556	191	1,303	2,068
Operating Segments [Member] | Allied Products and Other [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	55,158	42,818	176,006	157,626
Depreciation and amortization	19,930	15,625	59,848	30,825
Capital expenditures	1,414	191	3,505	3,696
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	$ (932)	$ (881)	$ (918)	$ (1,859)

Business Segments Information_4

Business Segments Information - Reconciliation of Gross Profit to Segment Adjusted Gross Profit (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	$ 168,505	$ 123,358	$ 562,865	$ 207,724
Depreciation and amortization	16,432	16,025	49,318	45,417
ESOP and stock-based compensation expense	9,444	5,273	20,981	12,913
ESOP special dividend compensation				168,610
COVID-19 related costs			197
Inventory step up				7,880
Total Segment Adjusted Gross Profit	$ 194,381	146,763	$ 633,361	442,544
Infiltrator Water Technologies [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Inventory step up		$ 2,107		$ 7,880

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - $ / shares	3 Months Ended			9 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Cash dividend declared		$ 0.09	$ 0.09	$ 0.27	$ 1.27
Scenario Forecast [Member]
Subsequent Event [Line Items]
Cash dividend declared	$ 0.09
Dividend payable date	Mar. 15, 2021
Dividend payable, date of record	Mar. 1, 2021