Business Segments Information - Schedule of Financial Information Attributable to Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Segment adjusted gross profit	$ 210,045	$ 123,907
Depreciation and amortization	35,781	16,694
Capital expenditures	10,295	9,723
Operating Segments [Member] \| Pipe Segment [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	90,599	57,493
Depreciation and amortization	11,360	11,547
Capital expenditures	4,231	6,974
Operating Segments [Member] \| Infiltrator Water Technologies Segment [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	47,928
Depreciation and amortization	3,133
Capital expenditures	4,198
Operating Segments [Member] \| International Segment [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	11,408	9,227
Depreciation and amortization	1,298	1,507
Capital expenditures	450	1,254
Operating Segments [Member] \| Allied Products and Other [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	60,468	57,187
Depreciation and amortization	19,990	3,640
Capital expenditures	1,416	$ 1,495
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Segment adjusted gross profit	$ (358)

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (b)
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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