Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities
Net (loss) income	$ (195,330)	$ 79,573
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	74,432	52,912
Deferred income taxes	(1,098)	2,316
Loss on disposal of assets and costs from exit and disposal activities	4,466	1,572
ESOP and stock-based compensation	27,365	16,142
ESOP special dividend compensation	246,752
Amortization of deferred financing charges	34,380	561
Inventory step up related to Infiltrator Water Technologies acquisition	7,880
Fair market value adjustments to derivatives	903	1,976
Equity in net (income) loss of unconsolidated affiliates	(538)	225
Other operating activities	(6,013)	(3,493)
Changes in working capital:
Receivables	50,865	16,768
Inventories	43,317	15,705
Prepaid expenses and other current assets	(1,417)	(2,562)
Accounts payable, accrued expenses, and other liabilities	10,354	(33,673)
Net cash provided by operating activities	296,318	148,022
Cash Flows from Investing Activities
Capital expenditures	(46,293)	(31,130)
Acquisition of Infiltrator Water Technologies, net of cash acquired	(1,089,322)
Other investing activities	(247)	1,109
Net cash used in investing activities	(1,135,862)	(30,021)
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	(50,000)
Proceeds from Senior Notes	350,000
Proceeds from Credit Agreement	177,900
Payments on Credit Agreement	(177,900)
Debt issuance costs	(34,606)
Payments on Prudential Senior Notes	(100,000)	(25,000)
Payments on finance lease obligations	(18,424)	(17,791)
Proceeds from common stock offering, net of offering costs	293,648
Acquisition of noncontrolling interest in BaySaver		(8,821)
Cash dividends paid	(83,846)	(21,084)
Proceeds from exercise of stock options	6,280	3,937
Other financing activities	(236)	(1,620)
Net cash provided by (used in) financing activities	928,416	(115,379)
Effect of exchange rate changes on cash	549	(451)
Net change in cash	89,421	2,171
Cash at beginning of period	8,891	17,587
Cash at end of period	98,312	19,758
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for income taxes	9,450	27,459
Cash paid for interest	23,992	11,506
Non-cash operating, investing and financing activities:
Balance in accounts payable for the acquisition of property, plant and equipment	4,129	2,381
PNC Credit Agreement [Member]
Cash Flows from Financing Activities
Proceeds from Credit Agreement	253,900	331,600
Payments on Credit Agreement	$ (388,300)	$ (376,600)