Consolidated Statements of Earnings (Detail) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Revenue	$ 428,020	$ 370,597
Cost of Goods Sold	327,041	295,268
Gross Profit	100,979	75,329
Equity in Earnings of Unconsolidated Joint Venture	7,796	9,432
Corporate General and Administrative Expense	(17,789)	(21,254)
Gain on Sale of Businesses	51,973
Other Non-Operating Income (Loss)	(127)	200
Interest Expense, net	(14,041)	(8,846)
Earnings before Income Taxes	128,791	54,861
Income Taxes	(32,585)	(13,557)
Net Earnings	96,206	41,304
Net Actuarial Change in Benefit Plans, net of tax	25	33
Comprehensive Earnings	96,231	41,337
Eliminations [Member]
Equity in Earnings of Unconsolidated Joint Venture	(7,796)	(9,432)
Equity in Earnings of Subsidiaries	(63,684)	(55,742)
Earnings before Income Taxes	(71,480)	(65,174)
Net Earnings	(71,480)	(65,174)
Net Actuarial Change in Benefit Plans, net of tax	(25)	(33)
Comprehensive Earnings	(71,505)	(65,207)
Parent [Member] \| Reportable Legal Entities [Member]
Equity in Earnings of Unconsolidated Joint Venture	7,796	9,432
Equity in Earnings of Subsidiaries	63,684	55,742
Corporate General and Administrative Expense	(14,411)	(20,968)
Gain on Sale of Businesses	51,973
Other Non-Operating Income (Loss)	(375)	426
Interest Expense, net	(14,028)	(8,834)
Earnings before Income Taxes	94,639	35,798
Income Taxes	1,567	5,506
Net Earnings	96,206	41,304
Net Actuarial Change in Benefit Plans, net of tax	25	33
Comprehensive Earnings	96,231	41,337
Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Revenue	426,989	370,597
Cost of Goods Sold	324,692	295,268
Gross Profit	102,297	75,329
Equity in Earnings of Unconsolidated Joint Venture	7,796	9,432
Corporate General and Administrative Expense	(3,260)	(286)
Other Non-Operating Income (Loss)	67	(226)
Interest Expense, net	(13)	(12)
Earnings before Income Taxes	106,887	84,237
Income Taxes	(34,502)	(19,063)
Net Earnings	72,385	65,174
Net Actuarial Change in Benefit Plans, net of tax	25	33
Comprehensive Earnings	72,410	$ 65,207
Non Guarantor Subsidiaries [Member] \| Reportable Legal Entities [Member]
Revenue	1,031
Cost of Goods Sold	2,349
Gross Profit	(1,318)
Corporate General and Administrative Expense	(118)
Other Non-Operating Income (Loss)	181
Earnings before Income Taxes	(1,255)
Income Taxes	350
Net Earnings	(905)
Comprehensive Earnings	$ (905)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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