Financial Information Related to Operations by Segment (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2023 USD ($) kt	Dec. 31, 2022 USD ($) kt	Dec. 31, 2023 USD ($) kt	Dec. 31, 2022 USD ($) kt	Mar. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Revenue	$ 558,833	$ 511,487	$ 1,782,590	$ 1,677,942
Operating Earnings	189,913	170,147	588,431	527,506
Corporate General and Administrative Expense	(14,201)	(12,497)	(42,456)	(37,944)
Other Non-Operating Income	1,019	2,210	2,837	911
Earnings Before Interest and Income Taxes	176,731	159,860	548,812	490,473
Interest Expense, net	(10,128)	(8,932)	(32,571)	(24,842)
Earnings before Income Taxes	166,603	150,928	516,241	465,631
Capital Expenditures	22,435	17,702	87,848	60,951
Depreciation, Depletion and Amortization			111,347	103,689
Identifiable Assets	2,890,340		2,890,340		$ 2,781,002
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	617,862	571,279	1,964,659	1,855,197
Depreciation, Depletion and Amortization	37,468	34,815	111,347	103,689
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(32,346)	(32,172)	(99,356)	(98,190)
Revenue	32,346	32,172	99,356	98,190
Consolidation, Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(26,683)	(27,620)	(82,713)	(79,065)
Cement [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	$ 308,654	$ 256,313	$ 998,437	$ 860,289
Cement Sales Volume | kt	1,824	1,699	5,966	5,837
Operating Earnings	$ 105,566	$ 72,315	$ 301,056	$ 233,442
Capital Expenditures	11,571	7,278	38,288	21,157
Depreciation, Depletion and Amortization	22,514	$ 20,582	66,380	$ 60,893
Identifiable Assets	$ 1,997,649		$ 1,997,649		1,905,227
Cement [Member] | Operating Segments [Member] | Wholly-Owned [Member]
Segment Reporting Information [Line Items]
Cement Sales Volume | kt	1,663	1,527	5,470	5,313
Operating Earnings	$ 96,281	$ 60,938	$ 278,266	$ 209,811
Cement [Member] | Operating Segments [Member] | Joint Venture [Member]
Segment Reporting Information [Line Items]
Cement Sales Volume | kt	161	172	496	524
Operating Earnings	$ 9,285	$ 11,377	$ 22,790	$ 23,631
Cement [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	7,804	7,719	27,192	26,371
Concrete and Aggregates [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	61,186	55,176	201,526	186,407
Operating Earnings	1,760	2,692	13,434	15,700
Capital Expenditures	1,207	2,128	10,281	16,468
Depreciation, Depletion and Amortization	4,857	4,402	14,850	12,954
Identifiable Assets	229,998		229,998		234,767
Concrete and Aggregates [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	3,414	0	10,235	0
Gypsum Wallboard [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	200,969	212,016	629,299	652,981
Operating Earnings	75,063	87,335	251,625	261,164
Capital Expenditures	7,386	7,307	23,866	19,777
Depreciation, Depletion and Amortization	5,611	5,387	16,620	16,539
Identifiable Assets	412,092		412,092		421,425
Recycled Paperboard [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	47,053	47,774	135,397	155,520
Operating Earnings	7,524	7,805	22,316	17,200
Capital Expenditures	1,868	463	7,733	2,318
Depreciation, Depletion and Amortization	3,694	3,738	11,121	11,197
Identifiable Assets	168,120		168,120		163,797
Recycled Paperboard [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	21,128	24,453	61,929	71,819
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	403	526	7,680	1,231
Depreciation, Depletion and Amortization	792	$ 706	2,376	$ 2,106
Other, net [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	$ 82,481		$ 82,481		$ 55,786