Segment Information - Financial Information Related to Operations by Segment (Detail) $ in Thousands	3 Months Ended
	Jun. 30, 2024 USD ($) kt	Jun. 30, 2023 USD ($) kt	Mar. 31, 2024 USD ($)
Segment Reporting Information [Line Items]
Revenue	$ 608,689	$ 601,521
Operating Earnings	194,584	179,154
Corporate General and Administrative Expense	(15,649)	(11,679)
Other Non-Operating Income (Loss)	2,683	213
Earnings Before Interest and Income Taxes	181,618	167,688
Interest Expense, net	(10,684)	(12,239)
Earnings before Income Taxes	170,934	155,449
Capital Expenditures	33,128	35,999
Depreciation, Depletion and Amortization	38,350	36,682
Identifiable Assets	3,042,867		$ 2,947,019
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	676,043	663,910
Depreciation, Depletion and Amortization	38,350	36,682
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(38,044)	(35,266)
Revenue	38,044	35,266
Consolidation, Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(29,310)	(27,123)
Cement [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	$ 339,162	$ 329,032
Cement Sales Volume | kt	1,947	2,013
Operating Earnings	$ 89,125	$ 74,061
Capital Expenditures	18,794	18,368
Depreciation, Depletion and Amortization	22,917	$ 21,679
Identifiable Assets	$ 2,121,374		2,042,499
Cement [Member] | Operating Segments [Member] | Wholly-Owned [Member]
Segment Reporting Information [Line Items]
Cement Sales Volume | kt	1,767	1,848
Operating Earnings	$ 81,409	$ 70,902
Cement [Member] | Operating Segments [Member] | Joint Venture [Member]
Segment Reporting Information [Line Items]
Cement Sales Volume | kt	180	165
Operating Earnings	$ 7,716	$ 3,159
Cement [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	10,280	10,137
Concrete and Aggregates [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	64,815	70,453
Operating Earnings	2,980	7,034
Capital Expenditures	6,589	3,220
Depreciation, Depletion and Amortization	4,530	5,031
Identifiable Assets	242,607		225,485
Concrete and Aggregates [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	3,777	3,038
Gypsum Wallboard [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	217,826	219,097
Operating Earnings	93,976	90,857
Capital Expenditures	3,280	11,028
Depreciation, Depletion and Amortization	6,473	5,461
Identifiable Assets	429,773		432,122
Recycled Paperboard [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	54,240	45,328
Operating Earnings	8,503	7,202
Capital Expenditures	3,561	3,268
Depreciation, Depletion and Amortization	3,690	3,719
Identifiable Assets	167,405	170,832
Recycled Paperboard [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	23,987	22,091
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	904	115
Depreciation, Depletion and Amortization	740	$ 792
Other, net [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	$ 81,708		$ 76,081