Financial Information Related to Operations by Segment (Detail) $ in Thousands	3 Months Ended
	Jun. 30, 2022 USD ($) kt	Jun. 30, 2021 USD ($) kt	Mar. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Revenue	$ 561,387	$ 475,770
Less: Joint Venture Revenue	(26,315)	(22,691)
Operating Earnings	155,964	134,481
Corporate General and Administrative Expense	(11,820)	(9,468)
Other Non-Operating Income	(635)	3,678
Earnings Before Interest and Income Taxes	143,509	128,691
Interest Expense, net	(7,330)	(6,972)
Earnings Before Income Taxes	136,179	121,719
Capital Expenditures	14,914	11,935
Depreciation, Depletion and Amortization	34,229	31,944
Identifiable Assets	2,770,859		$ 2,579,652
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	616,534	524,543
Depreciation, Depletion and Amortization	34,229	31,944
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	(28,832)	(26,082)
Revenue	28,832	26,082
Cement [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	$ 284,516	$ 270,255
Cement Sales Volume | kt	1,993	2,036
Operating Earnings	$ 62,348	$ 62,547
Capital Expenditures	8,986	7,967
Depreciation, Depletion and Amortization	20,053	$ 19,531
Identifiable Assets	$ 1,886,113		1,860,649
Cement [Member] | Operating Segments [Member] | Wholly-Owned [Member]
Segment Reporting Information [Line Items]
Cement Sales Volume | kt	1,805	1,852
Operating Earnings	$ 57,250	$ 54,577
Cement [Member] | Operating Segments [Member] | Joint Venture [Member]
Segment Reporting Information [Line Items]
Cement Sales Volume | kt	188	184
Operating Earnings	$ 5,098	$ 7,970
Cement [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	6,291	7,833
Concrete and Aggregates [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	61,618	44,754
Operating Earnings	5,732	5,344
Capital Expenditures	652	546
Depreciation, Depletion and Amortization	4,201	2,578
Identifiable Assets	214,042		89,405
Gypsum Wallboard [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	216,327	166,267
Operating Earnings	84,068	63,253
Capital Expenditures	4,079	1,694
Depreciation, Depletion and Amortization	5,563	5,396
Identifiable Assets	401,056		397,486
Paperboard [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue	54,073	43,267
Operating Earnings	3,816	3,337
Capital Expenditures	837	1,117
Depreciation, Depletion and Amortization	3,717	3,668
Identifiable Assets	177,082		180,025
Paperboard [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	22,541	18,249
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	360	611
Depreciation, Depletion and Amortization	695	$ 771
Other, net [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	$ 92,566		$ 52,087