v3.26.1
Business Segments - Financial Information Related to Operations by Segment (Detail)
$ in Thousands
 12 Months Ended
Mar. 31, 2026
USD ($)
kt
Mar. 31, 2025
USD ($)
kt
Mar. 31, 2024
USD ($)
kt
Segment Reporting Information [Line Items]      
Revenue $ 2,308,658 $ 2,260,508 $ 2,259,297
Corporate General and Administrative Expense (89,182) (73,942) (59,795)
Other Non-Operating Earnings 5,108 6,420 3,087
Interest Expense, net (46,482) (40,526) (42,257)
Earnings Before Income Taxes 541,976 591,485 617,937
Capital Expenditures 416,739 195,281 120,305
Depreciation, Depletion and Amortization 164,746 158,902 149,832
Segment Assets 3,842,244 3,264,588 2,947,019
External Customers [Member]      
Segment Reporting Information [Line Items]      
Revenue 2,308,658 2,260,508 2,259,297
Intersegment [Member]      
Segment Reporting Information [Line Items]      
Revenue 134,596 139,770 130,654
Joint Venture [Member]      
Segment Reporting Information [Line Items]      
Revenue 119,341 110,943 112,736
Operating Segments [Member]      
Segment Reporting Information [Line Items]      
Revenue 2,562,595 2,511,221 2,502,687
Freight and Delivery 273,782 269,685 278,071
Parts, Supplies, and Services (Includes Maintenance) 302,769 302,269 282,162
Energy 200,889 196,329 217,670
Raw Materials 461,673 468,167 461,725
Labor and Fixed Costs 301,030 282,862 268,803
Depreciation, Depletion and Amortization [1] 159,639 155,653 146,715
Purchased Cement 79,365 77,059 86,219
Other Segment Items 110,916 59,664 44,420
Segment Operating Earnings 672,532 699,533 716,902
Intersegment Eliminations [Member]      
Segment Reporting Information [Line Items]      
Revenue (134,596) (139,770) (130,654)
Consolidation, Eliminations [Member]      
Segment Reporting Information [Line Items]      
Revenue (119,341) (110,943) (112,736)
Cement [Member] | External Customers [Member]      
Segment Reporting Information [Line Items]      
Revenue 1,144,031 1,053,620 1,077,918
Cement [Member] | Intersegment [Member]      
Segment Reporting Information [Line Items]      
Revenue 36,011 36,799 35,363
Cement [Member] | Joint Venture [Member]      
Segment Reporting Information [Line Items]      
Revenue 119,341 110,943 112,736
Cement [Member] | Operating Segments [Member]      
Segment Reporting Information [Line Items]      
Revenue $ 1,299,383 $ 1,201,362 $ 1,226,017
Cement Sales Volume | kt 7,471 6,912 7,289
Operating Earnings $ 328,306 $ 319,456 $ 338,349
Capital Expenditures 257,850 139,965 65,442
Freight and Delivery 104,342 90,996 94,031
Parts, Supplies, and Services (Includes Maintenance) 223,964 231,530 217,393
Energy 141,867 140,754 154,925
Raw Materials 99,956 84,669 87,154
Labor and Fixed Costs 173,562 162,741 155,118
Depreciation, Depletion and Amortization 94,380 91,817 [1] 89,138 [1]
Purchased Cement 79,365 77,059 86,219
Other Segment Items 53,641 2,340 3,690
Segment Operating Earnings 328,306 319,456 338,349
Segment Assets $ 2,361,230 $ 2,172,459 $ 2,042,499
Cement [Member] | Operating Segments [Member] | Wholly-Owned [Member]      
Segment Reporting Information [Line Items]      
Cement Sales Volume | kt 6,770 6,237 6,610
Operating Earnings $ 308,317 $ 293,060 $ 306,768
Cement [Member] | Operating Segments [Member] | Joint Venture [Member]      
Segment Reporting Information [Line Items]      
Cement Sales Volume | kt 701 675 679
Operating Earnings $ 19,989 $ 26,396 $ 31,581
Concrete and Aggregates [Member] | External Customers [Member]      
Segment Reporting Information [Line Items]      
Revenue 283,275 237,723 240,012
Concrete and Aggregates [Member] | Intersegment [Member]      
Segment Reporting Information [Line Items]      
Revenue 16,229 13,913 12,940
Concrete and Aggregates [Member] | Joint Venture [Member]      
Segment Reporting Information [Line Items]      
Revenue 0 0 0
Concrete and Aggregates [Member] | Operating Segments [Member]      
Segment Reporting Information [Line Items]      
Revenue 299,504 251,636 252,952
Capital Expenditures 26,455 20,571 15,103
Freight and Delivery 28,664 32,593 33,976
Parts, Supplies, and Services (Includes Maintenance) 51,781 39,109 31,246
Energy 9,663 7,562 7,641
Raw Materials 109,946 109,587 112,447
Labor and Fixed Costs 38,394 36,722 31,014
Depreciation, Depletion and Amortization 28,159 23,247 [1] 19,728 [1]
Purchased Cement 0 0
Other Segment Items 20,033 11,581 4,499
Segment Operating Earnings 12,864 (8,765) 12,401
Segment Assets 404,766 408,792 225,485
Gypsum Wallboard [Member] | External Customers [Member]      
Segment Reporting Information [Line Items]      
Revenue 764,493 846,499 839,530
Gypsum Wallboard [Member] | Intersegment [Member]      
Segment Reporting Information [Line Items]      
Revenue 0 0 0
Gypsum Wallboard [Member] | Joint Venture [Member]      
Segment Reporting Information [Line Items]      
Revenue 0 0 0
Gypsum Wallboard [Member] | Operating Segments [Member]      
Segment Reporting Information [Line Items]      
Revenue 764,493 846,499 839,530
Capital Expenditures 118,102 15,843 29,127
Freight and Delivery 140,719 146,000 149,441
Parts, Supplies, and Services (Includes Maintenance) 21,472 19,032 22,337
Energy 32,338 33,978 37,984
Raw Materials 172,058 179,142 178,340
Labor and Fixed Costs 62,813 61,968 59,796
Depreciation, Depletion and Amortization 23,890 25,807 [1] 23,038 [1]
Purchased Cement 0
Other Segment Items 24,372 29,808 34,058
Segment Operating Earnings 286,831 350,764 334,536
Segment Assets 522,861 429,268 432,122
Recycled Paperboard [Member] | External Customers [Member]      
Segment Reporting Information [Line Items]      
Revenue 116,859 122,666 101,837
Recycled Paperboard [Member] | Intersegment [Member]      
Segment Reporting Information [Line Items]      
Revenue 82,356 89,058 82,351
Recycled Paperboard [Member] | Joint Venture [Member]      
Segment Reporting Information [Line Items]      
Revenue 0 0 0
Recycled Paperboard [Member] | Operating Segments [Member]      
Segment Reporting Information [Line Items]      
Revenue 199,215 211,724 184,188
Capital Expenditures 11,002 15,193 10,085
Freight and Delivery 57 96 623
Parts, Supplies, and Services (Includes Maintenance) 5,552 12,598 11,186
Energy 17,021 14,035 17,120
Raw Materials 79,713 94,769 83,784
Labor and Fixed Costs 26,261 21,431 22,875
Depreciation, Depletion and Amortization 13,210 14,782 [1] 14,811 [1]
Purchased Cement 0
Other Segment Items 12,870 15,935 2,173
Segment Operating Earnings 44,531 38,078 31,616
Segment Assets 169,630 166,673 170,832
Corporate and Other [Member]      
Segment Reporting Information [Line Items]      
Capital Expenditures 3,330 3,709 548
Segment Assets $ 383,757 $ 87,396 $ 76,081
[1] Depreciation, Depletion, and Amortization for corporate assets was $5,107, $3,249, and $3,117, in fiscal 2026, 2025, and 2024, respectively. These amounts are included in Corporate General and Administrative Expense.