Inventories - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2025	Mar. 31, 2025
Inventory [Line Items]
Inventories	$ 393,401	$ 415,175
Raw Materials and Material-in-Progress [Member]
Inventory [Line Items]
Inventories	151,324	164,683
Finished Cement [Member]
Inventory [Line Items]
Inventories	63,249	67,711
Aggregates [Member]
Inventory [Line Items]
Inventories	16,371	17,681
Gypsum Wallboard [Member]
Inventory [Line Items]
Inventories	6,087	5,708
Recycled Paperboard [Member]
Inventory [Line Items]
Inventories	7,124	7,814
Repair Parts and Supplies [Member]
Inventory [Line Items]
Inventories	125,182	126,983
Fuel and Coal [Member]
Inventory [Line Items]
Inventories	$ 24,064	$ 24,595