Business Segments - Segment Breakdown of Goodwill (Detail) - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information [Line Items]
Goodwill	$ 469,894	$ 392,569
Cement [Member]
Segment Reporting Information [Line Items]
Goodwill	227,639	227,639
Concrete and Aggregates [Member]
Segment Reporting Information [Line Items]
Goodwill	118,099	40,774
Gypsum Wallboard [Member]
Segment Reporting Information [Line Items]
Goodwill	116,618	116,618
Recycled Paperboard [Member]
Segment Reporting Information [Line Items]
Goodwill	$ 7,538	$ 7,538