Segment Breakdown of Goodwill (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Mar. 31, 2023
Segment Reporting Information [Line Items]
Goodwill	$ 392,599	$ 380,711
Cement [Member]
Segment Reporting Information [Line Items]
Goodwill	227,669	215,781
Concrete and Aggregates [Member]
Segment Reporting Information [Line Items]
Goodwill	40,774	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