Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2024	Jan. 31, 2024	Oct. 31, 2023	Jul. 31, 2023	Apr. 30, 2023	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Revenue from External Customer [Line Items]
Total net sales	$ 1,413,029	$ 1,258,348	$ 1,420,930	$ 1,409,600	$ 1,304,102	$ 1,234,618	$ 1,430,979	$ 1,359,553	$ 5,501,907	$ 5,329,252	$ 4,634,875
Wallboard
Revenue from External Customer [Line Items]
Total net sales									2,263,337	2,151,505	1,710,851
Complementary products
Revenue from External Customer [Line Items]
Total net sales									1,650,689	1,537,617	1,328,383
Steel framing
Revenue from External Customer [Line Items]
Total net sales									892,730	1,011,309	1,027,941
Ceilings
Revenue from External Customer [Line Items]
Total net sales									$ 695,151	$ 628,821	$ 567,700