Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2023	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Apr. 30, 2022	Jan. 31, 2022	Oct. 31, 2021	Jul. 31, 2021	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Revenue from External Customer [Line Items]
Total net sales	$ 1,304,102	$ 1,234,618	$ 1,430,979	$ 1,359,553	$ 1,288,653	$ 1,153,595	$ 1,150,551	$ 1,042,076	$ 5,329,252	$ 4,634,875	$ 3,298,823
Wallboard
Revenue from External Customer [Line Items]
Total net sales									2,151,505	1,710,851	1,346,648
Complementary products
Revenue from External Customer [Line Items]
Total net sales									1,537,617	1,328,383	1,031,361
Steel framing
Revenue from External Customer [Line Items]
Total net sales									1,011,309	1,027,941	469,048
Ceilings
Revenue from External Customer [Line Items]
Total net sales									$ 628,821	$ 567,700	$ 451,766