Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2022	Jul. 31, 2021
Revenue from external customers
Total net sales	$ 1,359,553	$ 1,042,076
Wallboard
Revenue from external customers
Total net sales	521,554	390,135
Ceilings
Revenue from external customers
Total net sales	167,275	138,071
Steel framing
Revenue from external customers
Total net sales	274,896	196,276
Complementary products
Revenue from external customers
Total net sales	$ 395,828	$ 317,594