Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Revenue from external customers
Total net sales	$ 1,409,600	$ 1,359,553
Wallboard
Revenue from external customers
Total net sales	571,425	521,554
Complementary products
Revenue from external customers
Total net sales	426,210	395,828
Steel framing
Revenue from external customers
Total net sales	236,760	274,896
Ceilings
Revenue from external customers
Total net sales	$ 175,205	$ 167,275