Segments - Net Sales by Main Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Revenue from external customers
Total net sales	$ 1,153,595	$ 751,191	$ 3,346,222	$ 2,366,620
Wallboard
Revenue from external customers
Total net sales	415,132	311,122	1,219,789	969,722
Ceilings
Revenue from external customers
Total net sales	139,894	103,711	418,831	330,480
Steel framing
Revenue from external customers
Total net sales	282,764	103,957	751,040	325,782
Complementary products
Revenue from external customers
Total net sales	$ 315,805	$ 232,401	$ 956,562	$ 740,636