Segments - Net sales by major geographic area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$ 1,150,551	$ 812,856	$ 2,192,627	$ 1,615,429
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	988,103	684,131	1,850,893	1,363,452
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net sales	$ 162,448	$ 128,725	$ 341,734	$ 251,977