Segments - Net Sales, Adjusted EBITDA and Certain Other Measures (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	May 01, 2019
Segment information
Net sales	$ 847,176	$ 778,144
Gross Profit	273,654	244,816
Depreciation and Amortization	29,275	26,322
Adjusted EBITDA	83,588	75,272
Operating lease right-of-use assets	111,213
Geographic divisions
Segment information
Net sales	840,157	771,550
Gross Profit	271,354	242,575
Depreciation and Amortization	28,934	25,855
Adjusted EBITDA	83,082	74,595
Operating lease right-of-use assets			$ 113,300
Other.
Segment information
Net sales	7,019	6,594
Gross Profit	2,300	2,241
Depreciation and Amortization	52	58
Adjusted EBITDA	506	677
Operating lease right-of-use assets			300
Corporate
Segment information
Depreciation and Amortization	$ 289	$ 409
Operating lease right-of-use assets			$ 5,200