Segments - Net Sales, Adjusted EBITDA and Certain Other Measures (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019	May 01, 2019
Segment information
Net sales	$ 761,352	$ 723,902	$ 2,470,457	$ 2,335,883
Gross Profit	253,473	234,226	811,620	747,192
Depreciation and Amortization	29,422	30,220	88,215	87,329
Adjusted EBITDA	62,697	59,717	236,190	222,134
Operating lease right-of-use assets	118,092		118,092
Geographic divisions
Segment information
Net sales	754,916	717,984	2,449,926	2,316,732
Gross Profit	251,086	232,201	804,340	740,591
Depreciation and Amortization	28,791	29,368	86,747	85,284
Adjusted EBITDA	62,169	59,321	234,422	220,365
Operating lease right-of-use assets					$ 113,300
Other.
Segment information
Net sales	6,436	5,918	20,531	19,151
Gross Profit	2,387	2,025	7,280	6,601
Depreciation and Amortization	56	55	164	168
Adjusted EBITDA	528	396	1,768	1,769
Operating lease right-of-use assets					300
Corporate
Segment information
Depreciation and Amortization	$ 575	$ 797	$ 1,304	$ 1,877
Operating lease right-of-use assets					$ 5,200