Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Oct. 31, 2018	Oct. 31, 2017
Income Statement [Abstract]
Net sales	$ 424,878	$ 274,769		$ 853,840	$ 551,596
Cost of sales and distribution	338,116	217,434		671,342	435,767
Gross Profit	86,762	57,335		182,498	115,829
Selling and marketing expenses	22,986		$ 18,077	45,924	36,230
General and administrative expenses	28,718	8,443		58,548	17,957
Restructuring charges, net	(406)			2,035	0
Operating Income	35,464		30,815	75,991	61,642
Interest expense (income), net	8,943	(631)		18,368	(1,148)
Other income	1,112		(17)	(325)	(45)
Income Before Income Taxes	25,409	31,463		57,948	62,835
Income tax expense	6,921	11,708		14,693	20,799
Net Income	$ 18,488	$ 19,755	$ 22,281	$ 43,255	$ 42,036
Weighted Average Shares Outstanding
Basic (in shares)	17,555,584	16,197,088		17,544,849	16,234,746
Diluted (in shares)	17,588,449	16,268,078		17,589,767	16,319,224
Net earnings per share
Basic (in usd per share)	$ 1.05	$ 1.22		$ 2.47	$ 2.59
Diluted (in usd per share)	$ 1.05	$ 1.21		$ 2.46	$ 2.58