Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Income Statement [Abstract]
Net sales	$ 218,632	$ 188,963	$ 706,122	$ 618,573
Cost of sales and distribution	174,034	153,846	555,299	509,361
Gross Profit	44,598	35,117	150,823	109,212
Selling and marketing expenses	16,674	16,010	49,176	47,821
General and administrative expenses	9,183	8,054	30,647	24,710
Restructuring charges, net	0	3	0	6
Operating Income	18,741	11,050	71,000	36,675
Interest expense	119	131	230	445
Other income	(61)	(57)	(167)	(122)
Income Before Income Taxes	18,683	10,976	70,937	36,352
Income tax expense	6,670	3,694	25,586	12,161
Net Income	$ 12,013	$ 7,282	$ 45,351	$ 24,191
Weighted Average Shares Outstanding
Basic (in shares)	16,294,889	15,859,533	16,252,876	15,687,944
Diluted (in shares)	16,457,308	16,131,140	16,450,394	15,953,420
Net earnings per share
Basic (in usd per share)	$ 0.74	$ 0.46	$ 2.79	$ 1.54
Diluted (in usd per share)	$ 0.73	$ 0.45	$ 2.76	$ 1.52