Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2015	Oct. 31, 2014
Income Statement [Abstract]
Net sales	$ 256,292	$ 217,693	$ 487,490	$ 429,610
Cost of sales and distribution	200,240	180,712	381,265	355,515
Gross Profit	56,052	36,981	106,225	74,095
Selling and marketing expenses	16,783	16,296	32,502	31,811
General and administrative expenses	10,733	8,245	21,464	16,656
Restructuring charges, net	0	0	0	3
Operating Income	28,536	12,440	52,259	25,625
Interest expense	57	150	111	314
Other income	(54)	(32)	(106)	(65)
Income Before Income Taxes	28,533	12,322	52,254	25,376
Income tax expense	10,353	4,651	18,916	8,467
Net Income	$ 18,180	$ 7,671	$ 33,338	$ 16,909
Weighted Average Shares Outstanding
Basic (in shares)	16,282,881	15,672,198	16,231,870	15,602,150
Diluted (in shares)	16,472,645	15,960,236	16,446,937	15,864,560
Net earnings per share
Basic (in usd per share)	$ 1.12	$ 0.49	$ 2.05	$ 1.08
Diluted (in usd per share)	$ 1.10	$ 0.48	$ 2.03	$ 1.07