Condensed Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2014	Oct. 31, 2013
Total revenue	$ 2,150,211	$ 2,015,885	$ 4,441,397	$ 4,130,634
Cost of goods sold (exclusive of depreciation and amortization, shown separately below)	1,778,929	1,696,600	3,699,201	3,468,928
Gross profit	371,282	319,285	742,196	661,706
Operating expenses	244,781	216,529	489,099	432,503
Depreciation and amortization	37,275	32,416	73,524	62,917
Interest, net	10,360	9,896	20,866	19,472
Income before income taxes	78,866	60,444	158,707	146,814
Federal and state income taxes	28,997	21,014	58,741	53,589
Net income	$ 49,869	$ 39,430	$ 99,966	$ 93,225
Net income per common share
Basic (in dollars per share)	$ 1.29	$ 1.03	$ 2.59	$ 2.43
Diluted (in dollars per share)	$ 1.28	$ 1.01	$ 2.56	$ 2.40
Basic weighted average shares outstanding (in shares)	38,706,611	38,455,216	38,668,453	38,424,146
Plus effect of stock compensation (in shares)	352,056	432,697	348,522	408,634
Diluted weighted average shares outstanding (in shares)	39,058,667	38,887,913	39,016,975	38,832,780