Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Income Statement [Abstract]
Total revenue	$ 7,767,216	$ 7,840,255	$ 7,250,840
Cost of goods sold (exclusive of depreciation and amortization, shown separately below)	6,327,431	6,618,239	6,179,771
Gross profit	1,439,785	1,222,016	1,071,069
Operating expenses	960,424	857,297	760,365
Depreciation and amortization	156,111	131,160	111,823
Interest, net	41,225	39,915	35,265
Income before income taxes	282,025	193,644	163,616
Federal and state income taxes	101,397	66,824	59,802
Net income	$ 180,628	$ 126,820	$ 103,814
Net income per common share
Basic (in Dollars per share)	$ 4.66	$ 3.30	$ 2.71
Diluted (in Dollars per share)	$ 4.62	$ 3.26	$ 2.69