Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Income Statement [Abstract]
Total revenue	[1]	$ 2,054,603	$ 1,769,993	$ 6,302,087	$ 5,660,127
Cost of goods sold (exclusive of depreciation and amortization, shown separately below)	[1]	1,634,679	1,380,364	4,937,809	4,377,185
Operating expenses		323,041	292,321	967,237	879,738
Depreciation and amortization		57,042	51,152	163,568	145,682
Interest, net		13,470	10,559	37,821	31,174
Income before income taxes		26,371	35,597	195,652	226,348
Federal and state income taxes		(166,594)	12,762	(102,989)	78,941
Net income		$ 192,965	$ 22,835	$ 298,641	$ 147,407
Net income per common share
Basic (in dollars per share)		$ 5.13	$ 0.58	$ 7.87	$ 3.76
Diluted (in dollars per share)		$ 5.08	$ 0.58	$ 7.80	$ 3.72
Basic weighted average shares outstanding (in shares)		37,579,497	39,194,671	37,932,071	39,183,388
Plus effect of stock compensation (in shares)		372,643	463,445	369,842	466,380
Diluted weighted average shares outstanding (in shares)		37,952,140	39,658,116	38,301,913	39,649,768
Dividends declared per share (in dollars per share)		$ 0.26	$ 0.24	$ 0.78	$ 0.72
Excise taxes		$ 231,422	$ 209,420	$ 709,050	$ 657,590

[1] Includes excise taxes of: $231,422, $209,420, $709,050, and $657,590