Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Income Statement [Abstract]
Total revenue	[1]	$ 2,487,586	$ 2,538,005	$ 5,114,215	$ 5,126,437
Cost of goods sold (exclusive of depreciation and amortization, shown separately below)	[1]	1,930,521	2,027,684	3,991,464	4,094,348
Operating expenses		373,383	344,186	753,224	703,578
Depreciation and amortization		62,888	61,356	122,696	120,196
Interest, net		12,683	14,191	26,404	28,597
Income before income taxes		108,111	90,588	220,427	179,718
Federal and state income taxes		26,130	23,973	52,631	42,879
Net income		$ 81,981	$ 66,615	$ 167,796	$ 136,839
Net income per common share
Basic (in dollars per share)		$ 2.22	$ 1.82	$ 4.55	$ 3.73
Diluted (in dollars per share)		$ 2.21	$ 1.80	$ 4.52	$ 3.70
Basic weighted average shares outstanding (in shares)		36,916,937	36,698,528	36,891,324	36,683,450
Plus effect of stock compensation (in shares)		219,248	318,943	218,189	314,181
Diluted weighted average shares outstanding (in shares)		37,136,185	37,017,471	37,109,513	36,997,631
Dividends declared per share (in dollars per share)		$ 0.32	$ 0.29	$ 0.64	$ 0.58
Excise taxes		$ 289,109	$ 255,114	$ 563,726	$ 513,083

[1] Includes excise taxes of: $289,109, $255,114, $563,726, and $513,083