Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Income Statement [Abstract]
Total revenue	[1]	$ 2,048,076	$ 2,054,603	$ 7,174,513	$ 6,302,087
Cost of goods sold (exclusive of depreciation and amortization, shown separately below)	[1]	1,577,811	1,634,679	5,672,159	4,937,809
Operating expenses		341,536	323,041	1,045,114	967,237
Depreciation and amortization		61,324	57,042	181,520	163,568
Interest, net		13,310	13,470	41,907	37,821
Income before income taxes		54,095	26,371	233,813	195,652
Federal and state income taxes		12,260	(166,594)	55,139	(102,989)
Net income		$ 41,835	$ 192,965	$ 178,674	$ 298,641
Net income per common share
Basic (in dollars per share)		$ 1.14	$ 5.13	$ 4.87	$ 7.87
Diluted (in dollars per share)		$ 1.13	$ 5.08	$ 4.83	$ 7.80
Basic weighted average shares outstanding (in shares)		36,717,415	37,579,497	36,694,308	37,932,071
Plus effect of stock compensation (in shares)		296,411	372,643	291,783	369,842
Diluted weighted average shares outstanding (in shares)		37,013,826	37,952,140	36,986,091	38,301,913
Dividends declared per share (in dollars per share)		$ 0.29	$ 0.26	$ 0.87	$ 0.78
Excise taxes		$ 238,306	$ 231,422	$ 751,389	$ 709,050

[1] Includes excise taxes of: $238,306, $231,422, $751,389 and $709,050