Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Jan. 31, 2019	Jan. 31, 2018
Income Statement [Abstract]
Sales	$ 1,181			$ 1,156			$ 3,329	$ 3,251
Excise taxes	277			278			749	736
Net sales	904			878			2,580	2,515
Cost of sales	333			291			896	825
Gross profit	571			587			1,684	1,690
Advertising expenses	103			112			303	308
Selling, general, and administrative expenses	149			173			478	496
Other expense (income), net	(1)			(4)			(13)	(15)
Operating income	320			306			916	901
Non-operating postretirement expense	15			2			19	7
Interest income	(2)			(2)			(6)	(4)
Interest expense	23			17			67	49
Income before income taxes	284			289			836	849
Income taxes	57			99			160	242
Net income	$ 227	$ 249	$ 200	$ 190	$ 239	$ 178	$ 676	$ 607
Earnings per share:
Basic (dollars per share)	$ 0.47			$ 0.39			$ 1.41	$ 1.26
Diluted (dollars per share)	$ 0.47			$ 0.39			$ 1.40	$ 1.25