Stockholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Jan. 31, 2023	Oct. 31, 2022	Jul. 31, 2022	Jan. 31, 2022	Oct. 31, 2021	Jul. 31, 2021	Jan. 31, 2023	Jan. 31, 2022
Beginning balance	$ 3,040	$ 2,807	$ 2,737	$ 2,923	$ 2,683	$ 2,656	$ 2,737	$ 2,656
Net income	100	227	249	259	236	192	576	687
Net other comprehensive income (loss)	91	2	1	(6)	2	8	94	4
Declaration of cash dividends	(197)		(180)	(659)		(172)
Stock-based compensation expense	4	5	4	4	3	4
Stock issued under compensation plans	1	1	4	2	1	5
Loss on issuance of treasury stock issued under compensation plans	(1)	(2)	(8)	(4)	(2)	(10)
Ending balance	3,038	3,040	2,807	2,519	2,923	2,683	3,038	2,519
Additional Paid-in Capital [Member]
Beginning balance	3	0	0	3	2	0	0	0
Stock-based compensation expense	4	5	4	4	3	4
Loss on issuance of treasury stock issued under compensation plans	(1)	(2)	(4)	(4)	(2)	(2)
Ending balance	6	3	0	3	3	2	6	3
Retained Earnings [Member]
Beginning balance	3,534	3,307	3,242	3,491	3,255	3,243	3,242	3,243
Net income	100	227	249	259	236	192
Declaration of cash dividends	(197)		(180)	(659)		(172)
Loss on issuance of treasury stock issued under compensation plans			(4)			(8)
Ending balance	3,437	3,534	3,307	3,091	3,491	3,255	3,437	3,091
AOCI Attributable to Parent [Member]
Beginning balance	(349)	(351)	(352)	(412)	(414)	(422)	(352)	(422)
Net other comprehensive income (loss)	91	2	1	(6)	2	8
Ending balance	(258)	(349)	(351)	(418)	(412)	(414)	(258)	(418)
Treasury Stock, Common [Member]
Beginning balance	(220)	(221)	(225)	(231)	(232)	(237)	(225)	(237)
Stock issued under compensation plans	1	1	4	2	1	5
Ending balance	(219)	(220)	(221)	(229)	(231)	(232)	(219)	(229)
Common stock, Class A, voting [Member] | Common Stock [Member]
Beginning balance	25	25	25	25	25	25	25	25
Ending balance	25	25	25	25	25	25	25	25
Common stock, Class B, nonvoting [Member] | Common Stock [Member]
Beginning balance	47	47	47	47	47	47	47	47
Ending balance	$ 47	$ 47	$ 47	$ 47	$ 47	$ 47	$ 47	$ 47