Stockholders' Equity (Details) - USD ($) $ in Millions		3 Months Ended
	May 01, 2019	Jul. 31, 2019	Jul. 31, 2018	May 01, 2018
Beginning balance	$ 1,647	$ 1,647	$ 1,316
Cumulative effect of changes in accounting standards				$ (5)
Adoption of ASU 2018-02 (Note 1)	(43)
Net income		186	200
Net other comprehensive income (loss)		(1)	14
Declaration of cash dividends		(158)	(152)
Acquisition of treasury stock		(1)	(6)
Stock-based compensation expense		3	5
Stock issued under compensation plans		16	9
Loss on issuance of treasury stock issued under compensation plans		(29)	(13)
Ending balance		1,663	1,368
Additional Paid-in Capital [Member]
Beginning balance	0	0	4
Stock-based compensation expense		3	5
Loss on issuance of treasury stock issued under compensation plans		(2)	(7)
Ending balance		1	2
Retained Earnings [Member]
Beginning balance	2,238	2,238	1,730
Cumulative effect of changes in accounting standards				$ (5)
Adoption of ASU 2018-02 (Note 1)	43
Net income		186	200
Declaration of cash dividends		(158)	(152)
Loss on issuance of treasury stock issued under compensation plans		(27)	(6)
Ending balance		2,282	1,767
AOCI Attributable to Parent [Member]
Beginning balance	(363)	(363)	(378)
Adoption of ASU 2018-02 (Note 1)	(43)
Net other comprehensive income (loss)		(1)	14
Ending balance		(407)	(364)
Treasury Stock, Common [Member]
Beginning balance	(300)	(300)	(112)
Acquisition of treasury stock		(1)	(6)
Stock issued under compensation plans		16	9
Ending balance		(285)	(109)
Common stock, Class A, voting [Member] | Common Stock [Member]
Beginning balance	25	25	25
Ending balance		25	25
Common stock, Class B, nonvoting [Member] | Common Stock [Member]
Beginning balance	$ 47	47	47
Ending balance		$ 47	$ 47