Restructuring and Other Charges (Schedule Of Activities Related To Restructuring And Other Charges) (Details) - USD ($) $ in Millions	6 Months Ended
	Jan. 28, 2017	Jan. 23, 2016
Restructuring Reserve [Roll Forward]
Liability as of beginning period	$ 45	$ 89
Charges	544	238
Cash payments	(388)	(197)
Non-cash items	(73)	(21)
Liability as of ending period	128	109
FISCAL 2015 AND PRIOR PLANS | Employee Severance
Restructuring Reserve [Roll Forward]
Liability as of beginning period	21	60
Charges	0	206
Cash payments	(13)	(187)
Non-cash items	(4)	0
Liability as of ending period	4	79
FISCAL 2015 AND PRIOR PLANS | Other
Restructuring Reserve [Roll Forward]
Liability as of beginning period	24	29
Charges	0	32
Cash payments	(4)	(10)
Non-cash items	(9)	(21)
Liability as of ending period	11	$ 30
FISCAL 2017 PLAN | Employee Severance
Restructuring Reserve [Roll Forward]
Liability as of beginning period	0
Charges	452
Cash payments	(368)
Non-cash items	(2)
Liability as of ending period	82
FISCAL 2017 PLAN | Other
Restructuring Reserve [Roll Forward]
Liability as of beginning period	0
Charges	92
Cash payments	(3)
Non-cash items	(58)
Liability as of ending period	$ 31