Restructuring and Other Charges (Schedule of Activities Related to Restructuring and Other Charges) (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 27, 2018	Oct. 28, 2017
Restructuring Reserve [Roll Forward]
Liability as of beginning period	$ 73	$ 117
Charges	78	152
Cash payments	(64)	(95)
Non-cash items	(23)	(6)
Liability as of ending period	64	168
FISCAL 2017 AND PRIOR PLANS | Employee Severance
Restructuring Reserve [Roll Forward]
Liability as of beginning period	41	74
Charges	0	145
Cash payments	(10)	(79)
Non-cash items	0	0
Liability as of ending period	31	140
FISCAL 2017 AND PRIOR PLANS | Other
Restructuring Reserve [Roll Forward]
Liability as of beginning period	13	43
Charges	0	7
Cash payments	(1)	(16)
Non-cash items	0	(6)
Liability as of ending period	12	$ 28
FISCAL 2018 PLAN | Employee Severance
Restructuring Reserve [Roll Forward]
Liability as of beginning period	19
Charges	54
Cash payments	(52)
Non-cash items	0
Liability as of ending period	21
FISCAL 2018 PLAN | Other
Restructuring Reserve [Roll Forward]
Liability as of beginning period	0
Charges	24
Cash payments	(1)
Non-cash items	(23)
Liability as of ending period	$ 0