Restructuring and Other Charges - Schedule of Activities Related to Restructuring and Other Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2020	Jul. 27, 2019	Jul. 28, 2018
Restructuring Reserve [Roll Forward]
Liability, beginning of period	$ 33	$ 73	$ 117
Charges	481	322	358
Cash payments	(327)	(299)	(372)
Non-cash items	(115)	(63)	(30)
Liability, end of period	72	33	73
FISCAL 2018 AND PRIOR PLANS | Employee Severance
Restructuring Reserve [Roll Forward]
Liability, beginning of period	22	60	74
Charges	209	252	319
Cash payments	(224)	(289)	(335)
Non-cash items	0	(1)	2
Liability, end of period	7	22	60
FISCAL 2018 AND PRIOR PLANS | Other
Restructuring Reserve [Roll Forward]
Liability, beginning of period	11	13	43
Charges	17	70	39
Cash payments	(3)	(10)	(37)
Non-cash items	(23)	(62)	(32)
Liability, end of period	2	11	13
FISCAL 2020 PLAN
Restructuring Reserve [Roll Forward]
Charges	255
FISCAL 2020 PLAN | Employee Severance
Restructuring Reserve [Roll Forward]
Liability, beginning of period	0	0	0
Charges	144	0	0
Cash payments	(93)	0	0
Non-cash items	0	0	0
Liability, end of period	51	0	0
FISCAL 2020 PLAN | Other
Restructuring Reserve [Roll Forward]
Liability, beginning of period	0	0	0
Charges	111	0	0
Cash payments	(7)	0	0
Non-cash items	(92)	0	0
Liability, end of period	$ 12	$ 0	$ 0