Employee Benefit Plans - Summary of Restricted Stock and Stock Unit Activity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Oct. 26, 2019	Jul. 27, 2019
Restricted Stock/ Stock Units
Granted (in shares)	13,000,000	67,000,000
Restricted Stock/Stock Units
Restricted Stock/ Stock Units
Beginning balance (in shares)	100,000,000	119,000,000
Granted (in shares)	8,000,000	45,000,000
Vested (in shares)	(12,000,000)	(50,000,000)
Canceled/forfeited (in shares)	(3,000,000)	(14,000,000)
Ending balance (in shares)	93,000,000	100,000,000
Weighted-Average Grant Date Fair Value per Share
Beginning balance (in dollars per share)	$ 38.66	$ 30.56
Granted (in dollars per share)	44.56	47.71
Vested (in dollars per share)	29.71	29.25
Canceled/forfeited (in dollars per share)	38.57	32.01
Ending balance (in dollars per share)	$ 40.28	$ 38.66
Aggregate Fair Value	$ 551	$ 2,446