Leases - Lease Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 23, 2021	Jan. 25, 2020	Jan. 23, 2021	Jan. 25, 2020
Leases [Abstract]
Operating lease expense	$ 103	$ 101	$ 201	$ 214
Short-term lease expense	17	16	35	33
Variable lease expense	43	39	89	79
Total lease expense	$ 163	$ 156	$ 325	$ 326