Leases - Lease Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 01, 2021	Apr. 25, 2020	May 01, 2021	Apr. 25, 2020
Leases [Abstract]
Operating lease expense	$ 105	$ 101	$ 306	$ 315
Short-term lease expense	14	18	49	51
Variable lease expense	42	37	131	116
Total lease expense	$ 161	$ 156	$ 486	$ 482