Revenue - Allowance for Accounts Receivable (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 30, 2021	Oct. 24, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss at beginning of period	$ 109	$ 143
Provisions (benefits)	19	14
Recoveries (write-offs), net	(14)	(6)
Foreign exchange and other	0	(26)
Allowance for credit loss at end of period	$ 114	$ 125