Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 01, 2021	Apr. 25, 2020	May 01, 2021	Apr. 25, 2020	Jul. 25, 2020
Leases [Abstract]
Weighted-average remaining lease term (in years)	4 years 1 month 6 days		4 years 1 month 6 days		4 years
Weighted-average discount rate	0.90%		0.90%		1.50%
Sales-type lease terms, on average	4 years		4 years
Interest income, lease receivables	$ 19	$ 23	$ 59	$ 72
Operating lease income	$ 36	$ 49	$ 119	$ 143