Leases - Additional Information (Details) $ in Millions	12 Months Ended
	Jul. 25, 2020 USD ($)
Leases [Abstract]
Operating lease right-of-use assets	$ 921
Operating lease, right-of-use asset, statement of financial position [Extensible List]	us-gaap:OtherAssets
Operating lease liabilities	$ 1,002
Operating lease liabilities, current	$ 341
Operating lease, liability, current, statement of financial position [Extensible List]	us-gaap:OtherLiabilitiesCurrent
Operating lease liabilities, noncurrent	$ 661
Operating lease, liability, noncurrent, statement of financial position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Weighted-average remaining lease term (in years)	4 years
Weighted-average discount rate	1.50%
Sales-type lease term, on average	4 years
Interest income, lease receivables	$ 94
Operating lease income	$ 190