Leases (Reported in Balance Sheet) (Details) - USD ($) $ in Millions	Apr. 26, 2020	Jul. 28, 2019
Operating Lease, Right-of-Use Asset	$ 257
Finance Lease, Right-of-Use Asset	9
Operating Lease, Liability	253
Finance Lease, Liability, Noncurrent	7	$ 3
Finance Lease, Liability	10
Property, Plant and Equipment [Member]
Operating Lease, Right-of-Use Asset	0
Finance Lease, Right-of-Use Asset	9
Other Assets [Member]
Operating Lease, Right-of-Use Asset	257
Finance Lease, Right-of-Use Asset	0
Short-term Debt [Member]
Operating Lease, Liability, Current	0
Finance Lease, Liability, Current	3
Accrued Liabilities [Member]
Operating Lease, Liability, Current	66
Finance Lease, Liability, Current	0
Long-term Debt [Member]
Operating Lease, Liability, Noncurrent	0
Finance Lease, Liability, Noncurrent	7
Other Liabilities [Member]
Operating Lease, Liability, Noncurrent	187
Finance Lease, Liability, Noncurrent	$ 0