Leases (Supplemental Cash Flow Information) (Details) - USD ($) $ in Millions	6 Months Ended
	Jan. 31, 2021	Jan. 26, 2020
Leases [Abstract]
Operating Lease, Payments	$ 40	$ 38
Finance Lease, Principal Payments	2	0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	27	63
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	3	3
Operating Lease, Right-of-Use Asset divested with businesses sold	0	18
Finance Leases, Right-of-Use Asset divested with businesses sold	$ 0	$ 5