Leases (Costs) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jan. 31, 2021	Jan. 26, 2020	Jan. 31, 2021	Jan. 26, 2020
Operating Lease, Cost		$ 20	$ 21	$ 40	$ 40
Finance lease, amortization of right-of-use assets		1	1	2	1
Short-term Lease, Cost		11	10	21	20
Variable Lease, Cost	[1]	46	43	92	86
Sublease Income		0	(2)	(1)	(2)
Lease, Cost, Total	[2]	$ 78	73	$ 154	145
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Lease, Cost, Total			$ 2		$ 4

[1] Includes labor and other overhead in our service contracts with embedded leases.

[2] Total lease cost of $2 and $4 for the three- and six-month periods ended January 26, 2020, respectively, related to discontinued operations.