Fair Value Measurements Fair Value Measurements (Assets Measured On Recurring Basis Unobservable Input Reconciliation) (Details) - USD ($) $ in Millions		12 Months Ended
		Aug. 01, 2021	Aug. 02, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs, Beginning Balance	[1]	$ 2	$ 76
Fair Value, Level 3 investment Gain (Loss) Included in Earnings		6	(45)	[1]
Fair Value, Level 3 investment Purchases		0	1	[1]
Fair Value, Level 3 Sales		0	(29)	[1]
Fair Value, Level 3 Settlements		(7)	(1)	[1]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs, Ending Balance		$ 1	$ 2	[1]

[1] Primarily represented investments in equity securities that were not readily marketable and were accounted for under the fair value option. The investments were funded by Acre, a limited partnership in which we were the sole limited partner. Fair value was based on analyzing recent transactions and transactions of comparable companies, and the discounted cash flow method. In addition, allocation methods, including the option pricing method, were used in distributing fair value among various equity holders according to rights and preferences. We entered into an agreement to sell our interest in Acre on April 26, 2020, and completed the sale on May 8, 2020. See Note 14 for additional information.