Fair Value Measurements Fair Value Measurements (Assets Measured On Recurring Basis Unobservable Input Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended
	Nov. 01, 2020	Oct. 27, 2019	[1]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Level 3 investments at beginning of year	$ 2	$ 76
Fair Value, Level 3 investment gain (Loss) Included in Earnings	0	(4)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(1)	0
Fair Value, Level 3 investments at end of year	$ 1	$ 72

[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 Venture Partners, L.P. (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.