Fair Value Measurements (Fair Value Measurement Of Assets And Liabilities) (Details) - USD ($) $ in Millions		Jan. 26, 2025	Jul. 28, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value		$ 19	$ 11
Derivatives liabilities at fair value		6	16
Measured On Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value		20	12
Total liabilities at fair value		116	117
Measured On Recurring Basis [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value		2	1
Total liabilities at fair value		110	102
Measured On Recurring Basis [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value		15	6
Total liabilities at fair value		5	15
Measured On Recurring Basis [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value		3	5
Total liabilities at fair value		1	0
Measured On Recurring Basis [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[1]	3	2
Derivatives liabilities at fair value	[1]	1	0
Measured On Recurring Basis [Member] | Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[1]	3	2
Derivatives liabilities at fair value	[1]	1	0
Measured On Recurring Basis [Member] | Commodity Derivative Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[2]	12	6
Derivatives liabilities at fair value	[2]	5	16
Measured On Recurring Basis [Member] | Commodity Derivative Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[2]	1	0
Derivatives liabilities at fair value	[2]	0	1
Measured On Recurring Basis [Member] | Commodity Derivative Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[2]	8	1
Derivatives liabilities at fair value	[2]	4	15
Measured On Recurring Basis [Member] | Commodity Derivative Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[2]	3	5
Derivatives liabilities at fair value	[2]	1	0
Measured On Recurring Basis [Member] | Equity Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[3]	4	3
Measured On Recurring Basis [Member] | Equity Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets at fair value	[3]	4	3
Measured On Recurring Basis [Member] | Deferred Compensation Investment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	[4]	1	1
Measured On Recurring Basis [Member] | Deferred Compensation Investment [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments at fair value	[4]	1	1
Measured On Recurring Basis [Member] | Deferred Compensation Obligation [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation obligation	[4]	110	101
Measured On Recurring Basis [Member] | Deferred Compensation Obligation [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation obligation	[4]	$ 110	$ 101

[1] Based on observable market transactions of spot currency rates and forward rates.

[2] Level 1 and 2 are based on quoted futures exchanges and on observable prices of futures and options transactions in the marketplace. Level 3 is based on unobservable inputs in which there is little or no market data, which requires management’s own assumptions within an internally developed model.

[3] Based on equity index swap rates.

[4] Based on the fair value of the participants’ investments.