Pension And Postretirement Benefits (Schedule Of Pension Plan Assets By Category) (Details) - Pension Plan, Defined Benefit [Member] - USD ($) $ in Millions	Jul. 28, 2019	Jul. 29, 2018	Jul. 30, 2017
Defined Benefit Plan, Plan Assets, Amount	$ 2,153	$ 2,154	$ 2,183
Alternative Investment	644	631
Defined Benefit Plan, Fair Value of Plan Assets Sub-Total	1,580	1,537
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Plan Assets, Amount	521	547
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	1,023	950
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Plan Assets, Amount	36	40	45
Short-term Investments [Member]
Defined Benefit Plan, Plan Assets, Amount	78	61
Alternative Investment	23	21
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Plan Assets, Amount	32	29
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	46	32
Equity Securities, US [Member]
Defined Benefit Plan, Plan Assets, Amount	267	284
Equity Securities, US [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Plan Assets, Amount	267	284
Equity Securities , Non-US [Member]
Defined Benefit Plan, Plan Assets, Amount	217	230
Equity Securities , Non-US [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Plan Assets, Amount	217	230
Corporate Bonds, US [Member]
Defined Benefit Plan, Plan Assets, Amount	635	597
Corporate Bonds, US [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	635	597
Corporate Bonds, Non-US [Member]
Defined Benefit Plan, Plan Assets, Amount	142	138
Corporate Bonds, Non-US [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	142	138
US Treasury and Government [Member]
Defined Benefit Plan, Plan Assets, Amount	73	70
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	73	70
Debt Security, Government, Non-US [Member]
Defined Benefit Plan, Plan Assets, Amount	29	33
Debt Security, Government, Non-US [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	29	33
Municipal Bonds [Member]
Defined Benefit Plan, Plan Assets, Amount	64	61
Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	64	61
Asset-backed Securities [Member]
Defined Benefit Plan, Plan Assets, Amount	36	15
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	36	15
Real Estate [Member]
Defined Benefit Plan, Plan Assets, Amount	9	10
Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Plan Assets, Amount	5	4
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Plan Assets, Amount	4	6	7
Hedge Funds [Member]
Defined Benefit Plan, Plan Assets, Amount	32	34
Alternative Investment	76	95
Hedge Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount
Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Plan Assets, Amount	32	34	$ 38
Derivative Financial Instruments, Assets [Member]
Defined Benefit Plan, Plan Assets, Amount	4	8
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	4	8
Derivative Financial Instruments, Liabilities [Member]
Defined Benefit Plan, Plan Assets, Amount	(6)	(4)
Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Plan Assets, Amount	(6)	(4)
Equity Funds [Member]
Alternative Investment	319	310
Fixed Income Funds [Member]
Alternative Investment	35	31
Blended Funds [Member]
Alternative Investment	84	85
Real Estate Funds [Member]
Alternative Investment	107	89
Other Items To Reconcile To Fair Value Of Plan Assets [Member]
Alternative Investment	$ (71)	$ (14)