Pension And Postretirement Benefits (Schedule Of Pension Plan Assets By Category) (Details) - Pension Plan, Defined Benefit [Member] - USD ($) $ in Millions		Jul. 29, 2018	Jul. 30, 2017	Jul. 31, 2016
Defined Benefit Plan, Fair Value of Plan Assets		$ 2,154	$ 2,183	$ 2,111
Defined Benefit Plan, Fair Value of Plan Assets Sub-Total		1,537	1,545
Alternative Investment, Fair Value Disclosure		631	666
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		547	673
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		950	827
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		40	45	51
Short-term Investments [Member]
Defined Benefit Plan, Fair Value of Plan Assets		61	46
Alternative Investment, Fair Value Disclosure		21	31
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		29	35
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		32	11
US Treasury and Government [Member]
Defined Benefit Plan, Fair Value of Plan Assets		70	60
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		70	60
Foreign Government Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		33	31
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		33	31
Municipal Bonds [Member]
Defined Benefit Plan, Fair Value of Plan Assets		61	58
Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		61	58
Asset-backed Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		15	8
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		15	8
Real Estate [Member]
Defined Benefit Plan, Fair Value of Plan Assets		10	17
Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		4	10
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		6	7	6
Hedge Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets		34	38
Alternative Investment, Fair Value Disclosure	[1]	95	103
Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		34	38	$ 45
Derivative Financial Instruments, Assets [Member]
Defined Benefit Plan, Fair Value of Plan Assets		8	9
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		8	9
Derivative Financial Instruments, Liabilities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		(4)	(10)
Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		(4)	(10)
Equity Funds [Member]
Alternative Investment, Fair Value Disclosure		310	332
Fixed Income Funds [Member]
Alternative Investment, Fair Value Disclosure		31	30
Blended Funds [Member]
Alternative Investment, Fair Value Disclosure		85	86
Real Estate Funds [Member]
Alternative Investment, Fair Value Disclosure		89	84
Other Items To Reconcile To Fair Value Of Plan Assets [Member]
Defined Benefit Plan, Fair Value of Plan Assets		(14)	(28)
UNITED STATES | Equity [Member]
Defined Benefit Plan, Fair Value of Plan Assets		284	338
UNITED STATES | Equity [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		284	338
UNITED STATES | Corporate Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		597	537
UNITED STATES | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		597	537
Non-U.S. [Member] | Equity [Member]
Defined Benefit Plan, Fair Value of Plan Assets		230	290
Non-U.S. [Member] | Equity [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		230	290
Non-U.S. [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		138	123
Non-U.S. [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		$ 138	$ 123

[1] Includes a fund valued at $2 in 2017 which was substantially liquidated in 2018.