Pension And Postretirement Benefits (Schedule Of Pension Plan Assets By Category) (Details) - Pension Plan, Defined Benefit [Member] - USD ($) $ in Millions		Jul. 30, 2017	Jul. 31, 2016		Aug. 02, 2015
Defined Benefit Plan, Fair Value of Plan Assets		$ 2,183	$ 2,111		$ 2,316
Defined Benefit Plan, Fair Value of Plan Assets Sub-Total		1,545	1,447
Alternative Investments, Fair Value Disclosure		666	691
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		673	676
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		827	720
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		45	51		45
Short-term Investments [Member]
Defined Benefit Plan, Fair Value of Plan Assets		46	43
Alternative Investments, Fair Value Disclosure		31	20
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		35	41
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		11	2
US Treasury and Government [Member]
Defined Benefit Plan, Fair Value of Plan Assets		60	49
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		60	49
Foreign Government Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		31	29
Foreign Government Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		31	29
Municipal Bonds [Member]
Defined Benefit Plan, Fair Value of Plan Assets		58	67
Municipal Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		58	67
Asset-backed Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		8	7
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		8	7
Real Estate [Member]
Defined Benefit Plan, Fair Value of Plan Assets		17	19
Real Estate [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		10	13
Real Estate [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		7	6		6
Hedge Funds [Member]
Defined Benefit Plan, Fair Value of Plan Assets		38	45
Alternative Investments, Fair Value Disclosure	[1]	103	144
Hedge Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		38	45		$ 39
Derivative Financial Instruments, Assets [Member]
Defined Benefit Plan, Fair Value of Plan Assets		9	6
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		9	6
Derivative Financial Instruments, Liabilities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		(10)	(7)
Derivative Financial Instruments, Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		(10)	(7)
Equity Funds [Member]
Alternative Investments, Fair Value Disclosure		332	309
Fixed Income Funds [Member]
Alternative Investments, Fair Value Disclosure		30	31
Blended Funds [Member]
Alternative Investments, Fair Value Disclosure		86	79
Real Estate Funds [Member]
Alternative Investments, Fair Value Disclosure		84	108	[2]
Other Items To Reconcile To Fair Value Of Plan Assets [Member]
Defined Benefit Plan, Fair Value of Plan Assets		(28)	(27)
UNITED STATES | Equity [Member]
Defined Benefit Plan, Fair Value of Plan Assets		338	349
UNITED STATES | Equity [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		338	349
UNITED STATES | Corporate Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		537	469
UNITED STATES | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		537	469
Non-U.S. [Member] | Equity [Member]
Defined Benefit Plan, Fair Value of Plan Assets		290	273
Non-U.S. [Member] | Equity [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		290	273
Non-U.S. [Member] | Corporate Debt Securities [Member]
Defined Benefit Plan, Fair Value of Plan Assets		123	98
Non-U.S. [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Fair Value of Plan Assets		$ 123	$ 98

[1] Includes a fund valued at $2 in 2017 and $45 in 2016 which is being liquidated. Distributions from the fund will be received as the underlying investments are liquidated which is estimated to occur by December 31, 2017.

[2] Included real estate investments valued at $34 in 2016 for which a redemption queue was imposed by the investment manager increasing the redemption receipt period to up to 9 months after notice.