Pension And Postretirement Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 29, 2012	May 01, 2011	Apr. 29, 2012	May 01, 2011
Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 14	$ 15	$ 41	$ 44
Interest cost	31	30	92	91
Expected return on plan assets	(44)	(45)	(133)	(134)
Recognized net actuarial loss	18	17	55	52
Net periodic benefit expense	19	17	55	53
Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	2	2
Interest cost	4	5	13	14
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	0	0	(1)	(1)
Recognized net actuarial loss	3	2	7	6
Net periodic benefit expense	7	7	21	21
United States Pension Plans of US Entity, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer			55
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	0		0
Foreign Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer			13
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 3		$ 3