Restructuring Charges (Schedule Of Restructuring Activity And Related Reserves) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Apr. 28, 2013
2013 Initiatives [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Incurred Cost	$ 105
Cash Payments	(5)
Accrued Balance at end of period	17
2013 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Incurred Cost	22
Cash Payments	(5)
Accrued Balance at end of period	17
2013 Initiatives [Member] | Restructuring Charges Subtotal [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Incurred Cost	22
2013 Initiatives [Member] | Asset Impairment Accelerated Depreciation [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Incurred Cost	80
2013 Initiatives [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring and Related Cost, Incurred Cost	3
2011 Initiatives [Member]
Restructuring Reserve [Roll Forward]
Accrued Balance at beginning of period	16
Cash Payments	(9)
Accrued Balance at end of period	7
2011 Initiatives [Member] | Severance Pay And Benefits [Member]
Restructuring Reserve [Roll Forward]
Accrued Balance at beginning of period	14
Cash Payments	(9)
Accrued Balance at end of period	5
2011 Initiatives [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued Balance at beginning of period	2
Cash Payments
Accrued Balance at end of period	$ 2