Restructuring and Other Charges (Schedule Of Activities Related To Restructuring And Other Charges) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Oct. 25, 2014
Restructuring Reserve [Roll Forward]
Liability as of beginning period	$ 69
Gross charges	318
Cash payments	(155)
Non-cash items	0
Liability as of ending period	232
Fiscal 2014 plan and prior plans | Employee Severance
Restructuring Reserve [Roll Forward]
Liability as of beginning period	40
Gross charges	0
Cash payments	(13)
Non-cash items	0
Liability as of ending period	27
Fiscal 2014 plan and prior plans | Other
Restructuring Reserve [Roll Forward]
Liability as of beginning period	29
Gross charges	0
Cash payments	0
Non-cash items	(4)
Liability as of ending period	25
Fiscal 2015 plan | Employee Severance
Restructuring Reserve [Roll Forward]
Liability as of beginning period	0
Gross charges	322
Cash payments	(142)
Non-cash items	0
Liability as of ending period	180
Fiscal 2015 plan | Other
Restructuring Reserve [Roll Forward]
Liability as of beginning period	0
Gross charges	(4)
Cash payments	0
Non-cash items	4
Liability as of ending period	$ 0