Restructuring And Other Charges (Schedule Of Activity Related To Restructuring And Other Charges) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jan. 28, 2012	Jul. 30, 2011	Jul. 31, 2010
Restructuring Cost and Reserve [Line Items]
Beginning balance	$ 262
Charges	205		799
Cash payments	(376)	(449)
Non-cash items	(16)	(88)
Ending balance	75	262
Voluntary Early Retirement Program [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	17
Charges			453
Cash payments	(17)	(436)
Ending balance		17
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	234
Charges	179		247
Cash payments	(350)	(13)
Ending balance	63	234
Goodwill And Intangible Assets [Member]
Restructuring Cost and Reserve [Line Items]
Charges			71
Non-cash items		(71)
Other [Member]
Restructuring Cost and Reserve [Line Items]
Beginning balance	11
Charges	26		28
Cash payments	(9)
Non-cash items	(16)	(17)
Ending balance	$ 12	$ 11