Restructuring Charges (Schedule Of Restructuring Activity And Related Reserves) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Jul. 31, 2011	Jul. 29, 2012	Jul. 31, 2011	Aug. 01, 2010
Restructuring Cost and Reserve [Line Items]
Accrued Balance at beginning of period		$ 39	$ 0
Charges		6	41
Cash Payments		(28)	(2)
Foreign Currency Translation Adjustment		(1)
Accrued Balance at end of period	39	16	39	0
Restructuring Charges	63	10	63	12
Severance Pay And Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Accrued Balance at beginning of period		35	0
Charges		4	37
Cash Payments		(24)	(2)
Foreign Currency Translation Adjustment		(1)
Accrued Balance at end of period	35	14	35
Other Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Accrued Balance at beginning of period		4	0
Charges		2	4
Cash Payments		(4)	0
Accrued Balance at end of period	4	2	4
Asset Impairment/Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Charges		1	22
Contract Termination, Charges Recorded Directly to the Income Statement [Member]
Restructuring Cost and Reserve [Line Items]
Charges		$ 3	$ 0