Restructuring Charges (Details) (Fiscal Year 2012 Initiative, USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended	12 Months Ended
	Jan. 25, 2013	Oct. 26, 2012	Jul. 27, 2012	Apr. 27, 2012 Positions	Jan. 25, 2013 Positions	Apr. 27, 2012
Changes in Restructuring Reserves
Beginning balance	$ 27	$ 48	$ 91		$ 91	$ 0
Restructuring charges				118		118
Payments/write-downs	(6)	(21)	(43)			(27)
Ending balance	21	27	48	91	21	91
Expected number of positions eliminated				1,000
Number of positions eliminated					600
Employee Termination Costs
Changes in Restructuring Reserves
Beginning balance	21	38	64		64	0
Restructuring charges				66		66
Payments/write-downs	(5)	(17)	(26)			(2)
Ending balance	16	21	38	64	16	64
Asset Write-downs
Changes in Restructuring Reserves
Beginning balance	0	0	0		0	0
Restructuring charges				9		9
Payments/write-downs	0	0	0			(9)
Ending balance	0	0	0	0	0	0
Contract Termination Costs
Changes in Restructuring Reserves
Restructuring charges				30
Other Related Cost
Changes in Restructuring Reserves
Beginning balance	6	10	27		27	0
Restructuring charges				13		43
Payments/write-downs	(1)	(4)	(17)			(16)
Ending balance	$ 5	$ 6	$ 10	$ 27	$ 5	$ 27