Financing Arrangements (Details) (USD $) In Millions, unless otherwise specified																																												3 Months Ended	9 Months Ended		9 Months Ended
	Jan. 25, 2013	Apr. 27, 2012	Jan. 25, 2013 Senior Notes 2009 Due 2014	Jan. 25, 2013 Senior Notes 2010 Due 2015	Jan. 25, 2013 Senior Notes 2005 Due 2015	Jan. 25, 2013 Senior Notes 2011 Due 2016	Jan. 25, 2013 Senior Notes 2009 Due 2019	Jan. 25, 2013 Senior Notes 2010 Due 2020	Jan. 25, 2013 Senior Notes 2011 Due 2021	Jan. 25, 2013 Senior Notes 2012 Due 2022	Jan. 25, 2013 Senior Notes 2009 Due 2039	Jan. 25, 2013 Senior Notes 2010 Due 2040	Jan. 25, 2013 Senior Notes 2012 Due 2042	Jan. 25, 2013 2013 Senior Convertible Notes	Apr. 27, 2012 2013 Senior Convertible Notes	Jan. 27, 2012 2013 Senior Convertible Notes	Apr. 30, 2006 2013 Senior Convertible Notes	Jan. 25, 2013 Senior Notes Senior Notes 2009 Due 2014	Apr. 27, 2012 Senior Notes Senior Notes 2009 Due 2014	Jan. 25, 2013 Senior Notes Senior Notes 2010 Due 2015	Apr. 27, 2012 Senior Notes Senior Notes 2010 Due 2015	Jan. 25, 2013 Senior Notes Senior Notes 2005 Due 2015	Apr. 27, 2012 Senior Notes Senior Notes 2005 Due 2015	Jan. 25, 2013 Senior Notes Senior Notes 2011 Due 2016	Apr. 27, 2012 Senior Notes Senior Notes 2011 Due 2016	Jan. 25, 2013 Senior Notes Senior Notes 2009 Due 2019	Apr. 27, 2012 Senior Notes Senior Notes 2009 Due 2019	Jan. 25, 2013 Senior Notes Senior Notes 2010 Due 2020	Apr. 27, 2012 Senior Notes Senior Notes 2010 Due 2020	Jan. 25, 2013 Senior Notes Senior Notes 2011 Due 2021	Apr. 27, 2012 Senior Notes Senior Notes 2011 Due 2021	Jan. 25, 2013 Senior Notes Senior Notes 2012 Due 2022	Apr. 27, 2012 Senior Notes Senior Notes 2012 Due 2022	Jan. 25, 2013 Senior Notes Senior Notes 2009 Due 2039	Apr. 27, 2012 Senior Notes Senior Notes 2009 Due 2039	Jan. 25, 2013 Senior Notes Senior Notes 2010 Due 2040	Apr. 27, 2012 Senior Notes Senior Notes 2010 Due 2040	Jan. 25, 2013 Senior Notes Senior Notes 2012 Due 2042	Apr. 27, 2012 Senior Notes Senior Notes 2012 Due 2042	Jan. 25, 2013 Interest Rate Swap	Apr. 27, 2012 Interest Rate Swap	Jan. 25, 2013 Capital Lease Obligations	Apr. 27, 2012 Capital Lease Obligations	Jan. 25, 2013 Commercial Paper	Jan. 25, 2013 Commercial Paper	Apr. 27, 2012 Commercial Paper	Jan. 25, 2013 Credit Facility extension	Jan. 25, 2013 Credit Facility Line of Credit Facility 2017	Jan. 25, 2013 Credit Facility Line of Credit Facility 2014
Line of Credit Facility
Short-term borrowings	$ 4,104	$ 3,274																																										$ 1,635	$ 1,635	$ 950
Maximum credit available																																												2,250	2,250			2,250	2,250
Maximum maturities																																													364 days
Weighted average original maturity																																												104 days	84 days
Weighted average interest rate																																												0.20%	0.18%
Additional borrowing capacity																																															750
Number of extenstions																																															2
Term of extension																																															1 year
General Disclosures
Long-term debt	7,314	7,359												2,180	2,110			550	550	1,250	1,250	600	600	500	500	400	400	1,250	1,250	500	500	675	675	300	300	500	500	400	400	168	167	155	165
Gains from interest rate swap terminations	66	102
Principal amount				$ 1,250	$ 600	$ 500			$ 500	$ 675				$ 2,200	$ 2,200	$ 2,200	$ 2,200
Stated interest rate			4.50%	3.00%	4.75%	2.625%	5.60%	4.45%	4.125%	3.125%	6.50%	5.55%	4.50%				1.625%