Derivatives and Foreign Exchange Risk Management, Freestanding Derivative Forward Contracts and Cash Flow Hedges (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended						3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Jan. 25, 2013	Apr. 27, 2012	Jan. 25, 2013 Foreign Currency Exchange Rate Contracts	Apr. 27, 2012 Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Interest Rate Swap	Apr. 27, 2012 Interest Rate Swap	Jan. 25, 2013 Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Cash Flow Hedging	Jan. 27, 2012 Cash Flow Hedging	Jan. 25, 2013 Cash Flow Hedging	Jan. 27, 2012 Cash Flow Hedging	Jan. 25, 2013 Cash Flow Hedging Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Cash Flow Hedging Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Cash Flow Hedging Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Cash Flow Hedging Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Cash Flow Hedging Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Cash Flow Hedging Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Cash Flow Hedging Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Cash Flow Hedging Other Expense, Net Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Cash Flow Hedging Cost of Products Sold Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Cash Flow Hedging Cost of Products Sold Foreign Currency Exchange Rate Contracts	Jan. 25, 2013 Cash Flow Hedging Cost of Products Sold Foreign Currency Exchange Rate Contracts	Jan. 27, 2012 Cash Flow Hedging Cost of Products Sold Foreign Currency Exchange Rate Contracts
Freestanding Derivative Forward Contracts
Notional amount of foreign currency derivatives not designated as hedging instruments	$ 1,662	$ 2,039
Gain (loss) on foreign currency derivatives not designated as hedging instruments							(4)	46	(24)	66
Cash Flow Hedges
Notional amount of cash flow hedge instruments			4,948	3,097
Maximum remaining maturity of foreign currency derivatives													3 years
Gains/(losses) recognized in OCI on effective portion of derivative											(20)	201	(21)	332	(20)	201	(21)	332
Effective portion of gains/(losses) on derivative reclassified from AOCI into income											26	(25)	69	(119)					22	(24)	64	(133)	4	(1)	5	14
Notional amount of interest rate cash flow hedge					1,250
Weighted average fixed rate of interest rate derivatives					2.78%
Unrealized losses associated with cash flow hedging instruments					74	45
After-tax net unrealized (losses)/gains associated with cash flow hedging instruments recorded in AOCI	(26)	6
Cash flow hedge unrealized gains to be reclassified over the next 12 months	$ 7