Derivatives and Foreign Exchange Risk Management, Balance Sheet Presentation (Details) (USD $) In Millions, unless otherwise specified	Jul. 27, 2012	Apr. 27, 2012
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 408	$ 254
Liability derivatives	143	82
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset derivatives	407	254
Liability derivatives	142	80
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	171	74
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	26	13
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	37	33
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Long-term Liabilities
Derivatives, Fair Value [Line Items]
Liability derivatives	11	2
Designated as Hedging Instrument | Interest Rate Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	210	167
Designated as Hedging Instrument | Interest Rate Contracts | Other Long-term Liabilities
Derivatives, Fair Value [Line Items]
Liability derivatives	94
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset derivatives	1	0
Liability derivatives	1	2
Not Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	1	0
Not Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	$ 1	$ 2