Derivatives and Foreign Exchange Risk Management, Balance Sheet Presentation (Details) (USD $) In Millions, unless otherwise specified	Jul. 25, 2014	Apr. 25, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 176	$ 175
Liability derivatives	68	127
Foreign Currency Exchange Rate Contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	96	89
Liability derivatives	68	116
Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	80	86
Liability derivatives		11
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	175	175
Liability derivatives	67	125
Designated as Hedging Instrument [Member] | Foreign Currency Exchange Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	72	81
Designated as Hedging Instrument [Member] | Foreign Currency Exchange Rate Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	23	8
Designated as Hedging Instrument [Member] | Foreign Currency Exchange Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	52	84
Designated as Hedging Instrument [Member] | Foreign Currency Exchange Rate Contracts | Other Long-term Liabilities
Derivatives, Fair Value [Line Items]
Liability derivatives	15	30
Designated as Hedging Instrument [Member] | Interest Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	9	13
Designated as Hedging Instrument [Member] | Interest Rate Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	71	73
Designated as Hedging Instrument [Member] | Interest Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	0	0
Designated as Hedging Instrument [Member] | Interest Rate Contracts | Other Long-term Liabilities
Derivatives, Fair Value [Line Items]
Liability derivatives	0	11
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	0
Liability derivatives	1	2
Not Designated as Hedging Instrument [Member] | Foreign Currency Exchange Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	0
Not Designated as Hedging Instrument [Member] | Foreign Currency Exchange Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	$ 1	$ 2