Derivatives and Foreign Exchange Risk Management, Schedule of Derivative Instruments in Statement of Financial Position, Fair Value (Details) (USD $) In Millions, unless otherwise specified	Jan. 23, 2015	Apr. 25, 2014
Derivatives, Fair Value [Line Items]
Asset derivatives	$ 578	$ 175
Liability derivatives	105	127
Interest Rate Contracts
Derivatives, Fair Value [Line Items]
Asset derivatives	96	86
Liability derivatives	73	11
Foreign Currency Exchange Rate Contracts
Derivatives, Fair Value [Line Items]
Asset derivatives	482	89
Liability derivatives	32	116
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset derivatives	577	175
Liability derivatives	104	125
Designated as Hedging Instrument | Interest Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	12	13
Designated as Hedging Instrument | Interest Rate Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	84	73
Designated as Hedging Instrument | Interest Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	0	0
Designated as Hedging Instrument | Interest Rate Contracts | Other Long-term Liabilities
Derivatives, Fair Value [Line Items]
Liability derivatives	73	11
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	304	81
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Assets
Derivatives, Fair Value [Line Items]
Asset derivatives	177	8
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Accrued Expenses
Derivatives, Fair Value [Line Items]
Liability derivatives	30	84
Designated as Hedging Instrument | Foreign Currency Exchange Rate Contracts | Other Long-term Liabilities
Derivatives, Fair Value [Line Items]
Liability derivatives	1	30
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