Derivatives and Foreign Exchange Risk Management - Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Jan. 29, 2016	Apr. 24, 2015
Offsetting Assets and Liabilities [Line Items]
Derivative Assets, Gross Amount of Recognized Assets (Liabilities)	$ 496	$ 733
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(69)	(71)
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	(212)	(338)
Derivative Assets, Net Amount	215	324
Derivative Liabilities, Gross Amount of Recognized Assets (Liabilities)	(91)	(116)
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	69	71
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	0	8
Derivative Liabilities, Net Amount	(22)	(37)
Gross Amount of Recognized Assets (Liabilities)	405	617
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0	0
Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	(212)	(330)
Net Amount	193	287
Foreign currency exchange rate contracts [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Assets, Gross Amount of Recognized Assets (Liabilities)	387	644
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(63)	(61)
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	(197)	(325)
Derivative Assets, Net Amount	127	258
Derivative Liabilities, Gross Amount of Recognized Assets (Liabilities)	(40)	(45)
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	33	31
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	0	0
Derivative Liabilities, Net Amount	(7)	(14)
Interest rate contracts [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Assets, Gross Amount of Recognized Assets (Liabilities)	88	89
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(6)	(10)
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	(15)	(13)
Derivative Assets, Net Amount	67	66
Derivative Liabilities, Gross Amount of Recognized Assets (Liabilities)	(41)	(71)
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	36	40
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	0	8
Derivative Liabilities, Net Amount	(5)	$ (23)
Cross currency interest rate contracts [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Assets, Gross Amount of Recognized Assets (Liabilities)	21
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0
Derivative Assets, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	0
Derivative Assets, Net Amount	21
Derivative Liabilities, Gross Amount of Recognized Assets (Liabilities)	(5)
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	0
Derivative Liabilities, Net Amount	(5)
Commodity derivatives [Member]
Offsetting Assets and Liabilities [Line Items]
Derivative Liabilities, Gross Amount of Recognized Assets (Liabilities)	(5)
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0
Derivative Liabilities, Gross Amount Not Offset on the Balance Sheet, Collateral (Received) or Posted	0
Derivative Liabilities, Net Amount	$ (5)