Derivatives and Currency Exchange Risk Management - Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Jul. 27, 2018	Apr. 27, 2018
Derivative assets:
Gross Amount of Recorded Assets (Liabilities)	$ 219	$ 118
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(72)	(71)
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	147	47
Derivative liabilities:
Gross Amount of Recorded Assets (Liabilities)	(92)	(258)
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	72	71
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	76
Net Amount	(20)	(111)
Total
Gross Amount of Recorded Assets (Liabilities)	127	(140)
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0	0
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	76
Net Amount	127	(64)
Currency exchange rate contracts
Derivative assets:
Gross Amount of Recorded Assets (Liabilities)	170	79
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(68)	(61)
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	102	18
Derivative liabilities:
Gross Amount of Recorded Assets (Liabilities)	(71)	(238)
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	61	61
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	74
Net Amount	(10)	(103)
Interest rate contracts
Derivative assets:
Gross Amount of Recorded Assets (Liabilities)	6	8
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(3)	(6)
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	3	2
Derivative liabilities:
Gross Amount of Recorded Assets (Liabilities)	(16)	(14)
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	10	6
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	2
Net Amount	(6)	(6)
Total return swaps
Derivative assets:
Gross Amount of Recorded Assets (Liabilities)	6	4
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0	0
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	6	4
Stock warrants
Derivative assets:
Gross Amount of Recorded Assets (Liabilities)	27	21
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	0	0
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	27	21
Cross currency interest rate contracts
Derivative assets:
Gross Amount of Recorded Assets (Liabilities)	10	6
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	(1)	(4)
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	9	2
Derivative liabilities:
Gross Amount of Recorded Assets (Liabilities)	(5)	(6)
Gross Amount Not Offset on the Balance Sheet, Financial Instruments	1	4
Gross Amount Not Offset on the Balance Sheet, Cash Collateral Posted (Received)	0	0
Gross Amount Not Offset on the Balance Sheet, Securities Collateral Posted (Received)	0	0
Net Amount	$ (4)	$ (2)