Derivatives and Foreign Exchange Risk Management, Offsetting of Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Oct. 24, 2014	Apr. 25, 2014
Offsetting Assets and Liabilities [Line Items]
Derivative assets, gross amount	$ 350	$ 175
Gross amount not offset on the Balance Sheet, financial instruments	(55)	(95)
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	(80)	0
Derivative sssets, net amount	215	80
Derivative liabilities, gross amount	(57)	(127)
Gross amount not offset on the Balance Sheet, financial instruments	55	95
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	0
Derivative liabilities, net amount	(2)	(32)
Total derivatives, gross amount of recognized assets/(liabilities)	293	48
Total gross amount not offset on the Balance Sheet, financial instruments	0	0
Total gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	(80)	0
Total derivatives, net amount	213	48
Interest Rate Contracts
Offsetting Assets and Liabilities [Line Items]
Derivative assets, gross amount	90	86
Gross amount not offset on the Balance Sheet, financial instruments	(17)	(31)
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	(5)	0
Derivative sssets, net amount	68	55
Derivative liabilities, gross amount	(30)	(11)
Gross amount not offset on the Balance Sheet, financial instruments	28	11
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	0
Derivative liabilities, net amount	(2)	0
Foreign Currency Exchange Rate Contracts
Offsetting Assets and Liabilities [Line Items]
Derivative assets, gross amount	260	89
Gross amount not offset on the Balance Sheet, financial instruments	(38)	(64)
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	(75)	0
Derivative sssets, net amount	147	25
Derivative liabilities, gross amount	(27)	(116)
Gross amount not offset on the Balance Sheet, financial instruments	27	84
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	0
Derivative liabilities, net amount	$ 0	$ (32)