Derivatives and Foreign Exchange Risk Management, Offsetting of Assets and Liabilities (Details) (USD $) In Millions, unless otherwise specified	Jan. 24, 2014	Apr. 26, 2013
Offsetting Assets and Liabilities [Line Items]
Derivative assets, gross amount	$ 263	$ 394
Gross amount not offset on the Balance Sheet, financial instruments	(102)	(58)
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	(30)
Derivative sssets, net amount	161	306
Derivative liabilities, gross amount	(111)	(58)
Gross amount not offset on the Balance Sheet, financial instruments	102	58
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	0
Derivative liabilities, net amount	(9)	0
Total derivatives, gross amount of recognized assets/(liabilities)	152	336
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	0	(30)
Total derivatives, net amount	152	306
Interest Rate Contracts
Offsetting Assets and Liabilities [Line Items]
Derivative assets, gross amount	107	181
Gross amount not offset on the Balance Sheet, financial instruments	(30)	(16)
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	(6)
Derivative sssets, net amount	77	159
Derivative liabilities, gross amount	(14)	(18)
Gross amount not offset on the Balance Sheet, financial instruments	14	18
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	0
Derivative liabilities, net amount	0	0
Foreign Currency Exchange Rate Contracts
Offsetting Assets and Liabilities [Line Items]
Derivative assets, gross amount	156	213
Gross amount not offset on the Balance Sheet, financial instruments	(72)	(42)
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	(24)
Derivative sssets, net amount	84	147
Derivative liabilities, gross amount	(97)	(40)
Gross amount not offset on the Balance Sheet, financial instruments	88	40
Gross amount not offset on the Balance Sheet, cash collateral (received) or pledged	0	0
Derivative liabilities, net amount	$ (9)	$ 0