Financial Instruments , Activity Related to the Company's Debt Securities Portfolio and Available-for-sale Debt Securities Contractual Maturities (Details) - USD ($) $ in Millions	12 Months Ended
Apr. 26, 2019	Apr. 27, 2018	Apr. 28, 2017
AFS Gross Realized Gain (Loss)
Proceeds from sales	$ 3,718	$ 3,309	$ 3,646
Gross realized gains	18	27	49
Gross realized losses	(62)	(21)	$ (14)
AFS Debt Maturities
Due in one year or less	1,022
Due after one year through five years	2,198
Due after five years through ten years	2,244
Due after ten years	35
Total debt securities	$ 5,499	$ 6,820

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