Financial Instruments - Activity Related to the Company's Investment Portfolio and Debt Securities Contractual Maturities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 30, 2020	Oct. 25, 2019	Oct. 30, 2020	Oct. 25, 2019	Apr. 24, 2020
Activities Related to Debt Securities Portfolio
Proceeds from sales	$ 1,932	$ 1,691	$ 4,335	$ 3,258
Gross realized gains	3	4	8	8
Gross realized losses	(1)	$ (4)	(7)	$ (12)
Available-For-Sale
Due in one year or less	1,930		1,930
Due after one year through five years	3,315		3,315
Due after five years through ten years	1,695		1,695
Due after ten years	67		67
Total	7,007		7,007		$ 6,841
Held-To-Maturity
Due in one year or less	886		886
Due after one year through five years	0		0
Due after five years through ten years	0		0
Due after ten years	0		0
Total	$ 886		$ 886