Financial Instruments - Additional Information (Details) - USD ($)	12 Months Ended
Apr. 24, 2020	Apr. 26, 2019	Apr. 27, 2018
Schedule of Investments [Line Items]
Credit loss portion of other-than-temporary impairments	$ 0	$ 0
Reductions for available-for-sale securities sold	0	0
Impairment charges recognized	0	0	$ 227,000,000
Carrying value of investments prior to recognizing impairment charges			317,000,000
Equity Investments
Schedule of Investments [Line Items]
Net gains (losses) recognized	(13,000,000)	104,000,000
Net unrealized gains (losses) on equity and other investments still held	(15,000,000)	10,000,000
Net realized gains on equity and other investments sold during the period	2,000,000	94,000,000
Impairment charges recognized	$ 4,000,000	$ 45,000,000	$ 231,000,000

Cost and Equity Method Investments, Carrying Value Before Realized Loss

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Amount of realized and unrealized gain (loss) on investment.

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The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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This item represents reductions in the cumulative amount of credit losses recognized in earnings for an other than temporary impairment (OTTI) of a debt security because of the sale of impaired securities during the period.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of unrealized gain (loss) on investment.

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