Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended
Jul. 31, 2020	Jul. 26, 2019	Apr. 24, 2020
Gain (Loss) on Securities [Line Items]
Debt securities in credit loss position	$ 0		$ 0
Reductions for available-for-sale securities sold	0	$ 0
Equity Securities and Other Investments
Gain (Loss) on Securities [Line Items]
Net gains (losses) recognized	12,000,000	0
Net realized gains (losses) on equity and other investments sold during the period		0
Net unrealized gains (losses) on equity and other investments still held	$ 12,000,000	$ 0

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 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).

+ References

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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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