Financial Instruments , Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 26, 2019	Apr. 27, 2018	Apr. 28, 2017	Apr. 28, 2018		Apr. 29, 2017	[2]
Schedule of Investments [Line Items]
Credit loss portion of other-than-temporary impairments	$ 0	$ 0
Reductions for available-for-sale securities sold	0	0
Cumulative effect of change in accounting principle				$ 0	[1]	$ 296
Investment loss	0	227	$ 0
Carrying value of investments prior to recognizing impairment charges		317
Investment loss
Schedule of Investments [Line Items]
Investment loss		227
Equity Investments
Schedule of Investments [Line Items]
Net gains recognized	104
Net realized gains on equity and other investments sold during the period	94
Net unrealized gains on equity and other investments still held	10
Investment loss	$ 45	$ 231	$ 30
Accumulated Other Comprehensive Loss
Schedule of Investments [Line Items]
Cumulative effect of change in accounting principle				47	[1]	(203)
Accumulated Other Comprehensive Loss | Accounting Standards Update 2016-01
Schedule of Investments [Line Items]
Cumulative effect of change in accounting principle				47
Retained Earnings
Schedule of Investments [Line Items]
Cumulative effect of change in accounting principle				(47)	[1]	$ 499
Retained Earnings | Accounting Standards Update 2016-01
Schedule of Investments [Line Items]
Cumulative effect of change in accounting principle				$ (47)

[1] See Note 1 to the consolidated financial statements for discussion regarding the adoption of accounting standards during fiscal year 2019.

[2] The cumulative effect of change in accounting principle in fiscal year 2018 resulted from the adoption of accounting guidance that requires the tax effect of intra-entity transactions, other than sales of inventory, to be recognized when the transaction occurs, and accounting guidance which permitted reclassification of stranded tax effects resulting from the enactment of comprehensive U.S. tax legislation from accumulated other comprehensive loss to retained earnings.