Stock Purchase and Award Plans - Stock-based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
Apr. 24, 2020	Apr. 26, 2019	Apr. 27, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 297	$ 290	$ 344
Income tax benefits	(51)	(54)	(82)
Total stock-based compensation expense, net of tax	246	236	262
Cost of products sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	28	30	44
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	36	36	38
Selling, general, and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	233	224	262
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	61	72	132
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	205	189	185
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 31	$ 29	$ 27

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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