Stock Purchase and Award Plans , Stock-based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
Apr. 26, 2019	Apr. 27, 2018	Apr. 28, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 290	$ 344	$ 348
Income tax benefits	(54)	(82)	(98)
Total stock-based compensation expense, net of tax	236	262	250
Cost of products sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	30	44	49
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	36	38	41
Selling, general, and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	224	262	256
Restructuring charges, net
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	0	0	2
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	72	132	157
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	189	185	169
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 29	$ 27	$ 22

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

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