Stockholders' Equity - Stock-Based Compensation Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Apr. 28, 2017	Apr. 29, 2016	Apr. 24, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 195	$ 260	$ 259
Income tax benefit for stock-based compensation	41	53	57
Cost of Product Revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	4	5	6
Cost of Hardware Maintenance and Other Services Revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	13	19	16
Sales and Marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	84	110	116
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	59	84	84
General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 35	$ 42	$ 37