Stockholders' Equity - Stock-Based Compensation Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Apr. 29, 2016	Apr. 24, 2015	Apr. 25, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 260	$ 259	$ 273
Cost of Product Revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	5	6	5
Cost of Hardware Maintenance and Other Services Revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	19	16	17
Sales and Marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	110	116	125
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	84	84	88
General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 42	$ 37	$ 38