Stockholders' Equity - Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 27, 2017	Jan. 29, 2016	Jan. 27, 2017	Jan. 29, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating expenses	$ 668	$ 690	$ 2,059	$ 2,271
Other income (expense), net	0	(2)	(1)	1
Net revenues	1,404	1,386	4,038	4,166
Total reclassifications	(5)	(2)	(5)	1
Reclassification out of Accumulated Other Comprehensive Income | Recognized Losses on Defined Benefit Obligations
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating expenses	0	0	1	2
Reclassification out of Accumulated Other Comprehensive Income | Realized Gains on Available-for-Sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	0	0	0	(1)
Reclassification out of Accumulated Other Comprehensive Income | Realized Gains on Cash Flow Hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net revenues	$ (5)	$ (2)	$ (6)	$ 0