Stockholders' Equity - Accumulated Other Comprehensive Income (Loss) by Component Net of Tax (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Oct. 28, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 2,780
Other comprehensive income, net of tax	$ (6)	$ (10)	10	$ (10)
Ending balance	2,777		2,777
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(29)
Other comprehensive income, net of tax			8
Ending balance	(21)		(21)
Unrealized Gains (Losses) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			0
Other comprehensive income, net of tax			2
Ending balance	2		2
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(29)
Other comprehensive income, net of tax			10
Ending balance	$ (19)		$ (19)