Stockholders' Equity - Accumulated Other Comprehensive Income (Loss) by Component Net of Tax (Detail) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2015	Jul. 25, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (24)
OCI before reclassifications, net of tax	(12)
Amounts reclassified from AOCI, net of tax	2
Other comprehensive income (loss)	(10)	$ 0
Ending balance	(34)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(23)
OCI before reclassifications, net of tax	(1)
Amounts reclassified from AOCI, net of tax	0
Other comprehensive income (loss)	(1)
Ending balance	(24)
Defined Benefit Obligation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(13)
Amounts reclassified from AOCI, net of tax	1
Other comprehensive income (loss)	1
Ending balance	(12)
Unrealized Gains on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	11
OCI before reclassifications, net of tax	(9)
Amounts reclassified from AOCI, net of tax	0
Other comprehensive income (loss)	(9)
Ending balance	2
Unrealized Gains (Losses) on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	1
OCI before reclassifications, net of tax	(2)
Amounts reclassified from AOCI, net of tax	1
Other comprehensive income (loss)	$ (1)