CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2015	Jul. 25, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (30)	$ 88
Other comprehensive income (loss):
Foreign currency translation adjustments	(1)	(1)
Defined benefit obligations:
Defined benefit obligation adjustments	0	2
Reclassification adjustments related to defined benefit obligations	1	0
Unrealized losses on available-for-sale securities:
Unrealized holding losses arising during the period	(9)	(2)
Unrealized gains (losses) on cash flow hedges:
Unrealized holding losses arising during the period	(2)	(1)
Reclassification adjustments for losses included in net income (loss)	1	2
Other comprehensive income (loss)	(10)	0
Comprehensive income (loss)	$ (40)	$ 88