Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	12 Months Ended
	Apr. 24, 2015	Apr. 25, 2014	Apr. 26, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period	$ (597)	$ (492)	$ (473)
Other comprehensive (loss) income before reclassifications, before tax	(398)	(136)
Tax benefit (expense)	(61)	39
Other comprehensive (loss) income before reclassifications, net of tax	(459)	(97)
Reclassifications, before tax	(205)	(15)
Tax benefit (expense)	77	7
Reclassifications, net of tax	(128)	(8)
Other comprehensive loss	(587)	(105)	(19)
Accumulated other comprehensive loss, end of period	(1,184)	(597)	(492)
Unrealized Gain (Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period	(6)	97
Other comprehensive (loss) income before reclassifications, before tax	169	(89)
Tax benefit (expense)	(60)	32
Other comprehensive (loss) income before reclassifications, net of tax	109	(57)
Reclassifications, before tax	(138)	(72)
Tax benefit (expense)	49	26
Reclassifications, net of tax	(89)	(46)
Other comprehensive loss	20	(103)
Accumulated other comprehensive loss, end of period	14	(6)	97
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period	218	205
Other comprehensive (loss) income before reclassifications, before tax	(495)	13
Tax benefit (expense)	0	0
Other comprehensive (loss) income before reclassifications, net of tax	(495)	13
Reclassifications, before tax	0	0
Tax benefit (expense)	0	0
Reclassifications, net of tax	0	0
Other comprehensive loss	(495)	13
Accumulated other comprehensive loss, end of period	(277)	218	205
Net Change in Retirement Obligations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period	(765)	(852)
Other comprehensive (loss) income before reclassifications, before tax	(617)	60
Tax benefit (expense)	198	(37)
Other comprehensive (loss) income before reclassifications, net of tax	(419)	23
Reclassifications, before tax	78	99
Tax benefit (expense)	(25)	(35)
Reclassifications, net of tax	53	64
Other comprehensive loss	(366)	87
Accumulated other comprehensive loss, end of period	(1,131)	(765)	(852)
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period	(44)	58
Other comprehensive (loss) income before reclassifications, before tax	545	(120)
Tax benefit (expense)	(199)	44
Other comprehensive (loss) income before reclassifications, net of tax	346	(76)
Reclassifications, before tax	(145)	(42)
Tax benefit (expense)	53	16
Reclassifications, net of tax	(92)	(26)
Other comprehensive loss	254	(102)
Accumulated other comprehensive loss, end of period	$ 210	$ (44)	$ 58