Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions		3 Months Ended
		Jul. 31, 2015	Jul. 25, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period		$ (1,184)	$ (597)
Other comprehensive (loss) income before reclassifications, before tax		(212)	167
Tax benefit (expense)		64	(58)
Other comprehensive (loss) income before reclassifications, net of tax		(148)	109
Reclassifications, before tax		(44)	1
Tax benefit (expense)		20	(1)
Reclassifications, net of tax		(24)	0
Other comprehensive (loss) income, net of tax		(172)	109
Accumulated other comprehensive loss, end of period		(1,356)	(488)
Unrealized Gain (Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period		14	(6)
Other comprehensive (loss) income before reclassifications, before tax		(193)	107
Tax benefit (expense)		70	(39)
Other comprehensive (loss) income before reclassifications, net of tax		(123)	68
Reclassifications, before tax		(12)	(21)
Tax benefit (expense)		4	7
Reclassifications, net of tax	[1]	(8)	(14)
Other comprehensive (loss) income, net of tax		(131)	54
Accumulated other comprehensive loss, end of period		(117)	48
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period	[2]	(277)	218
Other comprehensive (loss) income before reclassifications, before tax	[2]	(26)	1
Tax benefit (expense)	[2]	0	0
Other comprehensive (loss) income before reclassifications, net of tax	[2]	(26)	1
Reclassifications, before tax	[2]	0	0
Tax benefit (expense)	[2]	0	0
Reclassifications, net of tax	[2]	0	0
Other comprehensive (loss) income, net of tax	[2]	(26)	1
Accumulated other comprehensive loss, end of period	[2]	(303)	219
Net Change in Retirement Obligations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period		(1,131)	(765)
Other comprehensive (loss) income before reclassifications, before tax		(7)	4
Tax benefit (expense)		0	0
Other comprehensive (loss) income before reclassifications, net of tax		(7)	4
Reclassifications, before tax		30	19
Tax benefit (expense)		(10)	(6)
Reclassifications, net of tax	[3]	20	13
Other comprehensive (loss) income, net of tax		13	17
Accumulated other comprehensive loss, end of period		(1,118)	(748)
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period		210	(44)
Other comprehensive (loss) income before reclassifications, before tax		14	55
Tax benefit (expense)		(6)	(19)
Other comprehensive (loss) income before reclassifications, net of tax		8	36
Reclassifications, before tax		(62)	3
Tax benefit (expense)		26	(2)
Reclassifications, net of tax	[4]	(36)	1
Other comprehensive (loss) income, net of tax		(28)	37
Accumulated other comprehensive loss, end of period		$ 182	$ (7)

[1] Represents net realized gains on sales of available-for-sale securities that were reclassified from AOCI to other expense, net (see Note 5).

[2] Taxes are not provided on cumulative translation adjustments as substantially all translation adjustments relate to earnings that are intended to be indefinitely reinvested outside the U.S.

[3] Includes net amortization of prior service costs and actuarial losses included in net periodic benefit cost (see Note 14).

[4] Relates to foreign currency cash flow hedges that were reclassified from AOCI to other expense, net or cost of products sold and forward starting interest rate derivative instruments that were reclassified from AOCI to interest expense, net (see Note 8).