Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Oct. 24, 2014		Oct. 25, 2013		Oct. 24, 2014		Oct. 25, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period					$ (597)		$ (492)
Other comprehensive income (loss) before reclassifications, before tax					211		(138)
Tax expense					(115)		70
Other comprehensive income (loss) before reclassifications, net of tax					96		(68)
Reclassifications, before tax					(6)		(9)
Tax benefit (expense)					1		2
Reclassifications, net of tax					(5)		(7)
Other comprehensive income (loss), net of tax	(18)		9		91		(75)
Accumulated other comprehensive loss, end of period	(506)		(567)		(506)		(567)
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 income (loss) before reclassifications, before tax					61		(68)
Tax expense					(22)		25
Other comprehensive income (loss) before reclassifications, net of tax					39		(43)
Reclassifications, before tax					(28)		(33)
Tax benefit (expense)					9		12
Reclassifications, net of tax					(19)	[1]	(21)	[1]
Other comprehensive income (loss), net of tax					20		(64)
Accumulated other comprehensive loss, end of period	14		33		14		33
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period					218	[2]	205	[2]
Other comprehensive income (loss) before reclassifications, before tax					(129)	[2]	57	[2]
Tax expense					0	[2]	0	[2]
Other comprehensive income (loss) before reclassifications, net of tax					(129)	[2]	57	[2]
Reclassifications, before tax					0	[2]	0	[2]
Tax benefit (expense)					0	[2]	0	[2]
Reclassifications, net of tax					0	[2]	0	[2]
Other comprehensive income (loss), net of tax					(129)	[2]	57	[2]
Accumulated other comprehensive loss, end of period	89	[2]	262	[2]	89	[2]	262	[2]
Net Change in Retirement Obligations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period					(765)		(852)
Other comprehensive income (loss) before reclassifications, before tax					16		(6)
Tax expense					0		0
Other comprehensive income (loss) before reclassifications, net of tax					16		(6)
Reclassifications, before tax					38		46
Tax benefit (expense)					(12)		(17)
Reclassifications, net of tax					26	[3]	29	[3]
Other comprehensive income (loss), net of tax					42		23
Accumulated other comprehensive loss, end of period	(723)		(829)		(723)		(829)
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period					(44)		58
Other comprehensive income (loss) before reclassifications, before tax					263		(121)
Tax expense					(93)		45
Other comprehensive income (loss) before reclassifications, net of tax					170		(76)
Reclassifications, before tax					(16)		(22)
Tax benefit (expense)					4		7
Reclassifications, net of tax					(12)	[4]	(15)	[4]
Other comprehensive income (loss), net of tax					158		(91)
Accumulated other comprehensive loss, end of period	$ 114		$ (33)		$ 114		$ (33)

[1] Represents net realized gains on sales of available-for-sale securities that were reclassified from AOCI to other expense, net (see Note 6).

[2] Taxes are not provided on CTA 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 17).

[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 9).