Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Oct. 25, 2013		Oct. 26, 2012	Oct. 25, 2013		Oct. 26, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period				$ (492)
Other comprehensive (loss) income before reclassifications, before tax				(138)
Tax benefit (expense)				70
Other comprehensive (loss) income before reclassifications, net of tax				(68)
Reclassifications, before tax				(9)
Tax benefit (expense)				2
Reclassifications, net of tax				(7)
Other comprehensive (loss) income, net of tax	9		31	(75)		(11)
Accumulated other comprehensive loss, end of period	(567)			(567)
Unrealized Gain (Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period				97
Other comprehensive (loss) income before reclassifications, before tax				(68)
Tax benefit (expense)				25
Other comprehensive (loss) income before reclassifications, net of tax				(43)
Reclassifications, before tax				(33)
Tax benefit (expense)				12
Reclassifications, net of tax				(21)	[1]
Other comprehensive (loss) income, net of tax				(64)
Accumulated other comprehensive loss, end of period	33			33
Cumulative Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period				205	[2]
Other comprehensive (loss) income before reclassifications, before tax				51	[2]
Tax benefit (expense)				0	[2]
Other comprehensive (loss) income before reclassifications, net of tax				51	[2]
Reclassifications, before tax				0	[2]
Tax benefit (expense)				0	[2]
Reclassifications, net of tax				0	[2]
Other comprehensive (loss) income, net of tax				51	[2]
Accumulated other comprehensive loss, end of period	256	[2]		256	[2]
Net Change in Retirement Obligations
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period				(852)
Other comprehensive (loss) income before reclassifications, before tax				0
Tax benefit (expense)				0
Other comprehensive (loss) income before reclassifications, net of tax				0
Reclassifications, before tax				46
Tax benefit (expense)				(17)
Reclassifications, net of tax				29	[3]
Other comprehensive (loss) income, net of tax				29
Accumulated other comprehensive loss, end of period	(823)			(823)
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning of period				58
Other comprehensive (loss) income before reclassifications, before tax				(121)
Tax benefit (expense)				45
Other comprehensive (loss) income before reclassifications, net of tax				(76)
Reclassifications, before tax				(22)
Tax benefit (expense)				7
Reclassifications, net of tax				(15)	[4]
Other comprehensive (loss) income, net of tax				(91)
Accumulated other comprehensive loss, end of period	$ (33)			$ (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).