Comprehensive Income and Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Jan. 27, 2012	Oct. 28, 2011	Jul. 29, 2011	Jan. 28, 2011	Jan. 27, 2012	Jan. 28, 2011	Apr. 29, 2011
Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss) Disclosure [Abstract]
Comprehensive income	$ 816			$ 1,096	$ 2,574	$ 2,402
AOCI
Unrealized Gain/(Loss) on Investments	94	244	301		94		196
Cumulative Translation Adjustments	275	360	457		275		443
Net Change in Retirement Obligations	(569)	(584)	(599)		(569)		(607)
Unrealized Gain/(Loss) on Derivatives	(76)	(177)	(244)		(76)		(257)
Accumulated Other Comprehensive Loss	(276)	(157)	(85)		(276)		(224)
Other Comprehensive Income (Loss)
Unrealized Gain/(Loss) on Investments	(150)	(57)	105
Cumulative Translation Adjustments	(85)	(97)	14
Net Change in Retirement Obligations	15	15	8
Unrealized Gain/(Loss) on Derivatives	101	67	13
Other Comprehensive Income (Loss)	(119)	(72)	139
Other Comprehensive Income (Loss), Tax
Tax expense on the unrealized gain on foreign exchange rate derivatives	59				106
Tax expense related to the net change in retirement obligations	(6)				(18)
Tax expense on the unrealized gain on investments	$ 89				$ 61