Goodwill and Other Intangible Assets, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 25, 2013	Jan. 27, 2012	Jan. 25, 2013	Jan. 27, 2012	Apr. 27, 2012
The changes in the carrying amount of goodwill
Beginning balance			$ 9,934
Goodwill as a result of acquisitions			413
Purchase accounting adjustments, net			1
Currency adjustments, net			(7)
Ending balance	10,341		10,341
Balance of intangible assets, excluding goodwill
Original cost	4,793		4,793		4,495
Accumulated amortization	(2,035)		(2,035)		(1,848)
Carrying value	2,758		2,758		2,647
Amortization expense	88	84	247	255
Estimated aggregate amortization expense
Remaining 2013	86		86
2014	337		337
2015	320		320
2016	307		307
2017	286		286
2018	270		270
Thereafter	786		786
Total estimated amortization expense	2,392		2,392
Purchased Technology and Patents
Balance of intangible assets, excluding goodwill
Original cost	3,898		3,898		3,604
Accumulated amortization	(1,626)		(1,626)		(1,440)
Carrying value	2,272		2,272		2,164
Trademarks and Tradenames
Balance of intangible assets, excluding goodwill
Original cost	408		408		373
Accumulated amortization	(317)		(317)		(307)
Carrying value	91		91		66
Acquired in Process Research and Development [Member]
Balance of intangible assets, excluding goodwill
Original cost	366		366		370
Accumulated amortization	0		0		0
Carrying value	366		366		370
Other
Balance of intangible assets, excluding goodwill
Original cost	121		121		148
Accumulated amortization	(92)		(92)		(101)
Carrying value	29		29		47
Cardiac and Vascular Group
The changes in the carrying amount of goodwill
Beginning balance			2,636
Goodwill as a result of acquisitions			0
Purchase accounting adjustments, net			0
Currency adjustments, net			(2)
Ending balance	2,634		2,634
Restorative Therapies Group
The changes in the carrying amount of goodwill
Beginning balance			7,298
Goodwill as a result of acquisitions			413
Purchase accounting adjustments, net			1
Currency adjustments, net			(5)
Ending balance	$ 7,707		$ 7,707