Goodwill and Other Intangible Assets, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Jul. 25, 2014	Jul. 26, 2013	Apr. 25, 2014
The changes in the carrying amount of goodwill
Beginning balance	$ 10,593
Goodwill as a result of acquisitions	99
Goodwill, Purchase Accounting Adjustments	(2)
Currency adjustments, net	6
Ending balance	10,696
Balance of intangible assets, excluding goodwill
Intangible Assets, Gross (Excluding Goodwill)	4,706		4,584
Accumulated amortization	(2,365)		(2,298)
Carrying value	2,225
Intangible Assets, Net (Excluding Goodwill)	2,341		2,286
Amortization expense	87	86
Estimated aggregate amortization expense
Remaining 2015	275
2016	331
2017	309
2018	293
2019	249
2020	204
Thereafter	564
Purchased Technology and Patents
Balance of intangible assets, excluding goodwill
Original cost	3,992		3,857
Accumulated amortization	(1,946)		(1,878)
Carrying value	2,046		1,979
Trademarks and Tradenames
Balance of intangible assets, excluding goodwill
Original cost	408		408
Accumulated amortization	(337)		(332)
Carrying value	71		76
Other
Balance of intangible assets, excluding goodwill
Original cost	190		200
Accumulated amortization	(82)		(88)
Carrying value	108		112
Cardiac and Vascular Group
The changes in the carrying amount of goodwill
Beginning balance	2,881
Goodwill as a result of acquisitions	50
Goodwill, Purchase Accounting Adjustments	(2)
Currency adjustments, net	5
Ending balance	2,934
Restorative Therapies Group
The changes in the carrying amount of goodwill
Beginning balance	6,368
Goodwill as a result of acquisitions	49
Goodwill, Purchase Accounting Adjustments	0
Currency adjustments, net	1
Ending balance	6,418
Diabetes Group [Member]
The changes in the carrying amount of goodwill
Beginning balance	1,344
Goodwill as a result of acquisitions	0
Goodwill, Purchase Accounting Adjustments	0
Currency adjustments, net	0
Ending balance	1,344
In Process Research and Development [Member]
Balance of intangible assets, excluding goodwill
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 116		$ 119