Goodwill and Other Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) $ in Millions	9 Months Ended
Jan. 25, 2019 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 39,543
Goodwill as a result of acquisitions	1,360
Currency translation and other	(900)
Ending balance	40,003
Cardiac and Vascular Group
Goodwill [Roll Forward]
Beginning balance	6,791
Goodwill as a result of acquisitions	0
Currency translation and other	(82)
Ending balance	6,709
Minimally Invasive Therapies Group
Goodwill [Roll Forward]
Beginning balance	21,155
Goodwill as a result of acquisitions	82
Currency translation and other	(691)
Ending balance	20,546
Restorative Therapies Group
Goodwill [Roll Forward]
Beginning balance	9,717
Goodwill as a result of acquisitions	1,254
Currency translation and other	(126)
Ending balance	10,845
Diabetes Group
Goodwill [Roll Forward]
Beginning balance	1,880
Goodwill as a result of acquisitions	24
Currency translation and other	(1)
Ending balance	$ 1,903

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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