Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
Jan. 25, 2019	Jan. 26, 2018	Jan. 25, 2019	Jan. 26, 2018
Goodwill [Line Items]
Goodwill impairment	$ 0	$ 0	$ 0	$ 0
Definite-lived intangible asset charges		0	87,000,000	0
Impairment of indefinite-lived intangible assets	21,000,000	63,000,000	21,000,000	68,000,000
Amortization expense	436,000,000	461,000,000	1,327,000,000	1,375,000,000
Restorative Therapies Group
Goodwill [Line Items]
Definite-lived intangible asset charges	26,000,000		26,000,000
Impairment of indefinite-lived intangible assets	$ 11,000,000	$ 63,000,000	11,000,000	$ 63,000,000
Cardiac and Vascular Group
Goodwill [Line Items]
Definite-lived intangible asset charges			$ 61,000,000

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

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Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

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