Acquisitions - Narrative (Details) - USD ($)		3 Months Ended		9 Months Ended		13 Months Ended
	Dec. 18, 2018	Jan. 24, 2020	Jan. 25, 2019	Jan. 24, 2020	Jan. 25, 2019	Jan. 24, 2020	Oct. 25, 2019	Apr. 26, 2019	Oct. 26, 2018	Apr. 27, 2018
Business Acquisition [Line Items]
Goodwill		$ 40,091,000,000		$ 40,091,000,000		$ 40,091,000,000		$ 39,959,000,000
Purchase price contingent consideration		45,000,000	$ 5,000,000	110,000,000	$ 51,000,000
Purchase accounting adjustments. net increase to goodwill				123,000,000
Contingent consideration liabilities		304,000,000	148,000,000	304,000,000	148,000,000	304,000,000	$ 260,000,000	222,000,000	$ 203,000,000	$ 173,000,000
Other accrued expenses
Business Acquisition [Line Items]
Contingent consideration liabilities		147,000,000		147,000,000		147,000,000		73,000,000
Other liabilities
Business Acquisition [Line Items]
Contingent consideration liabilities		157,000,000		157,000,000		157,000,000		$ 149,000,000
IPR&D
Business Acquisition [Line Items]
In-process research and development acquired in connection with asset acquisition		0	15,000,000	0	15,000,000
All Business Acquisitions
Business Acquisition [Line Items]
Net assets acquired		272,000,000		272,000,000		272,000,000
Total assets acquired		324,000,000		324,000,000		324,000,000
Total liabilities assumed		52,000,000		52,000,000		52,000,000
Goodwill		92,000,000		92,000,000		92,000,000
Inventory		40,000,000		40,000,000		40,000,000
Purchase price contingent consideration				65,000,000
All Business Acquisitions | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired		139,000,000		$ 139,000,000		139,000,000
All Business Acquisitions | Technology-Based Intangible Assets | Minimum
Business Acquisition [Line Items]
Estimated useful life				8 years
All Business Acquisitions | Technology-Based Intangible Assets | Maximum
Business Acquisition [Line Items]
Estimated useful life				16 years
All Business Acquisitions | Customer-Related Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired		$ 26,000,000		$ 26,000,000		26,000,000
All Business Acquisitions | Customer-Related Intangible Assets | Minimum
Business Acquisition [Line Items]
Estimated useful life				8 years
All Business Acquisitions | Customer-Related Intangible Assets | Maximum
Business Acquisition [Line Items]
Estimated useful life				16 years
Mazor Robotics
Business Acquisition [Line Items]
Net assets acquired	$ 1,674,000,000
Total assets acquired	1,905,000,000
Total liabilities assumed	231,000,000
Intangible assets acquired	399,000,000
Goodwill	1,318,000,000
Inventory	5,000,000
Cash consideration	1,300,000,000
Total consideration for the transaction, net of cash acquired, including previously-held equity investment	1,600,000,000
Previously-held equity investment	246,000,000
Costs incurred in connection with acquisition			51,000,000		51,000,000
Purchase accounting adjustments. net increase to goodwill						$ 105,000,000
Mazor Robotics | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired	$ 383,000,000
Estimated useful life	10 years
Mazor Robotics | Tradenames
Business Acquisition [Line Items]
Intangible assets acquired	$ 16,000,000
Estimated useful life	10 years
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Net assets acquired			377,000,000		377,000,000
Total assets acquired			427,000,000		427,000,000
Total liabilities assumed			50,000,000		50,000,000
Goodwill			146,000,000		146,000,000
Purchase price contingent consideration					51,000,000
Series of Individually Immaterial Business Acquisitions | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired			161,000,000		$ 161,000,000
Series of Individually Immaterial Business Acquisitions | Technology-Based Intangible Assets | Minimum
Business Acquisition [Line Items]
Estimated useful life					4 years
Series of Individually Immaterial Business Acquisitions | Technology-Based Intangible Assets | Maximum
Business Acquisition [Line Items]
Estimated useful life					15 years
Series of Individually Immaterial Business Acquisitions | Customer-Related Intangible Assets
Business Acquisition [Line Items]
Intangible assets acquired			$ 40,000,000		$ 40,000,000
Series of Individually Immaterial Business Acquisitions | Customer-Related Intangible Assets | Minimum
Business Acquisition [Line Items]
Estimated useful life					10 years
Series of Individually Immaterial Business Acquisitions | Customer-Related Intangible Assets | Maximum
Business Acquisition [Line Items]
Estimated useful life					13 years