Acquisitions , Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Apr. 26, 2019	Mar. 08, 2019	Dec. 18, 2018	Apr. 27, 2018	Apr. 28, 2017
Business Acquisition [Line Items]
Goodwill	$ 39,959			$ 39,543	$ 38,515
Total
Business Acquisition [Line Items]
Cash and cash equivalents	115
Investments	52
Accounts receivable	12
Inventory	34
Other current assets	6
Property, plant, and equipment	33
Goodwill	1,510			52
Other intangible assets	771
Tax assets	13
Other assets	3
Total assets acquired	2,549			156
Current liabilities	103
Accrued income taxes	5
Deferred tax liabilities	69
Total liabilities assumed	177			4
Net assets acquired	2,372			$ 152
Mazor Robotics
Business Acquisition [Line Items]
Cash and cash equivalents			$ 109
Investments			52
Accounts receivable			10
Inventory			7
Other current assets			2
Property, plant, and equipment			3
Goodwill			1,197
Other intangible assets			399
Tax assets			6
Other assets			1
Total assets acquired			1,786
Current liabilities			54
Accrued income taxes			0
Deferred tax liabilities			58
Total liabilities assumed			112
Net assets acquired			$ 1,674
EPiX Therapeutics, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents		$ 3
Investments		0
Accounts receivable		0
Inventory		0
Other current assets		1
Property, plant, and equipment		1
Goodwill		165
Other intangible assets		162
Tax assets		0
Other assets		2
Total assets acquired		334
Current liabilities		4
Accrued income taxes		0
Deferred tax liabilities		11
Total liabilities assumed		15
Net assets acquired		$ 319
All Other
Business Acquisition [Line Items]
Cash and cash equivalents	3
Investments	0
Accounts receivable	2
Inventory	27
Other current assets	3
Property, plant, and equipment	29
Goodwill	148
Other intangible assets	210
Tax assets	7
Other assets	0
Total assets acquired	429
Current liabilities	45
Accrued income taxes	5
Deferred tax liabilities	0
Total liabilities assumed	50
Net assets acquired	$ 379