Acquisitions and divestitures (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	12 Months Ended
	Dec. 22, 2022	Dec. 31, 2023	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022	Jun. 30, 2024
Business Acquisition [Line Items]
Acquisitions, net of cash acquired (Note 18)			$ 0	$ 17,652	$ 60
Payments to acquire businesses, gross				17,700
Liabilities				1,100
Tangible assets				17,300
Goodwill, related to acquisitions			0	11,056
Research and development in process			313	783	900
Contingent Consideration		$ 1,092	1,092	1,120
Intangible assets useful life	14 years
Acquisition related costs				300
Proceeds from divestiture of brands			200
Asset Acquisition, Consideration Transferred			500
Asset, held-for-sale, not part of disposal group		300	300
Goodwill, Purchase Accounting Adjustments			200
Laminar
Business Acquisition [Line Items]
Asset Acquisition, Consideration Transferred			400
MedTech
Business Acquisition [Line Items]
Goodwill, related to acquisitions			0	11,056
Research and development in process					900
Acquisition costs, period cost			200	$ 300
Evra and Doxil
Business Acquisition [Line Items]
Proceeds from divestiture of brands					$ 600
Non-Tradeable Contingent Value Right
Business Acquisition [Line Items]
Dividends payable, amount per share (in dollars per share)	$ 8.75
Non-Tradeable Contingent Value Right | Class I Recommendation For Impella
Business Acquisition [Line Items]
Dividends payable, amount per share (in dollars per share)	$ 10.00
Ambrx
Business Acquisition [Line Items]
Equity interests issued and issuable		2,000
Acquisitions, net of cash acquired (Note 18)		1,900
Ambrx | Forecast
Business Acquisition [Line Items]
Acquisition price (in dollars per share)						$ 28.00
Abiomed
Business Acquisition [Line Items]
Equity interests issued and issuable	$ 17,100
Acquisition price (in dollars per share)	$ 380.00
Liabilities		3,000	3,000
Cash and equivalents	$ 16,500
Other assets assumed		20,100	20,100
Cash acquired from acquisition			300
Goodwill, related to acquisitions			11,100
Finite-lived intangible assets acquired			6,600
Research and development in process			1,100
Marketable securities assumed		600	600
Contingent Consideration		704	704
Deferred tax liability, acquisition		$ 2,000	$ 2,000
Discount rate	9.50%
Abiomed | Minimum
Business Acquisition [Line Items]
Probability of success factor	52.00%
Abiomed | Maximum
Business Acquisition [Line Items]
Probability of success factor	70.00%
Abiomed | Non-Tradeable Contingent Value Right
Business Acquisition [Line Items]
Non-tradeable contingent value right (in dollars per share)	$ 35.00
Non-tradeable contingent value right	$ 1,600
Dividends payable, amount per share (in dollars per share)	$ 17.50
Contingent consideration	$ 3,700
Abiomed | Non-Tradeable Contingent Value Right | Impella
Business Acquisition [Line Items]
Dividends payable, amount per share (in dollars per share)	$ 7.50