Acquisitions (Narrative) (Details) $ / shares in Units, $ in Millions				3 Months Ended			9 Months Ended		12 Months Ended
	Aug. 30, 2021 USD ($)	Apr. 30, 2020 USD ($) $ / shares	Mar. 31, 2020 USD ($)	Oct. 01, 2021 USD ($)	Apr. 02, 2021 USD ($)	Oct. 02, 2020 USD ($)	Oct. 01, 2021 USD ($) Business_Segments Business	Oct. 02, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Net cash consideration							$ 10,628	$ 20,819
Number of segments reported | Business_Segments							3
Proceeds from sale of product lines		$ 826			$ 26		$ 26	826
Pretax gain on sale of product lines		455		$ 0	13	$ 0	13	455
Gain on sale of product lines, net of tax		$ 305			$ 10			305
Gain on sale of product lines, net of tax, per diluted common share | $ / shares		$ 0.42
Disposal group, product lines, revenues									$ 88	$ 170
Aldevron
Business Acquisition [Line Items]
Net cash consideration	$ 9,600						9,563
Revenue reported by acquired entity for last annual period	$ 300
Aldevron | Fair value adjustment to inventory
Business Acquisition [Line Items]
Pro forma earnings, adjustments				17			17
Aldevron | Acquisition-related transaction costs
Business Acquisition [Line Items]
Pro forma earnings, adjustments				$ 28			28
Series of individually immaterial business acquisitions
Business Acquisition [Line Items]
Net cash consideration							1,065
Revenue reported by acquired entity for last annual period							$ 93
Number of businesses acquired | Business							9
Cytiva
Business Acquisition [Line Items]
Consideration transferred			$ 20,700
Cash acquired			100
Pension liabilities			$ 400
Cytiva | Fair value adjustment to inventory
Business Acquisition [Line Items]
Pro forma earnings, adjustments							$ 46
Cytiva | Acquisition-related transaction costs
Business Acquisition [Line Items]
Pro forma earnings, adjustments								$ 59