Acquisitions (Narrative) (Details) $ / shares in Units, $ in Millions				3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 17, 2021 USD ($)	Apr. 30, 2020 USD ($) $ / shares	Mar. 31, 2020 USD ($)	Jul. 02, 2021 USD ($)	Apr. 02, 2021 USD ($)	Oct. 02, 2020 USD ($)	Jul. 03, 2020 USD ($)	Jul. 02, 2021 USD ($) Business	Jul. 03, 2020 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Number of businesses acquired | Business								9
Net cash consideration								$ 1,065	$ 20,736
Number of segments reported | Business								3
Proceeds from sale of product lines		$ 826			$ 26	$ 16	$ 810	$ 26	810
Pretax gain on sale of product lines		455		$ 0	13		455	13	455
Gain on sale of product lines, net of tax		$ 305			$ 10		$ 305		305
Gain on sale of product lines, net of tax, per diluted common share | $ / shares		$ 0.42
Disposal group, product lines, revenues										$ 88	$ 170
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
Aldevron, pending acquisition
Business Acquisition [Line Items]
Net cash consideration	$ 9,600
Revenue reported by acquired entity for last annual period	$ 300
Series of individually immaterial business acquisitions
Business Acquisition [Line Items]
Revenue reported by acquired entity for last annual period								$ 93