Goodwill and Other Intangible Assets (Finite-lived and Indefinite-lived Intangible Assets) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jul. 31, 2018
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount		$ 2,869	$ 2,803
Finite-lived intangible assets, Accumulated Amortization		(1,358)	(1,129)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization		1,511	1,674
Indefinite-lived intangible assets:		199	216
Intangible Assets, Gross Carrying Amount		3,068	3,019
Identifiable Intangible Assets, Less Accumulated Amortization		$ 1,710	1,890
Weighted average life our finite lived intangible assets		10 years
Amortization expense of finite-lived intangible assets		$ 230	237	$ 157
2019		203
2020		191
2021		183
2022		164
2023		149
Brands and tradenames(a)
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:		104	104
In Process Research and Development
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:		88	105
Product rights
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:		7	7
Developed Technology Rights
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	[1]	1,968	1,938
Finite-lived intangible assets, Accumulated Amortization	[1]	(809)	(657)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization	[1]	1,159	1,281
Brands and tradenames(a)
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount		427	424
Finite-lived intangible assets, Accumulated Amortization		(243)	(223)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization		184	201
Other Intangible Assets
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount		474	441
Finite-lived intangible assets, Accumulated Amortization		(306)	(249)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization		$ 168	$ 192
Abaxis Inc
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Identifiable intangible assets					$ 894

[1] In 2020, additions included intangible assets associated with the acquisitions of Performance Livestock Analytics, Virtual Recall, Ethos Diagnostic Science and Fish Vet Group. See Note 5. Acquisitions and Divestitures.