Goodwill and Other Intangible Assets (Finite-lived and Indefinite-lived Intangible Assets) (Details) - USD ($) $ in Millions			12 Months Ended
		Jul. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount			$ 2,644	$ 1,694
Finite-lived intangible assets, Accumulated Amortization			(906)	(761)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization			1,738	933
Indefinite-lived intangible assets:			308	336
Intangible Assets, Gross Carrying Amount			2,952	2,030
Identifiable Intangible Assets, Less Accumulated Amortization			$ 2,046	1,269
Weighted average life our finite lived intangible assets			10 years
Amortization expense of finite-lived intangible assets			$ 157	100	$ 95
2019			231
2020			211
2021			182
2022			172
2023			162
Brands
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:			37	37
Trademarks and tradenames
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:			67	67
In Process Research and Development
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:	[1],[2]		197	224
Product rights
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets:			7	8
Developed Technology Rights
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	[1],[3],[4]		1,854	1,185
Finite-lived intangible assets, Accumulated Amortization	[1],[3],[4]		(523)	(428)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization	[1],[3],[4]		1,331	757
Identifiable intangible assets		$ 611
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		10 years
Brands
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount			212	213
Finite-lived intangible assets, Accumulated Amortization			(154)	(143)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization			58	70
Trademarks and tradenames
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	[3]		166	62
Finite-lived intangible assets, Accumulated Amortization	[3]		(51)	(47)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization	[3]		115	15
Identifiable intangible assets		$ 104
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		20 years
Other Intangible Assets
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, Gross Carrying Amount	[3],[5]		412	234
Finite-lived intangible assets, Accumulated Amortization	[3],[5]		(178)	(143)
Finite-lived intangible assets, Identifiable Intangible Assets, Less Accumulated Amortization	[3],[5]		$ 234	$ 91
Identifiable intangible assets		$ 180
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		4 years
Abaxis Inc
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Identifiable intangible assets		$ 895

[1] In the first quarter of 2017, certain intangible assets, acquired in 2015 as part of the Pharmaq acquisition, were placed into service.

[2] Includes the intangible assets related to the acquisition of an Irish biologic therapeutics company in the third quarter of 2017.

[3] In connection with the acquisition of Abaxis, the company recorded $895 million of intangible assets, as shown in the table below, representing the preliminary fair value at the acquisition date. See Note 5. Acquisitions and Divestitures for additional information. Gross Carrying Weighted-average(MILLIONS OF DOLLARS)Amount Life (years)Finite-lived intangible assets: Developed technology rights$611 10Trademarks and tradenames104 20Other180 4Total $895

[4] Includes intangible assets associated with the acquisitions of a European livestock monitoring company and a Norwegian fish vaccination company.

[5] Includes the acquisition of land use rights in China in the fourth quarter of 2017.