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Segment Reporting - Schedule of Equity Income from Affiliates and Depreciation and Amortization Included in Segment Profits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 3,652	$ 4,519	$ 4,676
Operating Segments
Segment Reporting Information [Line Items]
Equity (income) loss from affiliates	0	4	7
Depreciation and amortization	256	335	212
Operating Segments | Pharmaceutical
Segment Reporting Information [Line Items]
Equity (income) loss from affiliates	0	4	7
Depreciation and amortization	137	243	125
Operating Segments | Animal Health
Segment Reporting Information [Line Items]
Equity (income) loss from affiliates	0	0	0
Depreciation and amortization	109	82	75
Operating Segments | All Other
Segment Reporting Information [Line Items]
Equity (income) loss from affiliates	0	0	0
Depreciation and amortization	$ 10	$ 10	$ 12

X

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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