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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, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Segment Reporting Information [Line Items] |  |  |
Depreciation and amortization | $ 4,519 | $ 4,676 | $ 5,471
Operating Segments |  |  |
Segment Reporting Information [Line Items] |  |  |
Equity (income) loss from affiliates | 4 | 7 | (105)
Depreciation and amortization | 335 | 212 | 183
Operating Segments | Pharmaceutical |  |  |
Segment Reporting Information [Line Items] |  |  |
Equity (income) loss from affiliates | 4 | 7 | (105)
Depreciation and amortization | 243 | 125 | 160
Operating Segments | Animal Health |  |  |
Segment Reporting Information [Line Items] |  |  |
Equity (income) loss from affiliates | 0 | 0 | 0
Depreciation and amortization | 82 | 75 | 10
Operating Segments | All Other |  |  |
Segment Reporting Information [Line Items] |  |  |
Equity (income) loss from affiliates | 0 | 0 | 0
Depreciation and amortization | $ 10 | $ 12 | $ 13

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- 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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 + Details
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