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Goodwill and Other Intangibles - Goodwill Activity by Segment (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Goodwill [Roll Forward] |  |
Goodwill, Beginning Balance | $ 18,162 | $ 17,723
Acquisitions | 177 | 482
Impairments | (38) | (47)
Other | (17) | 4
Goodwill, Ending Balance | 18,284 | 18,162
Accumulated goodwill impairment losses | 225 | 187
Pharmaceutical |  |
Goodwill [Roll Forward] |  |
Goodwill, Beginning Balance | 16,075 | 15,862
Acquisitions | 0 | 207
Impairments | 0 | 0
Other | (9) | 6
Goodwill, Ending Balance | 16,066 | 16,075
All Other |  |
Goodwill [Roll Forward] |  |
Goodwill, Beginning Balance | 2,087 | 1,861
Acquisitions | 177 | 275
Impairments | (38) | (47)
Other | (8) | (2)
Goodwill, Ending Balance | $ 2,218 | $ 2,087

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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- Definition Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a,h) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
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