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Goodwill and Other Intangibles - Goodwill Activity by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	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

X

- 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

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-Publisher FASB
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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

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Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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