Asset Impairment, Restructuring, and Other Special Charges (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Severance	$ 0.0	$ (24.6)	$ (3.6)	$ (17.3)
Asset impairment and other special charges	0.0	(0.9)	427.5	48.6
Total asset impairment, restructuring, and other special charges	$ 0.0	$ (25.5)	423.9	$ 31.3
Loxo Oncology, Inc.
Business Acquisition [Line Items]
Asset impairment and other special charges			$ 400.7

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of restructuring charges, remediation cost, and asset impairment loss.

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Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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