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Fair Value Measurements (Details Textual) SFr in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2006 CHF (SFr)
Business Acquisition, Contingent Consideration [Line Items]
Asset impairment charges	$ 0.0
Fair value measurements, changes in valuation inputs	0
Notes payable	$ 5,928.4	$ 5,938.2
Contingent consideration obligations	270.5	279.0
Notes Payable To Fumedica
Business Acquisition, Contingent Consideration [Line Items]
Notes payable	$ 0.0	3.2	SFr 61.4
2.900% Senior Notes due 2020
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	2.90%
Notes payable	$ 1,474.3	1,482.4
3.625% Senior Notes due 2022
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	3.625%
Notes payable	$ 994.9	994.3
4.050% Senior Notes due 2025
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	4.05%
Notes payable	$ 1,737.0	1,736.3
5.200% Senior Notes due 2045
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	5.20%
Notes payable	$ 1,722.2	$ 1,722.0