Goodwill and Other Intangibles (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-lived intangible assets:
Total goodwill	$ 4,370.1	$ 3,972.7
Weighted-average useful life (in years)	12 years
Amortization of intangible assets	$ 683.4	687.9	$ 631.8
Maximum
Finite-lived intangible assets:
Useful life (in years)	20 years
Minimum
Finite-lived intangible assets:
Useful life (in years)	3 years
Human pharmaceutical products
Finite-lived intangible assets:
Total goodwill	$ 1,366.8	1,366.4
Animal health products
Finite-lived intangible assets:
Total goodwill	$ 3,003.3	$ 2,606.3