Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total Revenue	$ 3,071.0	$ 3,066.8	$ 2,889.0
Companion Animal Disease Prevention
Disaggregation of Revenue [Line Items]
Total Revenue	787.9	804.6	660.2
Companion Animal Therapeutics
Disaggregation of Revenue [Line Items]
Total Revenue	348.0	283.1	260.8
Food Animal Future Protein & Health
Disaggregation of Revenue [Line Items]
Total Revenue	745.1	711.2	649.2
Food Animal Ruminants Swine
Disaggregation of Revenue [Line Items]
Total Revenue	1,110.3	1,174.0	1,175.0
Strategic Exits
Disaggregation of Revenue [Line Items]
Total Revenue	$ 79.7	$ 93.9	$ 143.8