Revenue (Summary of Revenue Recognized) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 5,499.4	$ 5,636.7	$ 11,359.2	$ 10,728.9
Net product revenue
Disaggregation of Revenue [Line Items]
Revenue	5,077.7	5,168.7	10,481.2	9,861.0
Collaboration and other revenue
Disaggregation of Revenue [Line Items]
Revenue	421.7	468.0	878.0	867.9
Collaboration and other revenue associated with prior period transfers of intellectual property
Disaggregation of Revenue [Line Items]
Revenue	$ 34.7	$ 59.6	$ 70.0	$ 95.1