Revenues Other Revenues (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total Revenues	$ 3,526.3	$ 3,439.0	$ 3,356.5	$ 3,131.1	$ 3,307.0	$ 3,077.8	$ 3,078.4	$ 2,810.7	$ 13,452.9	$ 12,273.9	$ 11,448.8
Royalty
Disaggregation of Revenue [Line Items]
Total Revenues									38.7	69.8	46.5
Other corporate revenues
Disaggregation of Revenue [Line Items]
Total Revenues									459.4	253.7	230.6
Other revenue
Disaggregation of Revenue [Line Items]
Total Revenues	$ 165.7	$ 147.2	$ 108.6	$ 164.4	$ 179.6	$ 48.8	$ 41.6	$ 90.0	585.9	360.0	316.4
Collaborative Arrangement | AbbVie
Disaggregation of Revenue [Line Items]
Total Revenues									(8.6)	(16.9)	(21.9)
Collaborative Arrangement | Samsung Bioepis
Disaggregation of Revenue [Line Items]
Total Revenues									96.4	42.7	20.2
Collaborative Arrangement | Sobi
Disaggregation of Revenue [Line Items]
Total Revenues									$ 0.0	$ 10.7	$ 41.0