Fair Value Measurements (Details 1) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Notes payable, carrying value	$ 6,494.7	$ 6,499.3
Debt instruments, fair value	7,048.3	6,808.4
Notes Payable to Fumedica
Debt Instrument [Line Items]
Notes payable, fair value	3.2	6.1
Notes payable, carrying value	3.3	6.0
6.875% Senior Notes due 2018
Debt Instrument [Line Items]
Notes payable, fair value	561.7	583.7
Notes payable, carrying value	553.1	558.5
2.900% Senior Notes due 2020
Debt Instrument [Line Items]
Notes payable, fair value	1,536.2	1,521.5
Notes payable, carrying value	1,486.5	1,485.3
3.625% Senior Notes due 2022
Debt Instrument [Line Items]
Notes payable, fair value	1,049.4	1,026.6
Notes payable, carrying value	994.0	993.2
4.050% Senior Notes due 2025
Debt Instrument [Line Items]
Notes payable, fair value	1,867.0	1,796.0
Notes payable, carrying value	1,735.9	1,734.8
5.200% Senior Notes due 2045
Debt Instrument [Line Items]
Notes payable, fair value	2,030.8	1,874.5
Notes payable, carrying value	$ 1,721.9	$ 1,721.5