Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income [Roll Forward]
Balance		$ 5,803.8	$ 5,668.0	$ 6,170.5
OCI before reclassifications		217.6	60.1
Amounts reclassified from AOCI		38.0	(5.3)
Other comprehensive income (loss), net of tax		255.6	54.8	(167.5)
Balance		5,655.1	5,803.8	5,668.0
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income [Roll Forward]
Balance		139.4	84.6	253.1
Other comprehensive income (loss), net of tax		255.6	54.8	(167.5)
Balance		395.0	139.4	84.6
Fair Value of Derivative Financial Instruments, net of tax
Accumulated Other Comprehensive Income [Roll Forward]
Balance		12.7	(15.5)
OCI before reclassifications		(12.2)	26.8
Amounts reclassified from AOCI		(1.2)	1.4
Other comprehensive income (loss), net of tax		(13.4)	28.2
Balance		(0.7)	12.7	(15.5)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income [Roll Forward]
Balance	[1]	132.9	104.5
OCI before reclassifications	[1]	228.0	28.4
Amounts reclassified from AOCI	[1]	46.4	0.0
Other comprehensive income (loss), net of tax	[1]	274.4	28.4
Balance	[1]	407.3	132.9	104.5
Post-Retirement and Pension Liability Adjustments, net of tax
Accumulated Other Comprehensive Income [Roll Forward]
Balance		(6.2)	(4.4)
OCI before reclassifications		1.8	4.9
Amounts reclassified from AOCI		(7.2)	(6.7)
Other comprehensive income (loss), net of tax		(5.4)	(1.8)
Balance		$ (11.6)	$ (6.2)	$ (4.4)

[1] Refer to the description in Note 3 of the Rosemont Pharmaceuticals business divestiture for information regarding amounts reclassified from AOCI