Shareholders' Equity - Components of Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ 2,605.4	$ 2,542.8	$ 2,639.0	$ 2,761.5	$ 2,716.1	$ 2,694.5	$ 2,649.9	$ 2,698.5
Foreign currency translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(231.4)			(260.5)
Translation (loss) gain on derivative instruments, net of income taxes of $(21.6) and $(9.1), respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(10.7)			13.1
Translation loss on long-term intercompany loans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(127.7)			(121.5)
Defined benefit pension plans and Retiree health care plan | Defined benefit pension plans, net of income taxes of $(35.2) and $(30.9), respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(64.6)			(74.1)
Defined benefit pension plans and Retiree health care plan | Retiree health care plan, net of income taxes of $2.2 and $1.6, respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	1.6			2.0
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (432.8)	$ (479.1)	$ (505.8)	$ (441.0)	$ (452.5)	$ (416.5)	$ (401.8)	$ (399.8)