Shareholders' Equity - Components of Accumulated Other Comprehensive Loss, Net of Tax (Parenthetical) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Translation gain (loss) on derivative instruments, net of income taxes of $(10.9) and $(12.9), respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	$ (1.3)	$ (12.9)
Defined benefit pension plans and Retiree health care plan | Defined benefit pension plans, net of income taxes of $(23.0) and $(23.2), respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	(22.9)	(23.2)
Defined benefit pension plans and Retiree health care plan | Retiree health care plan, net of income taxes of $1.9 and $2.0 for 2019 and 2018, respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	$ 1.9	$ 2.0