Shareholders' Equity - Components of Accumulated Other Comprehensive Loss, Net of Tax (Parenthetical) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Gain on interest rate swap, net of income taxes of $0.4 on both dates
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	$ 0.4	$ 0.4
Defined benefit pension plans, net of income tax benefit of $(20.1) and $(20.4), respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	(20.1)	(20.4)
Gain (loss) on derivative instruments, net of income taxes (benefit) of $(8.1) and $(5.3), respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	(4.8)	(5.3)
Translation loss on long-term intercompany loans, net of income taxes of $19.1 on both dates
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	19.1	19.1
Retiree health care plan, net of income taxes of $1.8 and $1.9, respectively
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, income taxes	$ 1.8	$ 1.9