CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, tax	$ 1.0	$ 2.2	$ 2.4
Prior service credit arising during period, tax	0.0	0.0	0.5
Net actuarial gain (loss) arising during period, tax	0.4	(2.4)	2.1
Settlement effects arising during period, tax	0.0	20.3	0.4
Less: amortization of actuarial loss, tax	(0.4)	(0.1)	0.1
Less: amortization of prior service credit, tax	0.0	0.0	(0.1)
Less: amortization of other, net of tax	(0.1)	0.1	0.0
Net gain (loss) on investment securities, tax	0.0	0.0	0.0
Net gain (loss) on derivatives, tax	$ 0.0	$ 0.2	$ 0.5