Benefit Plans - Changes in Projected Benefit Obligation, Fair Value of Plan Assets and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in plan assets:
Balance	$ 249.2
Balance	29.4	$ 249.2
Pension benefits
Change in benefit obligation:
Balance	(269.8)	(298.9)
Service cost	(1.5)	(1.6)	$ (1.5)
Interest cost	(4.2)	(6.2)	(7.1)
Participants’ contributions	(0.4)	(0.6)
Actuarial gain (loss)	33.0	12.1
Amendments/transfers in	0.0	2.0
Benefits paid	6.9	7.1
Settlement loss	174.4	13.1
Foreign currency translation	6.1	3.2
Balance	(55.5)	(269.8)	(298.9)
Change in plan assets:
Balance	249.2	258.1
Actual return on plan assets	(42.4)	6.1
Employer contribution	8.4	3.6
Participants’ contributions	0.4	0.6
Benefits paid	(7.2)	(5.2)
Settlement loss	(174.4)	(13.1)
Foreign currency translation	(4.6)	(0.9)
Balance	29.4	249.2	258.1
Funded status at end of year	(26.1)	(20.6)
Other retirement benefits
Change in benefit obligation:
Balance	(5.6)	(6.1)
Service cost	0.0	0.0	0.0
Interest cost	(0.2)	(0.2)	(0.2)
Participants’ contributions	(0.4)	(0.5)
Actuarial gain (loss)	2.0	0.9
Amendments/transfers in	0.0	0.0
Benefits paid	0.3	0.3
Settlement loss	0.0	0.0
Foreign currency translation	0.0	0.0
Balance	(3.9)	(5.6)	(6.1)
Change in plan assets:
Balance	0.0	0.0
Actual return on plan assets	0.0	0.0
Employer contribution	(0.1)	(0.2)
Participants’ contributions	0.4	0.5
Benefits paid	(0.3)	(0.3)
Settlement loss	0.0	0.0
Foreign currency translation	0.0	0.0
Balance	0.0	0.0	$ 0.0
Funded status at end of year	$ (3.9)	$ (5.6)