Post Retirement Benefit Plans - Changes in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in benefit obligation:
Benefit obligation at beginning of year	$ 275.2	$ 255.0
Service cost	8.1	8.2	$ 6.4
Interest cost	0.5	1.1	2.6
Plan participant contributions	5.2	4.4
Plan amendments	(10.9)	(2.8)
Plan settlements	(0.5)
Benefits paid	(6.4)	(5.7)
Actuarial loss (gain)	(5.4)	(6.7)
Premiums paid	(1.8)	(1.4)
Impact of foreign currency exchange rates	(10.1)	23.1
Benefit obligation at end of year	253.9	275.2	255.0
Change in plan assets:
Fair value of plan assets at beginning of year	150.5	131.4
Return on plan assets	(2.1)	3.1
Plan participant and employer contributions	12.4	10.7
Benefits paid	(6.4)	(5.7)
Plan settlements	(0.5)
Premiums paid	(1.8)	(1.5)
Impact of foreign currency exchange rates	(4.3)	12.5
Fair value of plan assets at end of year	147.8	150.5	$ 131.4
Net under funded status	(106.1)	(124.7)
Accumulated benefit obligation	$ 225.8	$ 260.4