Post Employment Plans - Projected Benefit Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Settlements	$ 0.0
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning	165.4
Settlements	0.0
Fair value of plan assets at end of period	189.1	$ 165.4
Pension plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, beginning	186.9	168.6
Curtailment	0.0	(2.5)
Service costs	2.7	2.5	$ 3.0
Interest cost	2.8	3.8	3.8
Actuarial loss (gain)	7.0	22.7
Amendments	0.0	0.0
Contributions paid	0.2	0.3
Benefits paid	(2.3)	(1.6)
Settlements	0.0	(3.8)
Foreign currency translation	17.0	(3.1)
Projected benefit obligation, ending	214.3	186.9	168.6
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning	165.4	151.9
Actual return on plan assets	8.3	19.8
Benefits paid	(2.3)	(1.6)
Settlements	0.0	(3.8)
Employer contributions	2.3	2.0
Contributions paid	0.2	0.3
Foreign currency translation	15.2	(3.2)
Fair value of plan assets at end of period	189.1	165.4	151.9
Unfunded status	(25.2)	(21.5)
Presented as:
Other non-current assets	17.9	15.8
Other non-current liabilities	(43.1)	(37.3)
Other Postretirement Benefits Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, beginning	3.7	5.6
Curtailment	0.0	0.0
Service costs	0.0	0.6	0.6
Interest cost	0.1	0.2	0.2
Actuarial loss (gain)	(0.2)	0.3
Amendments	0.0	(2.9)
Contributions paid	0.0	0.0
Benefits paid	(0.1)	(0.1)
Settlements		0.0
Foreign currency translation	0.0	0.0
Projected benefit obligation, ending	3.5	3.7	5.6
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning	0.0	0.0
Actual return on plan assets	0.0	0.0
Benefits paid	(0.1)	(0.1)
Settlements		0.0
Employer contributions	0.1	0.1
Contributions paid	0.0	0.0
Foreign currency translation	0.0	0.0
Fair value of plan assets at end of period	0.0	0.0	$ 0.0
Unfunded status	(3.5)	(3.7)
Presented as:
Other non-current assets	0.0	0.0
Other non-current liabilities	$ 0.0	$ 0.0