Pension Plans - Actuarial Present Value of Projected Benefit Obligation and Plan Assets (Details) - Foreign Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, beginning	$ 90.6	$ 75.5
Service cost	3.1	2.4	$ 2.6
Interest cost	2.1	2.4	2.3
Actuarial loss	3.5	13.4
Benefits paid	(2.8)	(2.4)
Participant contributions	0.3	0.3
Settlements	(0.5)	0.0
Curtailments	0.0	0.0
Foreign currency translation and other	7.2	(1.0)
Projected benefit obligation, ending	103.5	90.6	75.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning	14.9	13.7
Actual return on plan assets	1.2	1.0
Employer contributions	2.6	2.4
Participants' contributions	0.3	0.3
Benefits paid	(2.7)	(2.4)
Settlements	(0.5)	0.0
Foreign currency translation and other	(0.3)	(0.1)
Fair value of plan assets, ending	15.5	14.9	$ 13.7
Amounts recognized in the balance sheet:
Noncurrent asset	0.4	0.5
Current liability	(2.3)	(2.2)
Noncurrent liability	(86.1)	(74.0)
Net amount recognized in the balance sheet	(88.0)	(75.7)
Pretax accumulated other comprehensive (income) loss	$ 19.1	$ 15.0