Pension Plans - Changes in Value for Level 3 Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Gains (losses) on assets held	$ 1.7	$ 0.7
Purchases, sales and settlements, net	0.2	0.5
Foreign Plan
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value of plan assets, beginning	14.9	13.7
Fair value of plan assets, ending	15.5	14.9
Foreign Plan | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value of plan assets, beginning	10.2	9.0
Fair value of plan assets, ending	$ 12.1	$ 10.2