Retirement and Other Postretirement Benefit Plans - Schedule of Benefit Obligation, Fair Value of Plan Assets, Funded Status and Amounts Recognized in the Consolidated Financial Statements (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets:
Fair value of plan assets – beginning of year		$ 184.3
Fair value of plan assets – end of year		214.3	$ 184.3
Amounts recognized in Consolidated Balance Sheets:
Non-current liabilities		53.3	42.0
Postretirement Plans
Change in benefit obligation:
Benefit obligation – beginning of year		3.3	4.1
Interest cost		0.1	0.1	$ 0.1
Plan participants’ contributions		0.3
Actuarial loss (gain)		0.2	(0.7)
Benefits and expenses paid		(0.8)	(0.2)
Benefit obligation – end of year		3.1	3.3	4.1
Change in plan assets:
Employer contributions		0.5	0.2
Plan participants’ contributions		0.3
Benefits and expenses paid		(0.8)	(0.2)
Amounts recognized in Consolidated Balance Sheets:
Current liabilities		0.5	0.5
Non-current liabilities		2.6	2.8
Total liabilities	[1]	3.1	3.3
Amounts recognized in Accumulated Other Comprehensive Loss:
Actuarial net (loss) gain		1.8	3.0
Total amounts recognized in accumulated other comprehensive (loss) income		1.8	3.0
U.S. Plans | Defined Benefit Retirement Plans
Change in benefit obligation:
Benefit obligation – beginning of year		18.2	21.4
Service cost		1.2	1.2	1.3
Interest cost		0.6	0.6	0.6
Actuarial loss (gain)		0.9	(0.7)
Benefits and expenses paid		(0.6)	(4.3)
Benefit obligation – end of year		20.3	18.2	21.4
Change in plan assets:
Employer contributions		0.6	4.3
Benefits and expenses paid		(0.6)	(4.3)
Amounts recognized in Consolidated Balance Sheets:
Current liabilities		1.4	0.9
Non-current liabilities		18.9	17.3
Total liabilities	[1]	20.3	18.2
Amounts recognized in Accumulated Other Comprehensive Loss:
Actuarial net (loss) gain		(3.0)	(3.1)
Prior service cost			1.0
Total amounts recognized in accumulated other comprehensive (loss) income		(3.0)	(2.1)
European Plans | Defined Benefit Retirement Plans
Change in benefit obligation:
Benefit obligation – beginning of year		160.9	189.5
Service cost		1.0	1.1	1.0
Interest cost		4.5	4.4	4.6
Plan participants’ contributions			1.3
Actuarial loss (gain)		22.0	(20.4)
Curtailments and settlements		(0.4)	(0.4)
Benefits and expenses paid		(5.2)	(5.2)
Currency translation adjustments		5.8	(9.4)
Benefit obligation – end of year		188.6	160.9	189.5
Change in plan assets:
Fair value of plan assets – beginning of year		184.3	201.8
Actual return on plan assets		22.2	(6.0)
Employer contributions		5.2	5.0
Benefits and expenses paid		(5.2)	(5.2)
Curtailments and settlements		(0.2)	(0.4)
Currency translation adjustments		8.0	(10.9)
Fair value of plan assets – end of year		214.3	184.3	$ 201.8
Amounts recognized in Consolidated Balance Sheets:
Non-current assets		45.2	42.6
Current liabilities		0.6	0.4
Non-current liabilities		18.9	18.8
Total liabilities	[1]	19.5	19.2
Amounts recognized in Accumulated Other Comprehensive Loss:
Actuarial net (loss) gain		(28.8)	(20.0)
Prior service cost		(1.3)	(1.4)
Total amounts recognized in accumulated other comprehensive (loss) income		$ (30.1)	$ (21.4)

[1] The current and non-current portions of the accrued benefit costs for the defined benefit retirement plans and postretirement benefit plans are included within “accrued compensation and benefits” and “retirement obligations”, respectively, in the accompanying consolidated balance sheets.