Financial Instruments and Fair Value Measurement - Fair Value Hierarchy (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	$ 50.7	$ 51.2
Trading securities	19.2	14.3
Deferred compensation plan liabilities	(19.2)	(14.3)
Derivatives:
Forward exchange contracts-Assets	0.0	1.6
Forward exchange contracts-(Liabilities)	(0.3)	0.0
Fair value, net asset (liability)	77.9	88.8
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	0.0	0.0
Trading securities	19.2	14.3
Deferred compensation plan liabilities	(19.2)	(14.3)
Derivatives:
Forward exchange contracts-Assets	0.0	0.0
Forward exchange contracts-(Liabilities)	0.0	0.0
Fair value, net asset (liability)	27.5	15.1
Quoted Prices in Active Markets for Similar Assets (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	50.7	48.9
Trading securities	0.0	0.0
Deferred compensation plan liabilities	0.0	0.0
Derivatives:
Forward exchange contracts-Assets	0.0	1.6
Forward exchange contracts-(Liabilities)	(0.3)	0.0
Fair value, net asset (liability)	50.4	71.4
Unobservable inputs for which little or no market data exists (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investments	0.0	2.3
Trading securities	0.0	0.0
Deferred compensation plan liabilities	0.0	0.0
Derivatives:
Forward exchange contracts-Assets	0.0	0.0
Forward exchange contracts-(Liabilities)	0.0	0.0
Fair value, net asset (liability)	0.0	2.3
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	27.5	15.1
Money Market Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	27.5	15.1
Money Market Funds | Quoted Prices in Active Markets for Similar Assets (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	0.0	0.0
Money Market Funds | Unobservable inputs for which little or no market data exists (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents	$ 0.0	0.0
Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents		20.9
Time Deposits | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents		0.0
Time Deposits | Quoted Prices in Active Markets for Similar Assets (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents		20.9
Time Deposits | Unobservable inputs for which little or no market data exists (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents		$ 0.0