Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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Fair value portion of notes payable.

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Derivative Financial Instruments and Fair Value Measurements - Additional Information (Details) $ in Millions	Sep. 30, 2019 USD ($)	Sep. 30, 2019 EUR (€)	Apr. 30, 2019 EUR (€)	Dec. 31, 2018 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of long-term debt	$ 1,045.7			$ 1,053.0
Level 1 Inputs \| Fair value measured on a recurring basis
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred compensation plan assets	101.4			89.5
Euro-denominated notes \| Fair value \| Level 2 Inputs
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of long-term debt	1,045.7			1,052.9
Euro-denominated notes \| Carrying value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of long-term debt	$ 974.3			$ 1,024.6
Cross-currency swap \| Cash flow hedge
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt \| €		€ 55,400,000	€ 202,300,000
Fixed annual interest rate	1.143%	1.143%	1.256%
Designated as hedging instrument \| Notes due September 2022 \| Euro-denominated notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 434.4	€ 400,000,000.0
Designated as hedging instrument \| Notes Due June 2026 \| Euro-denominated notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 539.9	€ 500,000,000.0