Debt (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (17.7)	$ (20.7)
Total debt	2,360.1	2,472.3
Less current portion of long-term debt	24.5	29.0
Total long-term debt	2,335.6	2,443.3
Credit facility \| Term credit facility
Debt Instrument [Line Items]
Long-term debt, gross	$ 377.5	492.5
Senior Notes \| 3.912% Senior Notes due 2021
Debt Instrument [Line Items]
Interest rate	3.912%
Long-term debt, gross	$ 500.0	500.0
Senior Notes \| 4.272% Senior Notes due 2023
Debt Instrument [Line Items]
Interest rate	4.272%
Long-term debt, gross	$ 750.0	750.0
Senior Notes \| 4.900% Senior Notes due 2028
Debt Instrument [Line Items]
Interest rate	4.90%
Long-term debt, gross	$ 750.0	750.0
Other obligations
Debt Instrument [Line Items]
Long-term debt, gross	$ 0.3	$ 0.5

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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