Debt - Components of Debt (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt payable—unconsolidated affiliate	$ 47.7	$ 48.1
Total debt	1,984.1	1,983.3
Debt payable within one year	22.5	22.3
Debt payable after one year	$ 1,961.6	$ 1,961.0
Weighted average interest rates on total debt	3.90%	3.90%
2025 Term Loan
Debt Instrument [Line Items]
Total debt	$ 936.8	$ 938.9
Unamortized discount and debt issuance costs	8.4	8.7
5.125% Senior Notes, Due 2021
Debt Instrument [Line Items]
Total debt	$ 696.2	$ 695.8
Interest rate (percent)	5.125%	5.125%
Unamortized discount and debt issuance costs	$ 3.8	$ 4.2
5.625% Senior Notes, Due 2024
Debt Instrument [Line Items]
Total debt	$ 297.2	$ 297.0
Interest rate (percent)	5.625%	5.625%
Unamortized discount and debt issuance costs	$ 2.8	$ 3.0
Other borrowings
Debt Instrument [Line Items]
Total debt	$ 6.2	$ 3.5

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Represents the aggregate of total long-term debt, including current maturities and short-term debt.

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Weighted average interest rate of debt outstanding.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The amount for notes payable (written promise to pay), due to related parties.

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