Debt - Components of debt (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Term Loan	$ 150.0
Financing leases	7.2	$ 7.3
Long-term Debt and Lease Obligation, Including Current Maturities	357.2	107.3
Less: unamortized debt issuance costs	(0.3)	0.0
Total debt	356.9	107.3
Term Loan
Debt Instrument [Line Items]
Term Loan	150.0	0.0
Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Revolving credit facility	200.0	$ 100.0
Less: unamortized debt issuance costs	$ (1.9)

Line of Credit Facility, Amount Outstanding Exclusive of Letters of Credit

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Amount of short-term and long-term debt and lease obligation.

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- Definition

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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of long-term debt and lease obligation, including portion classified as current.

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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