Debt (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Short-term borrowings	$ 8.1	$ 14.2
Long-term Debt Types [Abstract]
Total long-term debt	2,837.5	2,471.5
Total Debt	2,845.6	2,485.7
Long-term Debt by Current and Noncurrent [Abstract]
Current liabilities	144.5	151.5
Noncurrent liabilities	2,701.1	2,334.2
Term Loan A \| Senior Secured Credit Facility - Amended II
Long-term Debt Types [Abstract]
Long-term Debt	1,241.6	1,292.4
Other Disclosures [Abstract]
Debt issue costs	4.1	5.4
Senior unsecured notes \| Six hundred million senior unsecured notes
Long-term Debt Types [Abstract]
Long-term Debt	989.2	987.5
Other Disclosures [Abstract]
Debt issue costs	10.8	12.5
Revolving Credit Facility
Long-term Debt Types [Abstract]
Debt	381.8	0.0
Other Non-US Dollar-denominated Facilities
Long-term Debt Types [Abstract]
Debt	58.2	40.2
Financing leases
Long-term Debt Types [Abstract]
Financing leases	166.7	151.4
Short-term borrowings
Debt Instrument [Line Items]
Short-term borrowings	$ 8.1	$ 14.2

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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Present value of lessee's discounted obligation for lease payments from finance lease.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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

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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 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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