DEBT - DESCRIPTION (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Debt
Payment of debt financing costs	$ 18.5
Proceeds from issuance of debt	$ 325.5
Revolving Credit Facility
Debt
Interest rate during period (as a percent)	3.25%
Unused portion of credit facility	$ 518.9
Standby and commercial letters of credit
Debt
Standby letters of credit	$ 8.1
5.34%, payable through 2028
Debt
Interest rate (as a percent)	5.34%	5.34%
5.79%, payable through 2020
Debt
Interest rate (as a percent)	5.79%	5.79%
5.27%, payable through 2029
Debt
Interest rate (as a percent)	5.27%	5.27%
4.35%, payable through 2044
Debt
Interest rate (as a percent)	4.35%	4.35%

The average effective interest rate during the reporting period.

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- Definition

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

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- Definition

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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No definition available.

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- Definition

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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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- Definition

The cash outflow for loan and debt issuance costs.

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- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

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