LONG-TERM DEBT, LETTERS OF CREDIT AND DERIVATIVES - Components of Convertible Debt Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Debt Instrument [Line Items]
Amortization of debt discount and issuance costs	$ 2,055	$ 1,860
Interest expense, net	6,776	7,425
Convertible debt
Debt Instrument [Line Items]
Coupon interest	2,875	2,875
Amortization of debt discount and issuance costs	1,707	1,561
Interest expense, net	$ 4,582	$ 4,436
Effective interest rate	9.12%	9.12%

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
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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 the cost of borrowed funds accounted for as interest expense for debt.

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

+ References

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