DEBT - Components of Long-term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Line of Credit Facility
Principal amount	$ 494,474	$ 495,824
Less: Unamortized debt financing costs	(11,648)	(13,094)
Less: Current portion	(79,522)	(69,747)
Long-term debt, net	403,304	412,983
Secured Debt \| $495 Million Credit Facility
Line of Credit Facility
Principal amount	373,654	395,724
Less: Unamortized debt financing costs	(9,941)	(11,642)
Secured Debt \| $133 Million Credit Facility
Line of Credit Facility
Principal amount	120,820	100,100
Less: Unamortized debt financing costs	$ (1,707)	$ (1,452)

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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Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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

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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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