DEBT - Schedule of Outstanding Debt Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Net carrying amount	$ 277,034	$ 283,209
Less: current maturities	0	21,276
Long-term debt, net of current maturities	277,034	261,933
Convertible Debt \| 2022 Convertible Notes
Debt Instrument [Line Items]
Net carrying amount	277,034	261,933
Convertible Debt \| 2019 Convertible Notes
Debt Instrument [Line Items]
Net carrying amount	$ 0	$ 21,276

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No definition available.

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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, 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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