FINANCING ARRANGEMENTS - Schedule of Notes (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Apr. 04, 2016
Debt Instrument [Line Items]
Principal amount	$ 250,000	$ 250,000
Less: debt discount	(24,307)	(35,131)	$ (4,800)
Net carrying amount of liability component	225,693	214,869
Additional Paid-in Capital
Debt Instrument [Line Items]
Net carrying amount of equity component	$ 67,014	$ 67,014

Carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Convertible Notes Payable, excluding current portion. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

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The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

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Face (par) amount of debt instrument at time of issuance.

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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 accumulated amortization, of debt discount.

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