DEBT - Interest Expense (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
Feb. 29, 2020	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Weighted-average effective interest rate		1.20%	4.30%
Convertible debt
Debt Instrument [Line Items]
Interest rate	0.75%
Contractual interest expense (0.75% coupon)		$ 1,125	$ 450
Amortization of debt discount		0	1,497
Amortization of issuance costs		673	222
Interest expense		$ 1,798	$ 2,169

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of amortization expense attributable to debt issuance costs.

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The rate of interest that was being paid on the original debt issue that is being converted in the noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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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.

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