CONVERTIBLE NOTES PAYABLE (Tables)

6 Months Ended

Jun. 30, 2021

Debt Disclosure [Abstract]

Schedule of long-term debt instruments

The composition of the Company’s 2025 Notes are as follows (in thousands):

	June 30, 2021		December 31, 2020
2.50% convertible senior notes due 2025	$	276,000	$	276,000
Unamortized debt discount	(51,314)		(56,384)
Unamortized debt issuance costs	(3,825)		(4,277)
Total 2025 Notes, net of unamortized debt discount and debt issuance costs	$	220,861	$	215,339

The effective interest rate on the liability components of the 2025 Notes for the period from the date of issuance through June 30, 2021 was 7.7%. The following table sets forth total interest expense recognized related to the 2025 Notes (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Contractual interest expense	$	1,725	$	1,725	$	3,450	$	3,450
Amortization of debt discount	2,560		2,371		5,071		4,698
Amortization of debt issuance costs	226		225		451		449
Total interest expense for the 2025 Notes	$	4,511	$	4,321	$	8,972	$	8,597