Convertible Notes (Tables)

6 Months Ended

Jun. 30, 2021

Debt Disclosure [Abstract]

Convertible Notes

The Notes at June 30, 2021 and December 31, 2020 consisted of the following (in thousands):

	June 30,		December 31,
	2021		2020
Outstanding principal	$	171,500	$	171,500
Unamortized debt discount	(22,800)		(28,524)
Unamortized debt issuance	(1,410)		(1,765)
Net carrying amount of the liability component	$	147,290	$	141,211

Schedule of Interest Expense

Interest expense for the three and six months ended June 30, 2021 and 2020 were as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Contractual coupon interest	$	1,072	$	1,072	$	2,144	$	2,144
Amortization of the debt discount	2,903		2,591		5,724		5,109
Amortization of debt issuance costs	180		160		354		316
Total interest expense on convertible notes	$	4,155	$	3,823	$	8,222	$	7,569