Convertible Notes (Tables)

9 Months Ended

Sep. 30, 2019

Debt Disclosure [Abstract]

Schedule of convertible notes

The Company’s convertible notes are shown in the following table:

(In thousands)	As of September 30, 2019			As of December 31, 2018
2023 Notes	$	172,500		$	172,500
Unamortized discount - 2023 Notes	(23,786		)	(28,517		)
Unamortized debt issuance costs - 2023 Notes	(1,675		)	(2,049		)
Total convertible notes	$	147,039		$	141,934
Less current portion	—			—
Total long-term convertible notes	$	147,039		$	141,934

Schedule of interest expense on notes

Interest expense related to the notes for the three and nine months ended September 30, 2019 and 2018 was as follows:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(In thousands)	2019		2018		2019		2018
2023 Notes coupon interest at a rate of 1.375%	$	593	$	593	$	1,779	$	1,779
2023 Notes amortization of discount and debt issuance costs at an additional effective interest rate of 4.9%	1,725		1,632		5,104		4,831
2018 Notes coupon interest at a rate of 1.125%	—		96		—		377
2018 Notes amortization of discount and debt issuance costs at an additional effective interest rate of 5.5%	—		559		—		2,756
Total interest expense on convertible notes	$	2,318	$	2,880	$	6,883	$	9,743