Convertible Senior Notes (Tables)

12 Months Ended

Dec. 31, 2024

6.0% Convertible Debenture

Convertible Senior Notes

Schedule of change in carrying amount of convertible debt

The change in the carrying amount of the 6.00% Convertible Debenture for the year ended December 31, 2024 was as follows (in thousands):

	December 31, 2024
Principal received at issuance	$	190,000
Payments of principal settled in cash		(22,500)
Payments or principal settled in common stock		—
Loss on debt extinguishment		1,613
Change in fair value of the convertible senior note		3,424
Amortization of discount		613
Ending balance as of December 31, 2024	$	173,150

Schedule of debt

The following table summarizes the total interest expense and effective interest rate related to the 6.00% Convertible Debenture for the year ended December 31, 2024 (in thousands, except for the effective interest rate):

	Year ended
	December 31, 2024
Interest expense	$	1,596
Amortization of discount		613
Total	$	2,209
Effective interest rate		8.7	%

7.0% Convertible Senior Notes

Convertible Senior Notes

Schedule of Convertible Senior Notes

The 7.00% Convertible Senior Notes consisted of the following (in thousands):

	December 31, 2024
Principal amounts:
Principal	$	140,396
Unamortized debt premium, net of offering costs(1)		7,514
Net carrying amount	$	147,910

(1) Included in the consolidated balance sheets within convertible senior notes, net and amortized over the remaining life of the notes using the effective interest rate method.

Schedule of debt

The following table summarizes the total interest expense and effective interest rate related to the 7.00% Convertible Senior Notes for the year ended December 31, 2024 (in thousands, except for the effective interest rate):

	Year ended
	December 31, 2024
Interest expense	$	7,687
Amortization of premium		(4,085)
Total	$	3,602
Effective interest rate		3.0	%

3.75% Convertible Senior Notes

Convertible Senior Notes

Schedule of Convertible Senior Notes

The 3.75% Convertible Senior Notes consisted of the following (in thousands):

	December 31, 2024		December 31, 2023
Principal amounts:
Principal	$	58,462	$	197,278
Unamortized debt issuance costs(1)		(189)		(2,014)
Net carrying amount	$	58,273	$	195,264

(1) Included in the consolidated balance sheets within the 3.75% Convertible Senior Notes, net and amortized over the remaining life of the notes using the effective interest rate method.

Schedule of debt

The following table summarizes the total interest expense and effective interest rate related to the 3.75% Convertible Senior Notes for the year ended December 31, 2024 (in thousands, except for effective interest rate):

	Year ended
	December 31, 2024			December 31, 2023			December 31, 2022
Interest expense	$	3,335		$	7,546		$	7,398
Amortization of debt issuance costs		642			1,345			1,286
Total	$	3,977		$	8,891		$	8,684
Effective interest rate		4.5	%		4.6	%		4.5	%