v3.24.3
Convertible Notes
 9 Months Ended
Sep. 30, 2024
Debt Disclosure [Abstract]  
Convertible Notes Convertible Notes
Except as described below the Company’s convertible notes are described in Note 10 of the “Notes to Consolidated Financial Statements” in the Annual Report.
The convertible notes consisted of the following (in thousands):
 September 30, 2024December 31, 2023
Principal amount$316,250 $316,250 
Unamortized debt discount and issuance costs(8,584)(9,829)
Net carrying amount$307,666 $306,421 
The Company incurred $10.9 million of transaction costs related to the issuance of the 4.00% Convertible Senior Notes due 2029 (the “Notes”), which are being amortized to interest expense over the term of the Notes using the effective interest method. As of September 30, 2024, the remaining amortization period of the debt discount was
approximately 4.6 years and the effective interest on the Notes was 4.6%. The following table sets forth interest expense recognized related to the Notes (in thousands):
Three Months Ended September 30,Nine Months Ended September 30,
 2024202320242023
Coupon interest expense$3,162 $3,163 $9,487 $5,764 
Amortization of debt discount and issuance costs424 411 1,245 718 
Total interest expense on convertible notes$3,586 $3,574 $10,732 $6,482 
As of September 30, 2024 and December 31, 2023, the estimated fair value of the Notes was $466.2 million and $387.3 million, respectively. The fair values were determined based on the quoted price of the convertible notes in an inactive market on the last trading day of the reporting period and have been classified as Level 2 in the fair value hierarchy.