Debt (Tables)

6 Months Ended

Jun. 30, 2022

Debt

Summary of Convertible Senior Notes

The following is a summary of our convertible senior notes at June 30, 2022 and December 31, 2021 (principal amount in thousands):

	Principal Amount		Principal Amount				Conversion rate per $1,000
	June 30, 2022		December 31, 2021		Interest Rate	Maturity Date	principal amount (shares)
2024 Notes (2019 Issuance)		85,782		85,782	4.50%	August 1, 2024	137.2213
2024 Notes (2020 Issuance)		57,500		57,500	4.50%	August 1, 2024	160.3334
2025 Notes		300,000		300,000	1.25%	May 1, 2025	13.1278
Total		443,282		443,282
Unamortized debt issuance costs		(5,482)		(6,510)
Convertible senior notes	$	437,800	$	436,772

Schedule of Maturities of Convertible Notes

Maturities of our convertible notes consisted of the following as of June 30, 2022 (in thousands):

2022 (remaining six months)	$	—
2023		—
2024		143,282
2025		300,000
2026		—
Thereafter		—
		443,282
Less debt issuance costs		(5,482)
Current portion		—
Long-term portion	$	437,800

Schedule of expected maturities of Finance Agreement

2022 (remaining six months)	$	8,500
2023		34,000
2024		34,000
2025		88,699
2026		34,000
Thereafter		131,198
		330,397
Less debt issuance costs		(1,186)
Less unrecognized interest		(120,127)
Current portion		(25,500)
Long-term portion	$	183,584

Schedule of Total Interest Expense Recognized Related to Notes

The following table sets forth total interest expense recognized during the three and six months ended June 30, 2022 and 2021 (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2022		2021		2022		2021
Interest on convertible notes	$	2,549	$	2,952	$	5,099	$	5,929
Amortization of debt issuance costs		562		622		1,119		1,260
Interest on finance lease		—		178		—		363
Interest on borrowings under financing agreement		6,563		4,993		12,556		9,203
Other interest		—		25		—		52
Total interest expense	$	9,674	$	8,770	$	18,774	$	16,807