Long-term Debt (Tables)

3 Months Ended

Mar. 31, 2020

Long-term Debt

Schedule of Future Annual Principal Payments on Convertible Senior Notes

The following is a summary of our convertible senior notes at March 31, 2020:

		Principal Amount
	Interest Rate		(in thousands)	Due Date
2021 Notes	2.50%	$	97,188	September 15, 2021
2024 Notes	4.50%		138,858	August 1, 2024
2025 Notes	1.25%		300,000	May 1, 2025
Total		$	536,046

Schedule of Total Interest Expense Recognized Related to Notes

	Three months ended March 31,
	2020		2019
Interest on convertible notes	$	3,183	$	2,734
Amortization of debt issuance costs		786		645
Debt issuance cost derecognized related to 2024 Notes		3,555		—
Interest on finance lease		215		184
Interest on borrowings under financing agreement		1,791		—
Other interest		31		27
Total interest expense	$	9,561	$	3,590