DEBT

9 Months Ended

Sep. 30, 2021

Convertible Notes

As of September 30, 2021, the Company had outstanding fixed-rate notes with varying maturities for an undiscounted aggregate principal amount of $1.1 billion (collectively the Notes). The Notes are senior subordinated convertible obligations, and interest is payable in arrears, semi-annually. The following table summarizes information regarding the Company’s convertible debt:


	September 30, 2021		December 31, 2020
1.25% senior subordinated convertible notes due in May 2027 (the 2027 Notes)	$	600,000	$	600,000
Unamortized discount net of deferred offering costs	(11,478)		(12,995)
2027 Notes, net	588,522		587,005

0.599% senior subordinated convertible notes due in August 2024 (the 2024 Notes)	495,000		495,000
Unamortized discount net of deferred offering costs	(5,429)		(6,860)
2024 Notes, net	489,571		488,140

Total convertible debt, net	$	1,078,093	$	1,075,145

Fair value of fixed rate convertible debt (1):
2027 Notes	$	600,858	$	627,090
2024 Notes	510,954		530,714
Total fair value of fixed rate convertible debt	$	1,111,812	$	1,157,804

(1) The fair value of the Company’s fixed-rate convertible debt is based on open market trades and is classified as Level 1 in the fair value hierarchy. For additional discussion of fair value measurements, see Note 3 – Summary of Significant Accounting Policies included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Interest expense on the Company’s convertible debt consisted of the following:


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Coupon interest expense	$	2,617	$	4,255	$	7,849	$	9,443
Accretion of discount on convertible notes	835		4,696		2,503		13,201
Amortization of debt issuance costs	148		535		445		1,565
Total interest expense on convertible debt	$	3,600	$	9,486	$	10,797	$	24,209

See Note 13 - Debt included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 for additional information related to the Company’s convertible debt.

Revolving Credit Facility

In October 2018, the Company entered into an unsecured revolving credit facility of up to $200.0 million which includes a letter of credit subfacility and a swingline loan subfacility. The credit facility is intended to finance ongoing working capital needs and for other general corporate purposes. In May 2021, the Company entered into an amendment agreement in respect of the credit facility, extending the maturity date from October 19, 2021 to May 28, 2024, among other changes. The amended credit facility contains financial covenants including a maximum leverage ratio and a minimum interest coverage ratio. As of September 30, 2021, there were no amounts outstanding under the credit facility and the Company and certain of its subsidiaries that serve as guarantors were in compliance with all covenants.