DEBT (Tables)

6 Months Ended

Jun. 30, 2020

The following table summarizes information regarding the Company’s convertible debt:


	June 30, 2020		December 31, 2019
1.25% senior subordinated convertible notes due in May 2027 (the 2027 Notes)	$	600,000	$	—
Unamortized discount	(13,269)		—
Unamortized deferred offering costs	(717)		—
2027 Notes, net	586,014		—

0.599% senior subordinated convertible notes due in August 2024 (the 2024 Notes)	495,000		495,000
Unamortized discount	(5,825)		(6,533)
Unamortized deferred offering costs	(1,987)		(2,229)
2024 Notes, net	487,188		486,238

1.50% senior subordinated convertible notes due in October 2020 (the 2020 Notes)	374,993		374,993
Unamortized discount	(4,512)		(12,078)
Unamortized deferred offering costs	(381)		(1,033)
2020 Notes, net⁽¹⁾	370,100		361,882

Total convertible debt, net	$	1,443,302	$	848,120

Fair value of fixed rate convertible debt ⁽²⁾:
2027 Notes	$	702,882	$	—
2024 Notes	609,216		512,582
2020 Notes	493,551		420,727
Total fair value of fixed rate convertible debt	$	1,805,649	$	933,309

(1) The 2020 Notes are classified as a current liability in the periods presented since they mature in October 2020.

(2) 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, 2019.

Summary of Interest Expense on Debt

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


	Three Months Ended June 30,						Six Months Ended June 30,
	2020		2019		2020		2019
Accretion of discount on convertible notes	$	4,395	$	3,953	$	8,505	$	7,855
Coupon interest expense	3,016		2,254		5,188		4,411
Amortization of debt issuance costs	522		508		1,030		1,015
Total interest expense on convertible debt	$	7,933	$	6,715	$	14,723	$	13,281