Convertible Senior Notes (Tables)

6 Months Ended

Jun. 30, 2020

2027 Notes

Convertible Senior Notes

Summary of the Notes

The 2027 Notes consist of the following (in thousands):

	As of June 30,
Liability component	2020
Principal	$	1,000,000
Less: Debt discount, net (1)		(305,639)
Net carrying amount	$	694,361

(1) Included in the accompanying consolidated balance sheet within convertiable senior notes and amortized to interest expense over the expected life of the 2027 Notes using the effective interest rate method.

Schedule of total interest expense recognized related to the Notes

The following table sets forth total interest expense recognized related to the 2027 Notes (in thousands):

	Six Months Ended
	June 30,
	2020
Contractual interest expense	$	1,493
Amortization of debt discount		4,033
Total	$	5,526
Effective interest rate of the liability component		7.0	%

2025 Notes

Convertible Senior Notes

Summary of the Notes

The 2025 Notes consist of the following (in thousands):

	As of June 30,		As of December 31,
Liability component	2020		2019
Principal	$	287,500	$	287,500
Less: Debt discount, net (2)		(74,989)		(81,207)
Net carrying amount	$	212,511	$	206,293

(2) Included in the accompanying consolidated balance sheets within convertible senior notes and amortized to interest expense over the expected life of the 2025 Notes using the effective interest rate method.

Schedule of total interest expense recognized related to the Notes

The following table sets forth total interest expense recognized related to the 2025 Notes (in thousands):

	Quarters Ended						Six Months Ended
	June 30,						June 30,
	2020			2019			2020			2019
Contractual interest expense	$	989		$	1,002		$	1,977		$	1,977
Amortization of debt discount		3,142			2,892			6,218			5,728
Total	$	4,131		$	3,894		$	8,195		$	7,705
Effective interest rate of the liability component		7.9	%		7.9	%		7.9	%		7.9	%

2022 Notes

Convertible Senior Notes

Summary of the Notes

The 2022 Notes consist of the following (in thousands):

	As of June 30,		As of December 31,
Liability component	2020		2019
Principal	$	46,771	$	274,995
Less: Debt discount, net (3)		(5,465)		(40,878)
Net carrying amount	$	41,306	$	234,117

(3) Included in the accompanying consolidated balance sheets within convertible senior notes and amortized to interest expense over the expected life of the 2022 Notes using the effective interest rate method.

Schedule of total interest expense recognized related to the Notes

The following table sets forth total interest expense recognized related to the 2022 Notes (in thousands):

	Quarters Ended						Six Months Ended
	June 30,						June 30,
	2020			2019			2020			2019
Contractual interest expense	$	1,286		$	2,091		$	3,349		$	4,125
Amortization of debt discount		2,521			3,412			6,281			6,786
Total	$	3,807		$	5,503		$	9,630		$	10,911
Effective interest rate of the liability component		10.0	%		10.0	%		10.0	%		10.0	%