Convertible Senior Notes (Tables)

12 Months Ended

Dec. 31, 2021

Summary of Debt Obligations

The following table summarizes the Company’s debt obligations at December 31, 2021 (in thousands):

	Less than 1 Year		1 to 3 Years		3 to 5 Years		More than 5 Years		Total
Debt obligations	$	8	$	450,000	$	375,000	$	—	$	825,008

0% Convertible Senior Notes Due 2026

Schedule of Components of Convertible Senior Notes

The 2026 Notes consist of the following (in thousands):

	As of December 31, 2021
Liability component:
Principal	$	375,000
Less: debt discount, net of amortization		(97,261	)
Net carrying amount	$	277,739
Equity component (1)		99,000

⁽¹⁾ Recorded in the consolidated balance sheet within additional paid-in capital, net of $3.0 million transaction costs in equity and net of $3.4 million for taxes.

Summary of Total Interest Expense Recognized Related To Convertible Senior Notes

The following table sets forth total interest expense recognized related to the 2026 Notes (in thousands):

	Year Ended December 31, 2021
Amortization of debt discount and transaction costs	$	15,715

Summary of Fair Value and Carrying Value of Convertible Senior Notes

The fair value of the 2026 Notes, which was determined based on inputs that are observable in the market or that could be derived from, or corroborated with, observable market data, quoted price of the 2026 Notes in an over-the-counter market (Level 2), and carrying value of debt instruments (carrying value excludes the equity component of the Company’s 2026 Notes classified in equity) was as follows (in thousands):

	As of December 31, 2021
	Fair Value		Carrying Value
2026 Notes	$	318,311	$	277,739

0.125% Convertible Senior Notes Due 2024

Schedule of Components of Convertible Senior Notes

The 2024 Notes consist of the following (in thousands):

	As of December 31,
	2021			2020
Liability component:
Principal	$	450,000		$	450,000
Less: debt discount, net of amortization		(62,044	)		(80,968	)
Net carrying amount	$	387,956		$	369,032
Equity component (1)		86,133			86,133

^{(1) Recorded in the consolidated balance sheet within additional paid-in capital, net of $2.6 million transaction costs in equity and net of $0.9 million for taxes.}

Summary of Total Interest Expense Recognized Related To Convertible Senior Notes

The following table sets forth total interest expense recognized related to the 2024 Notes (in thousands):

	Year Ended December 31,
	2021		2020		2019
0.125% coupon	$	562	$	564	$	27
Amortization of debt discount and transaction costs		18,924		17,974		827
	$	19,486	$	18,538	$	854

Summary of Fair Value and Carrying Value of Convertible Senior Notes

The fair value of the 2024 Notes, which was determined based on inputs that are observable in the market or that could be derived from, or corroborated with, observable market data, quoted price of the 2024 Notes in an over-the-counter market (Level 2), and carrying value of debt instruments (carrying value excludes the equity component of the Company’s 2024 Notes classified in equity) were as follows (in thousands):

	As of December 31,
	2021				2020
	Fair Value		Carrying Value		Fair Value		Carrying Value
2024 Notes	$	440,564	$	387,956	$	663,615	$	369,032

1.50% Convertible Senior Notes Due 2022

Schedule of Components of Convertible Senior Notes

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

	As of December 31,
	2021			2020
Liability component:
Principal	$	8		$	79,795
Less: debt discount, net of amortization		—			(7,313	)
Net carrying amount	$	8		$	72,482
Equity component (1)		(39,358	)		(21,318	)

⁽¹⁾ Recorded in the consolidated balance sheet within additional paid-in capital, net of $0.8 million transaction costs in equity. Additional paid-in capital also includes $2.7 million and $36.7 million, respectively, market premium representing the excess of the total consideration delivered over the fair value of the liability recognized related to the $58.6 million and $23.0 million, respectively, principal balance extinguishment of the 2022 Notes in March 2021 and December 2019.  

Summary of Total Interest Expense Recognized Related To Convertible Senior Notes

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

	Year Ended December 31,
	2021		2020		2019
1.50% coupon	$	110	$	1,363	$	1,709
Amortization of debt discount and transaction costs		632		4,187		4,884
	$	742	$	5,550	$	6,593

Summary of Fair Value and Carrying Value of Convertible Senior Notes

The fair value of the 2022 Notes, which was determined based on inputs that are observable in the market or that could be derived from, or corroborated with, observable market data, quoted price of the 2022 Notes in an over-the-counter market (Level 2), and carrying value of debt instruments (carrying value excludes the equity component of the Company’s convertible notes classified in equity) were as follows (in thousands):

	As of December 31,
	2021				2020
	Fair Value		Carrying Value		Fair Value		Carrying Value
2022 Notes	$	16	$	8	$	265,488	$	72,482