Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2024

Fair Value Disclosures [Abstract]

Components of Long-Term Debt and Methods Used in Estimating Fair Values

The following table summarizes components of the Company’s long-term debt and methods used in estimating their fair values:

	Maturity Date	Valuation Methodology
4.75% Convertible Senior Notes	2042	Quoted price
4.25% Convertible Senior Notes	*	Quoted price
4.55% Promissory Note	2036	Discounted cash flow method/Level 3 inputs
5.50% Promissory Note	2033	Discounted cash flow method/Level 3 inputs

* Debt derecognized in March 2024. See Note 10 -- “Long-Term Debt” for additional information.

Assets Measured at Estimated Fair Value on a Recurring Basis

The following tables present information about the Company’s financial assets measured at estimated fair value on a recurring basis. The tables indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair value as of June 30, 2024 and December 31, 2023:

	Fair Value Measurements Using
	(Level 1)		(Level 2)		(Level 3)		Total
As of June 30, 2024
Financial Assets:
Cash and cash equivalents	$	445,829	$	—	$	—	$	445,829
Restricted cash	$	3,303	$	—	$	—	$	3,303
Fixed-maturity securities:
U.S. Treasury and U.S. government agencies	$	602,042	$	7,935	$	—	$	609,977
Corporate bonds		23,339		6,453		—		29,792
Exchange-traded debt		473		—		—		473
Total available-for-sale securities	$	625,854	$	14,388	$	—	$	640,242
Equity securities	$	53,886	$	—	$	—	$	53,886

	Fair Value Measurements Using
	(Level 1)		(Level 2)		(Level 3)		Total
As of December 31, 2023
Financial Assets:
Cash and cash equivalents	$	536,478	$	—	$	—	$	536,478
Restricted cash	$	3,287	$	—	$	—	$	3,287
Fixed-maturity securities:
U.S. Treasury and U.S. government agencies	$	348,145	$	7,909	$	—	$	356,054
Corporate bonds		20,267		6,437		—		26,704
Exchange-traded debt		480		—		—		480
Total available-for-sale securities	$	368,892	$	14,346	$	—	$	383,238
Equity securities	$	45,537	$	—	$	—	$	45,537

Schedule of Fair Value Information for Financial Liabilities Carried on Balance Sheet

The following tables present fair value information for financial liabilities that are carried on the consolidated balance sheets at amounts other than fair value as of June 30, 2024 and December 31, 2023:

	Carrying		Fair Value Measurements Using						Estimated
	Value		(Level 1)		(Level 2)		(Level 3)		Fair Value
As of June 30, 2024
Financial Liabilities:
Revolving credit facility	$	48,000	$	—	$	48,000	$	—	$	48,000
Long-term debt:
4.75% Convertible Senior Notes	$	168,806	$	—	$	224,909	$	—	$	224,909
5.50% Promissory Note		11,600		—		—		11,290		11,290
4.55% Promissory Note		4,504		—		—		4,180		4,180
Total long-term debt	$	184,910	$	—	$	224,909	$	15,470	$	240,379

	Carrying		Fair Value Measurements Using						Estimated
	Value		(Level 1)		(Level 2)		(Level 3)		Fair Value
As of December 31, 2023
Financial Liabilities:
Long-term debt:
4.75% Convertible Senior Notes	$	168,230	$	—	$	215,114	$	—	$	215,114
4.25% Convertible Senior Notes		23,916		—		34,545		—		34,545
5.50% Promissory Note		11,707		—		—		11,512		11,512
4.55% Promissory Note		4,640		—		—		4,349		4,349
Total long-term debt	$	208,493	$	—	$	249,659	$	15,861	$	265,520