Financial Instruments and Fair Value Disclosures (Tables)

6 Months Ended

Jun. 30, 2024

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Assets and Liabilities Measured at Fair Value on Recurring Basis

Assets and liabilities measured at fair value are summarized below (in thousands).

	June 30, 2024
	Fair Value Measurements Using
	Level 1			Level 2		Level 3		Assets (Liabilities) at Fair Value			Total Losses for Six Months Ended (2)
Recurring fair value measurements:
Short-term investments (1)	$	79,866		$	—	$	—	$	79,866		$	—
Liability-classified restricted stock units (2)	$	(1,511	)	$	—	$	—	$	(1,511	)	$	(243	)

	December 31, 2023
	Fair Value Measurements Using
	Level 1			Level 2		Level 3		Assets (Liabilities) at Fair Value			Total Losses for Year Ended (2)
Recurring fair value measurements:
Short-term investments (1)	$	92,308		$	—	$	—	$	92,308		$	—
Liability-classified restricted stock units (2)	$	(1,259	)	$	—	$	—	$	(1,259	)	$	(252	)

(1)Represents short-term investments, with original maturities of three months or less, in debt securities classified as available for sale.

(2)The fair value of restricted stock units was estimated based on the quoted market price of our common stock at the respective balance sheet date. The total loss for the period or year includes an increase in stock compensation expense due to the “marking-to-market” of liability-classified restricted stock units granted to our non-employee directors on a recurring basis.

Fair Values and Related Carrying Values of Our Debt Instruments

Fair values and related carrying values of our Second Lien Notes (as defined below in Note 6 “Long-Term Debt”) are shown below (in millions).

	June 30, 2024				December 31, 2023
	Fair Value		Carrying Value		Fair Value		Carrying Value
Second Lien Notes	$	575.2	$	550.0	$	562.6	$	550.0