Fair Value Measurements

3 Months Ended

Mar. 31, 2024

The Company utilizes the market approach to measure the fair value of its financial assets. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets. The assets classified as Level 2 primarily utilize quoted market prices or alternative pricing sources including transactions involving identical or

comparable assets and models utilizing market observable inputs for valuation of these securities. No changes in valuation techniques or inputs occurred during the three months ended March 31, 2024.

Financial instruments measured at fair value on a recurring basis:


	As of March 31, 2024						As of December 31, 2023
(in thousands)	Total		Level 1		Level 2		Total		Level 1		Level 2
Cash equivalents
Commercial paper	$	45,906	$	—	$	45,906	$	19,575	$	—	$	19,575
Money market funds	31,427		31,427		—		33,613		33,613		—
US Treasury bonds	24,746		—		24,746		2,000		—		2,000
Municipal debt securities	20,004		—		20,004		7,848		—		7,848

Federal agency debt securities	12,077		—		12,077		8,201		—		8,201
Total cash equivalents	134,160		31,427		102,733		71,237		33,613		37,624
Short-term
Corporate debt securities	225,735		—		225,735		210,982		—		210,982
Commercial paper	221,827		—		221,827		237,870		—		237,870
Federal agency debt securities	140,588		—		140,588		194,522		—		194,522
Municipal debt securities	14,013		—		14,013		13,914		—		13,914
US Treasury Bonds	7,298		—		7,298		14,126		—		14,126
Certificate of deposit	7,000		—		7,000		—		—		—
Total short-term	616,461		—		616,461		671,414		—		671,414
Long-term
Corporate debt securities	39,054		—		39,054		43,869		—		43,869
Federal agency debt securities	4,745		—		4,745		12,135		—		12,135



Total long-term	43,799		—		43,799		56,004		—		56,004
Total financial instruments	$	794,420	$	31,427	$	762,993	$	798,655	$	33,613	$	765,042

None of the Company's debt is publicly held and as a result, the Company has determined the estimated fair value of these notes to be Level 3. Certain inputs used to determine fair value are unobservable and, therefore, could be sensitive to changes in inputs. The Company utilizes the discounted cash flow method to estimate the fair value of Level 3 debt.

The carrying value and estimated fair value of long-term debt, excluding finance leases, including current maturities and without reduction for related costs, are as follows:


	As of March 31, 2024				As of December 31, 2023
(in thousands)	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Hierarchy Level
Fair Value of Notes Payable	$	1,820,368	$	1,815,856	$	1,826,921	$	1,815,351	3

Due to their short-term nature, the carrying amounts of cash, restricted cash, accounts receivable and accounts payable approximate fair value.