Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2023

Financial Instruments

Schedule of available-for-sale securities

	September 30, 2023						December 31, 2022
	Amortized Cost		Gross Unrealized Loss		Estimated Fair Value		Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Estimated Fair Value
	(in thousands)
Cash, cash equivalents and restricted cash (2)	$	668,710	$	—	$	668,710	$	466,091	$	—	$	—	$	466,091
U.S. Treasury securities (1)		227,276		(2,833)		224,443		358,385		—		(12,328)		346,057
Corporate bonds and notes (1)		4,000		(24)		3,976		24,045		—		(516)		23,529
Municipal securities (1)		41,701		(2,273)		39,428		65,973		1		(3,259)		62,715
Total	$	941,687	$	(5,130)	$	936,557	$	914,494	$	1	$	(16,103)	$	898,392
Classified as:
Cash, cash equivalents and restricted cash (2)						668,710								466,091
Short-term investments						267,847								432,301
Total					$	936,557							$	898,392

(1) Per the Company’s investment policy, all debt securities are classified as short-term investments irrespective of holding period.  

(2) Cash equivalents includes money market deposits and liquid demand deposits.

Schedule of debt securities available-for-sale in unrealized loss position

	Total
	Fair Value		Unrealized Loss
	(in thousands)
U.S. Treasury securities	$	224,443	$	(2,833)
Corporate bonds and notes		3,976		(24)
Municipal securities		39,428		(2,273)
Total	$	267,847	$	(5,130)

Summarized portfolio of available-for-sale securities by contractual maturity

	September 30, 2023
	Amortized Cost		Fair Value
	(in thousands)
Less than or equal to one year	$	242,845	$	239,773
Greater than one year but less than five years		30,132		28,074
Total	$	272,977	$	267,847