3. Restricted Marketable Securities (Tables)

9 Months Ended

Sep. 30, 2024

Debt Securities, Available-for-Sale, Restricted [Abstract]

Schedule of Restricted Marketable Securities

Restricted marketable securities consisted of the following as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30, 2024		December 31, 2023
Foreign government obligations	$	52,368	$	51,229
Supranational debt	23,350		15,339
U.S. debt	116,157		113,326
U.S. government obligations	19,255		18,416
Total restricted marketable securities	$	211,130	$	198,310

Restricted Available-for-sale Marketable Securities

The following tables summarize the unrealized gains and losses related to our restricted marketable securities, by major security type, as of September 30, 2024 and December 31, 2023 (in thousands):


	As of September 30, 2024
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
Foreign government obligations	$	65,336	$	—	$	12,968	$	—	$	52,368
Supranational debt	25,405		3		2,058		—		23,350
U.S. debt	145,113		—		28,956		—		116,157
U.S. government obligations	24,391		—		5,136		—		19,255
Total	$	260,245	$	3	$	49,118	$	—	$	211,130


	As of December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized Losses		Allowance for Credit Losses		Fair Value
Foreign government obligations	$	65,202	$	—	$	13,963	$	10	$	51,229
Supranational debt	17,688		—		2,349		—		15,339
U.S. debt	146,484		—		33,129		29		113,326
U.S. government obligations	24,460		—		6,039		5		18,416
Total	$	253,834	$	—	$	55,480	$	44	$	198,310