3. Restricted Marketable Securities (Details) - Available For Sale - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 48,072	$ 52,562
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	713
Restricted marketable securities	202,497	217,172
Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	260,964	264,278
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	72	59
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	58,539	47,165
Restricted marketable securities	$ 202,497	217,172
Minimum [Member] \| Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Contractual maturities of Debt securities, Available-for-sale, range start (in years)	4 years
Maximum [Member] \| Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Contractual Maturities Of Debt securities, Available-for-sale, Range End (In Years)	13 years
U.S. debt [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		10,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		713
U.S. debt [Member] \| Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 141,374	142,790
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	34,244	27,440
Restricted marketable securities	107,130	115,350
Foreign government obligations [Member] \| Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	65,431	67,091
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	14,941	12,935
Restricted marketable securities	50,490	54,156
Supranational debt [Member] \| Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	29,957	30,123
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	72	59
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2,711	1,906
Restricted marketable securities	27,318	28,276
U.S. government obligations [Member] \| Restricted Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	24,202	24,274
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	6,643	4,884
Restricted marketable securities	$ 17,559	$ 19,390

Contractual Maturities Of Debt securities, Available-for-sale, Range End (In Years)

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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