Note 3 - Investments- Fair Value of the Company's Investments by Type (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Marketable Securities [Line Items]
Amortized Cost	$ 138,196	$ 9,989
Accrued Interest	487	65
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,063)	(13)
Estimated Fair Value	$ 137,620	10,041
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Investments, Long-term investments
Obligations of U.S. Government and its agencies
Marketable Securities [Line Items]
Amortized Cost	$ 129,940	4,043
Accrued Interest	427	17
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(996)	(7)
Estimated Fair Value	129,371	4,053
Corporate debt securities
Marketable Securities [Line Items]
Amortized Cost	6,093	4,294
Accrued Interest	37	40
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(38)	(5)
Estimated Fair Value	6,092	4,329
Certificates of deposit
Marketable Securities [Line Items]
Amortized Cost	2,163	1,652
Accrued Interest	23	8
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(29)	(1)
Estimated Fair Value	$ 2,157	$ 1,659

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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