Note 3 - Marketable Securities - Amortized Costs and Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Securities, Amortized cost	$ 154,553	$ 182,746
Securities, Gains	190	246
Securities, Losses	(43)	(175)
Securities, Fair Value	154,700	182,817
US Government Agencies Debt Securities [Member]
Securities, Amortized cost	55,740	57,232
Securities, Gains	91	57
Securities, Losses	(27)	(134)
Securities, Fair Value	55,804	57,155
Certificates of Deposit [Member]
Securities, Amortized cost	6,199	8,519
Securities, Gains	2	6
Securities, Losses	(1)	(1)
Securities, Fair Value	6,200	8,524
Corporate Debt Securities [Member]
Securities, Amortized cost	67,326	80,751
Securities, Gains	57	110
Securities, Losses	(13)	(39)
Securities, Fair Value	67,370	80,822
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Securities, Amortized cost	10,609	22,265
Securities, Gains	4	11
Securities, Losses	(1)	(1)
Securities, Fair Value	10,612	22,275
Debt Security, Government, Non-US [Member]
Securities, Amortized cost	2,336	2,145
Securities, Gains	1	1
Securities, Losses	(1)	0
Securities, Fair Value	2,336	2,146
Asset-Backed Securities [Member]
Securities, Amortized cost	12,343	11,834
Securities, Gains	35	61
Securities, Losses	0	0
Securities, Fair Value	$ 12,378	$ 11,895

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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