Note 4 - Marketable Securities - Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Amortized Cost	$ 173,409	$ 83,029
Unrealized gains	281	230
Unrealized Losses	(7)	(20)
Fair Value	173,683	83,239
Marketable Securities	173,683	83,239
Corporate Debt Securities [Member]
Amortized Cost	83,437	44,794
Unrealized gains	240	175
Unrealized Losses	(3)	(6)
Fair Value	83,674	44,963
Marketable Securities	83,674	44,963
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Amortized Cost	71,375	12,081
Unrealized gains	23	5
Unrealized Losses	(3)	(2)
Fair Value	71,395	12,084
Marketable Securities	71,395	12,084
Certificates of Deposit [Member]
Amortized Cost	13,189	15,262
Unrealized gains	6	8
Unrealized Losses	(1)	(1)
Fair Value	13,194	15,269
Marketable Securities	13,194	15,269
US Treasury Securities [Member]
Amortized Cost	1,678	4,408
Unrealized gains	0	2
Unrealized Losses	0	(11)
Fair Value	1,678	4,399
Marketable Securities	1,678	4,399
Asset-Backed Securities [Member]
Amortized Cost	3,730	6,484
Unrealized gains	12	40
Unrealized Losses	0	0
Fair Value	3,742	6,524
Marketable Securities	$ 3,742	$ 6,524