Note 7 - Available-for-Sale Securities - Summary of Company's Available-for-sale Securities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-Sale [Line Items]
Available-for-Sale Securities, Amortized Cost	$ 162,726	$ 165,387
Available-for-Sale Securities, Unrealized Gains	34	22
Available-for-Sale Securities, Unrealized Losses	(31)	(73)
Available-for-Sale Securities, Estimated Fair Value	$ 162,729	$ 165,336
Securities of U.S. Government and Government Agencies [Member]
Debt Securities, Available-for-Sale [Line Items]
Available-for-Sale Securities , Maturities	Within one year	Within two years
Available-for-Sale Securities, Amortized Cost	$ 53,959	$ 51,500
Available-for-Sale Securities, Unrealized Gains	14	13
Available-for-Sale Securities, Unrealized Losses	(12)	(13)
Available-for-Sale Securities, Estimated Fair Value	$ 53,961	$ 51,500
Commercial Paper [Member]
Debt Securities, Available-for-Sale [Line Items]
Available-for-Sale Securities , Maturities	Within one year	Within one year
Available-for-Sale Securities, Amortized Cost	$ 31,728	$ 44,480
Available-for-Sale Securities, Unrealized Gains	4	7
Available-for-Sale Securities, Unrealized Losses	(6)	(14)
Available-for-Sale Securities, Estimated Fair Value	$ 31,726	$ 44,473
Certificates of Deposit [Member]
Debt Securities, Available-for-Sale [Line Items]
Available-for-Sale Securities , Maturities	Within one year
Available-for-Sale Securities, Amortized Cost	$ 1,720
Available-for-Sale Securities, Unrealized Gains	2
Available-for-Sale Securities, Unrealized Losses	0
Available-for-Sale Securities, Estimated Fair Value	$ 1,722
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Available-for-Sale Securities , Maturities	Within one year	Within one year
Available-for-Sale Securities, Amortized Cost	$ 67,054	$ 64,615
Available-for-Sale Securities, Unrealized Gains	13	1
Available-for-Sale Securities, Unrealized Losses	(9)	(46)
Available-for-Sale Securities, Estimated Fair Value	$ 67,058	$ 64,570
Asset-backed Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Available-for-Sale Securities , Maturities	Within three years	Within four years
Available-for-Sale Securities, Amortized Cost	$ 8,265	$ 4,792
Available-for-Sale Securities, Unrealized Gains	1	1
Available-for-Sale Securities, Unrealized Losses	(4)	0
Available-for-Sale Securities, Estimated Fair Value	$ 8,262	$ 4,793

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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