Note 8 - Available-for-Sale Securities (Details Textual)	12 Months Ended
	Dec. 31, 2025 USD ($) AvailableForSaleSecurity	Dec. 31, 2024 USD ($)
Schedule of Held-to-Maturity Securities [Line Items]
Credit allowance	$ 0	$ 0
Accrued interest receivable on available-for-sale securities		200,000
Short-term investments, amortized cost	$ 114,000,000	165,387,000
Available-for-sale securities, that were in a gross unrealized loss position for less than 12 months | AvailableForSaleSecurity	10
Short-term investments, gross unrealized loss	$ 4,000	73,000
Available-for-sale securities, fair value	114,108,000	165,336,000
Available-for-sale securities that were in a gross unrealized loss position for less than 12 months, fair value	$ 6,000,000
Available-for-sale securities, that were in a gross unrealized loss position for than 12 months or more | AvailableForSaleSecurity	0
Available-for sale securities, accrued interest writeoff	$ 0	0
Available-for-sale securities, realized gains or losses	$ 0	$ 0