Note 5 - Investments, Available-for-sale

12 Months Ended

Dec. 31, 2023

Notes to Financial Statements

Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]

5. Investments, available-for-sale

The aggregate fair values of investment securities along with cumulative unrealized gains and losses determined on an individual investment security basis and included in other comprehensive loss are as follows:

	December 31, 2023
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments
					(in thousands)
Corporate bonds	$	3,981	$	-	$	(10	)	$	3,971	$	3,971
Total investments	$	3,981	$	-	$	(10	)	$	3,971	$	3,971

	December 31, 2022
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
					(in thousands)
Commercial paper	$	12,364	$	-	$	(49	)	$	12,315	$	12,315	$	-
Corporate bonds		55,201		-		(447	)		54,754		50,889		3,865
U.S. government agencies		999		-		(8	)		991		991		-
Total investments	$	68,564	$	-	$	(504	)	$	68,060	$	64,195	$	3,865

The following table summarizes the contractual maturities of the Company’s available-for-sale investments:

	December 31, 2023
	Amortized Cost		Fair Value
	(in thousands)
Mature in less than one year	$	3,981	$	3,971
Total	$	3,981	$	3,971

Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay certain obligations. There were no sales of investments for the years ended December 31, 2023 or 2022, respectively. There were no realized gains or losses for the years ended December 31, 2023 and 2022 respectively.