Note 5 - Investments, Available-for-sale

3 Months Ended

Mar. 31, 2022

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 unrealized gains and losses determined on an individual investment security basis and included in other comprehensive loss are as follows:

	March 31, 2022
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial Paper	$	44,124	$	-	$	(191	)	$	43,933	$	43,933	$	-
Corporate Bonds		50,314		-		(607	)		49,707		34,980		14,727
Total Investments	$	94,438	$	-	$	(798	)	$	93,640	$	78,913	$	14,727

	December 31, 2021
	(in thousands)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value		Short-term investments		Long-term investments
Commercial Paper	$	50,705	$	-	$	(46	)	$	50,659	$	50,660	$	-
Corporate Bonds		67,239		1		(202	)		67,038		29,602		37,435
Total Investments	$	117,944	$	1	$	(248	)	$	117,697	$	80,262	$	37,435

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

	March 31, 2022
	(in thousands)
	Amortized Cost		Fair Value
Mature in less than one year	$	79,453	$	78,913
Mature in one to two years		14,985		14,727
Total	$	94,438	$	93,640

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 or gross realized gains or losses for the three months ended March 31, 2022, and 2021, respectively.