Note 3 - U.S. Treasury Securities, Available-for-sale (Tables)

3 Months Ended

Mar. 31, 2024

Notes Tables

Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]

(in thousands)
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
March 31, 2024
U.S. Treasury Bill maturing 4/30/2024	$	49,791	$	-	$	(24	)	$	49,767
U.S. Treasury Note maturing 5/31/2024		49,735		-		(6	)		49,729
	$	99,526	$	-	$	(30	)	$	99,496
December 31, 2023
U.S. Treasury Bill maturing 1/2/2024	$	49,671	$	9	$	-		$	49,680
U.S. Treasury Bill maturing 2/15/2024		49,992		8		-			50,000
U.S. Treasury Bill maturing 4/30/2024		49,140		-		-			49,140
	$	148,803	$	17	$	-		$	148,820