Note 4 - Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2023

Notes Tables

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Carrying		Fair Value Measurement at June 30, 2023
	Value		Level 1		Level 2		Level 3
	(Unaudited - In thousands)
Cash and cash equivalents	$	14,246	$	14,246	$	—	$	—
Restricted cash	$	25	$	25	$	—	$	—
Marketable securities—held-to-maturity:
U.S. Government securities	$	841	$	841	$	—	$	—

	Carrying		Fair Value Measurement at December 31, 2022
	Value		Level 1		Level 2		Level 3
	(Unaudited - In thousands)
Cash and cash equivalents	$	13,331	$	13,331	$	—	$	—
Restricted cash	$	25	$	25	$	—	$	—
Marketable securities—held-to-maturity:
U.S. Government securities	$	5,956	$	5,956	$	—	$	—
Ownership interests	$	860	$	860	$	—	$	—