Note 2 - Fair Value Measurements - Fair Value of Assets and Liabilities on a Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Money market funds	$ 100,667	$ 100,166
Derivative Liability	5,572	13,833
Fair Value, Inputs, Level 1 [Member]
Money market funds	100,667	100,166
Derivative Liability	0	0
Fair Value, Inputs, Level 2 [Member]
Money market funds	0	0
Derivative Liability	0	0
Fair Value, Inputs, Level 3 [Member]
Money market funds	0	0
Derivative Liability	$ 5,572	$ 13,833