Note H - Fair Value of Financial Instruments - Reconciliation of Beginning and Ending Balances for Derivative and Warrant Liability Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Balance as of beginning of period	$ 306	$ 255
Adjustment to fair value	(222)	37
Balance as of end of period	$ 84	$ 292