Note M - 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	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Balance as of beginning of period	$ 1,845	$ 7,709
Gain on extinguishment of debt		(2)
Adjustment to fair value	(1,749)	(5,862)
Balance as of end of period	$ 96	$ 1,845