Note F - Long-term Debt - Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Total debt	$ 27,100	$ 27,100
Less: current portion of long-term debt	(8,730)	(4,926)
Long-term debt	18,370	22,174
Texas Capital Credit Facility [Member]
Total debt	17,100	17,100
Paycheck Protection Program CARES Act [Member]
Total debt	$ 10,000	$ 10,000