Note F - Long-term Debt - Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Total debt	$ 13,100	$ 27,100
Less: current portion of long-term debt	0	(4,926)
Long-term debt	13,100	22,174
Texas Capital Credit Facility [Member]
Total debt	13,100	17,100
Paycheck Protection Program CARES Act [Member]
Total debt	$ 0	$ 10,000