Note G - Stock-based Compensation (Details Textual) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
	Jan. 01, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures, Total (in shares)		22,180	64,277	60,922
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)		4,470
Share-based Payment Arrangement, Expense		$ 385			$ 1,057	$ 2,034	$ 3,664
Performance Shares [Member]
Share-based Payment Arrangement, Expense		$ 0			$ 0	$ 300	$ 0
2014 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)		6,530,725				6,530,725
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Reserved for Issuance, Incremental Percentage of Capital Stock Outstanding						4.00%
Increase in Common Stock Reserved for Issuance (in shares)	1,454,031
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures, Total (in shares)		22,180			0	147,379	81,720
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)		4,470			0	4,470	0