Note L - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Treasury Stock, Shares, Acquired			486,422
Treasury Stock Acquired, Average Cost Per Share			$ 12.07
Treasury Stock, Value, Acquired, Cost Method	$ 4,614	$ 1,490	$ 5,869	$ 2,802
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	261,588		261,588
Stock Issued During Period, Shares, Employee Stock Purchase Plans and Exercise of Share-based Awards			514,000