Note K - Comprehensive Income (Loss) - Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Net loss	$ (6,235)	$ 5,118	$ (3,803)	$ (13,527)	$ (1,117)	$ (17,330)
Other comprehensive income (loss):
Adjustment to pension liability	812		732		1,624	1,465
Tax expense	(203)		(183)		(406)	(366)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax, Total	609		549		1,218	1,099
Foreign currency translation adjustment	496		377		(62)	349
Adoption of ASU 2018-02						(11,355)
Total other comprehensive income, net of tax	1,105	$ 51	926		1,156	(9,907)
Comprehensive loss	$ (5,130)		$ (2,877)		$ 39	$ (27,237)