Note I - Income Taxes - Significant Portions of the Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred compensation and retirement plan	$ 16,541	$ 18,067
Accrued expenses not deductible until paid	237	2,331
Lease liability	6,346	4,217
Employee stock-based compensation	440	736
Accrued payroll not deductible until paid	108	196
Accounts receivable, net	53	156
Investment in foreign subsidiaries, outside basis difference	1,124	1,336
Goodwill	581	649
Interest Expense limitations	1,530
Other, net	440	156
Foreign net operating loss carryforwards	1,771	2,364
State net operating loss carryforwards	4,763	4,387
Foreign tax credit carryforwards	3,653	3,653
Federal net operating loss carryforwards		5,394
Total gross deferred tax assets	37,587	43,642
Less valuation allowances	(30,841)	(38,379)	$ (31,170)
Net deferred tax assets	6,746	5,263
Property, plant and equipment	(625)	(1,159)
Right-of-use asset	(5,583)	(3,785)
Prepaid Expenses	(318)	(279)
Other, net	(220)	(284)
Total gross deferred tax liabilities	(6,746)	(5,507)
Net deferred tax assets (liabilities)		$ (244)