Note D - Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating lease cost	$ 2,119	$ 2,378	$ 4,484	$ 4,593
Amortization of right-of-use assets	65	86	132	150
Interest on lease liabilities	13	19	27	38
Total Finance lease cost	78	105	159	188
Variable lease cost	722	840	1,642	1,377
Total lease cost	$ 2,919	$ 3,323	6,285	6,158
Operating cash flows from operating leases			10,661	8,631
Operating cash flows from finance leases			23	38
Financing cash flows from finance leases			$ 191	$ 227
Weighted Average Remaining Lease term, Operating leases (Year)	3 years 73 days	3 years 182 days	3 years 73 days	3 years 182 days
Weighted Average Remaining Lease term, Finance leases (Year)	3 years	3 years	3 years	3 years
Weighted Average Discount Rate, Operating leases	4.66%	4.74%	4.66%	4.74%
Weighted Average Discount Rate, Finance leases	6.34%	6.91%	6.34%	6.91%