Note 3 - Periodic Pension Expense - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Service cost - benefits earned during the period	$ 29	$ 27	$ 58	$ 54
Interest cost on projected benefit obligation	271	243	542	485
Expected return on plan assets	(384)	(430)	(721)	(859)
Recognized actuarial loss	324	283	649	566
Settlement loss	336		336
Net periodic pension cost	$ 576	$ 123	$ 864	$ 246