Note 3 - Periodic Pension Expense - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Service cost - benefits earned during the period	$ 29	$ 27
Interest cost on projected benefit obligation	271	242
Expected return on plan assets	(337)	(429)
Recognized actuarial loss	325	283
Net periodic pension cost	$ 288	$ 123