Note 14 - Retirement Plans - Summary of Net Periodic Pension Expense for ACS Retirement Plan (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Interest cost	$ 117	$ 150
Expected return on plan assets	(185)	(170)
Amortization of loss	35	141
Net periodic pension expense	$ (33)	$ 121