Note 14 - Retirement Plans - Summary of Net Periodic Pension Expense for ACS Retirement Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Interest cost	$ 604	$ 566
Expected return on plan assets	(678)	(792)
Amortization of loss	141	451
Net periodic pension expense	$ 67	$ 225