Note 14 - Retirement Plans - Summary of Net Periodic Pension Expense for ACS Retirement Plan (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Interest cost	$ 150	$ 141	$ 300	$ 282
Expected return on plan assets	(169)	(198)	(339)	(396)
Amortization of loss	141	148	282	296
Net periodic pension expense	$ 122	$ 91	$ 243	$ 182