Note 7 - Employee Retirement Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Apr. 21, 2016
Pension Plan Settlement Agreement, Amount Payable			$ 10,500
Pension Plan Settlement Agreement, Payment Schedule	with $1,500 due within ten days following the effective date of the Pension Settlement Agreement and the remainder paid in twelve annual installments of $750 beginning on October 31, 2015
Pension Plan Settlement Agreement, Stock Payable			88,117
Settled ERISA Liabilities			$ 46,000
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,100
Pension Cost (Reversal of Cost)	226	$ 217
Decrease (increase) in minimum pension liability	$ (206)	$ 200
Assumptions Used Calculating Benefit Obligation, Discount Rate	2.60%	3.80%
Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.60%	3.80%
Second Intercreditor Agreement
Line of Credit Facility, Maximum Borrowing Capacity	$ 3,000
Intercreditor Agreement
Line of Credit Facility, Maximum Borrowing Capacity	6,500
401K Deferred Savings Plan
Contribution by Employer	$ 482	$ 444