Note 6 - Employee Retirement Benefit Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Apr. 21, 2015
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)	231	$ 262
Decrease (increase) in minimum pension liability	$ (30)	$ 258
Assumptions Used Calculating Benefit Obligation, Discount Rate	3.40%	3.70%
Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.40%	3.70%
401K Deferred Savings Plan
Contribution by Employer	$ 451	$ 182
Intercreditor Agreement
Line of Credit Facility, Maximum Borrowing Capacity	6,500
Second Intercreditor Agreement
Line of Credit Facility, Maximum Borrowing Capacity	$ 3,000