Note 7 - Income Taxes - Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Net operating losses	$ 65,852	$ 59,551
Fixed asset basis difference	4,551	4,559
Contributions carryover	32	4
Deferred compensation	1,073	1,352
Accrued liabilities	492	971
Total deferred tax assets	72,000	66,437
Valuation allowance for deferred tax assets	(72,000)	(66,437)
Net deferred tax asset