Note 5 - Income Taxes - Income Tax Effects of Temporary Differences That Comprise Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Noncurrent deferred tax assets (liabilities):
Accounts receivable		$ 46
Other accrued expenses	50	339
Property, plant and equipment	(1)	(659)
Notes receivable fair value adjustment	413
Employee benefits	95	1,970
Contribution carryforward
AMT credit	698	1,192
Net operating loss	7,743	6,733
Gross non-current deferred tax assets	8,998	9,621
Less valuation allowance	(8,504)	(9,621)
Net noncurrent deferred tax assets	$ 494