Note 9 - Stockholders' Equity - Reconciliation of Activity in Stockholders' Equity Accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Balance	$ 13,644
Net income (loss)	1,366	$ (3,367)
Balance	15,031
Settlement of employee benefit obligations directly related to the disposal transaction		2,422
Common Stock [Member]
Balance	294	298
Net income (loss)
Stock-based compensation expense
Balance	294	298
Settlement of employee benefit obligations directly related to the disposal transaction
Stock repurchase
Dividends
Additional Paid-in Capital [Member]
Balance	17,285	17,104
Net income (loss)
Stock-based compensation expense	21	391
Balance	17,306	17,253
Settlement of employee benefit obligations directly related to the disposal transaction
Stock repurchase		(103)
Dividends		(139)
Retained Earnings [Member]
Balance	(3,935)	(2,745)
Net income (loss)	1,366	(3,367)
Stock-based compensation expense
Balance	(2,569)	(6,112)
Settlement of employee benefit obligations directly related to the disposal transaction
Stock repurchase
Dividends
AOCI Attributable to Parent [Member]
Balance		(2,422)
Net income (loss)
Stock-based compensation expense
Balance
Settlement of employee benefit obligations directly related to the disposal transaction		2,422
Stock repurchase
Dividends