Note 9 - Stock-based Compensation Plans and Warrants - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Outstanding (in shares)	507,500	507,500
Outstanding (in dollars per share)	$ 11.66	$ 11.66
Outstanding (Year)	1 year 109 days	2 years 109 days	3 years 109 days
Outstanding	$ 3,834	$ 3,934	$ 3,934
Granted (in shares)	0	0
Granted (in dollars per share)
Forfeited, Expired or canceled (in shares)	15,000
Forfeited, Expired or canceled (in dollars per share)	$ 11.75
Forfeited, Expired or canceled	$ 100
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	0
Exercised (in dollars per share)
Forfeited, Expired or canceled	$ 100
Options exercisable at December 31, 2018 (in shares)	492,500
Options exercisable at December 31, 2018 (in dollars per share)	$ 11.66
Options exercisable at December 31, 2018 (Year)	1 year 109 days
Options exercisable at December 31, 2018	$ 3,834
Weighted-average years of remaining contractual life of options outstanding at December 31, 2018 (Year)	1 year 109 days