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, 2017		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Outstanding (in shares)	507,500		507,500	822,500
Outstanding (in dollars per share)	$ 11.66		$ 11.66	$ 11.82
Outstanding (Year)	2 years 109 days		3 years 109 days	4 years 109 days	3 years 146 days
Outstanding	$ 3,394		$ 3,934	$ 3,934	$ 7,181
Granted (in shares)	0		0	0
Granted (in dollars per share)
Forfeited, Expired or canceled (in shares)				(315,000)
Forfeited, Expired or canceled (in dollars per share)				$ 12.09
Forfeited, Expired or canceled				$ 3,247
Exercised (in shares)	0
Exercised (in dollars per share)
Outstanding (in shares)	507,500	[1]	507,500	507,500	822,500
Outstanding (in dollars per share)	$ 11.66		$ 11.66	$ 11.66	$ 11.82
Options exercisable at December 31, 2017 (in shares)	507,500
Options exercisable at December 31, 2017 (in dollars per share)	$ 11.66
Options exercisable at December 31, 2017 (Year)	2 years 109 days
Options exercisable at December 31, 2017	$ 3,394
Weighted-average years of remaining contractual life of options outstanding at December 31, 2017 (Year)	2 years 109 days

[1] Exercise Prices vary from $9.88 to $12.51, and expiration dates vary from January 2020 to December 2021.