Note 7 - Stock-based Awards - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands				12 Months Ended
		Jul. 24, 2018	May 03, 2018	Dec. 31, 2018	Dec. 31, 2017
Outstanding (in shares)				279,000
Outstanding, weighted average exercise price (in dollars per share)				$ 15.40
Outstanding, aggregate intrinsic value	[1]			$ 493	$ 1,436
Granted (in shares)		2,500	117	119,000
Granted, weighted average exercise price (in dollars per share)				$ 21.01
Exercised (in shares)
Exercised, weighted average exercise price (in dollars per share)
Forfeited (in shares)
Forfeited, weighted average exercise price (in dollars per share)
Outstanding (in shares)				398,000	279,000
Outstanding, weighted average exercise price (in dollars per share)				$ 17.09	$ 15.40
Exercisable (in shares)				143,000	56,000
Exercisable, weighted average exercise price (in dollars per share)
Exercisable, aggregate intrinsic value	[1]			$ 313

[1] The aggregate intrinsic value on this table was calculated based on the amount, if any, by which the closing market price of the Company’s stock on December 31 of the applicable year exceeded the exercise price of any of the underlying options, multiplied by the number of shares subject to each such option. The closing stock price as of December 31, 2018 and 2017 was $15.87 and $20.56, respectively.