Note 8 - Income Tax - Tax Effects of Temporary Differences (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal income taxes
Current	$ 443	$ 1,036	$ 1,201
Deferred	1,717	898	(9,332)
Total federal tax expense (benefit)	2,160	1,934	(8,131)
State income taxes
Current	574	503	284
Deferred	(341)	308	(9)
Total state tax expense	233	811	275
Total income tax expense (benefit)	$ 2,393	$ 2,745	$ (7,856)