Note 11 - Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Provision For Income Taxes [Abstract]
Current Federal income taxes									$ 3,137	$ 2,519	$ 2,276
Current state income taxes									62	51	0
Deferred Federal income taxes									(145)	0	368
Net provision	$ 743	$ 821	$ 702	$ 788	$ 571	$ 715	$ 583	$ 701	$ 3,054	$ 2,570	$ 2,644