Note 12 - Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020		Mar. 31, 2019
Balance	$ 406,297		$ 366,500
Balance	409,702		377,994
Net current period other comprehensive income (loss)	5,775		2,629
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance	1,085		(5,330)
Net current period other comprehensive income gain (loss)	6,038
Balance	7,123	[1]	(2,536)
Net current period other comprehensive income (loss)			2,794
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	(39)		408
Net current period other comprehensive income gain (loss)	(263)
Balance	(302)	[1]	234
Net current period other comprehensive income (loss)			(174)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(369)		(220)
Net current period other comprehensive income gain (loss)	0
Balance	(369)	[1]	(211)
Net current period other comprehensive income (loss)			9
AOCI Attributable to Parent [Member]
Balance	677		(5,142)
Net current period other comprehensive income gain (loss)	5,775
Balance	6,452	[1]	(2,513)
Net current period other comprehensive income (loss)	$ 5,775		$ 2,629

[1] December 31, 2017 AOCI component balances reflect a correction of incorrectly reported year-end balances in the Footnote titled "Other Comprehensive Income (Loss)" of the 2017 Form 10-K, which were presented as $(2,278), $234, and $(392) for securities AFS, cash flow hedges, and minimum pension liability, respectively.