Note 14 - Accumulated Other Comprehensive Income (Loss) - Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Balance	$ 651,089	$ 443,232	$ 440,701	$ 420,231	$ 409,702	$ 406,297	$ 440,701	$ 406,297
Balance	663,547	651,089	443,232	428,598	420,231	409,702	663,547	428,598
Net current period other comprehensive income (loss)	(4,421)	4,840	(11,791)	56	2,364	5,775	(11,372)	8,194
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance	2,295		9,310	9,466		1,085	9,310	1,085
Net current period other comprehensive income (loss)	(4,453)						(11,468)
Balance	(2,158)	2,295		9,437	9,466		(2,158)	9,437
Net current period other comprehensive income (loss)				(29)				8,352
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Balance	(58)		(122)	(281)		(39)	(122)	(39)
Net current period other comprehensive income (loss)	32						96
Balance	(26)	(58)		(196)	(281)		(26)	(196)
Net current period other comprehensive income (loss)				85				(157)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(447)		(447)	(369)		(369)	(447)	(369)
Net current period other comprehensive income (loss)	0						0
Balance	(447)	(447)		(369)	(369)		(447)	(369)
Net current period other comprehensive income (loss)				0				0
AOCI Attributable to Parent [Member]
Balance	1,790	(3,050)	8,741	8,816	6,452	677	8,741	677
Net current period other comprehensive income (loss)	(4,421)						(11,372)
Balance	(2,631)	1,790	(3,050)	8,872	8,816	6,452	$ (2,631)	8,872
Net current period other comprehensive income (loss)	$ (4,421)	$ 4,840	$ (11,791)	$ 56	$ 2,364	$ 5,775		$ 8,195