Note 7 - Components of Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Balance	$ 189,069	$ 191,559	$ 200,607	$ 183,726
Unrealized holding gain (loss) on available for sale securities, net of tax			(5,074)
Reclassification adjustment, net of tax			(4)
Balance	191,235	195,781	191,235	195,781
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance	854	3,930	13,167	76
Unrealized holding gain (loss) on available for sale securities, net of tax	7,235	5,637		9,507
Reclassification adjustment, net of tax		(49)		(65)
Balance	8,089	9,518	8,089	9,518
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(10,147)	(8,582)	(10,147)	(8,582)
Balance	(10,147)	(8,582)	(10,147)	(8,582)
AOCI Attributable to Parent [Member]
Balance	(9,293)	(4,652)	3,020	(8,506)
Unrealized holding gain (loss) on available for sale securities, net of tax	7,235	5,637		9,507
Reclassification adjustment, net of tax		(49)		(65)
Balance	$ (2,058)	$ 936	$ (2,058)	$ 936