Note 6 - Components of Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Balances	$ 128,444	$ 136,244	$ 122,687	$ 191,751
Balances	116,113	112,187	116,113	112,187
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balances	(71,898)	(55,865)	(81,421)	2,854
Unrealized holding gain (loss) on available for sale securities, net of tax	(15,421)	(29,424)	(8,530)	(88,143)
Balances	(87,319)	(85,289)	(87,319)	(85,289)
Unrealized holding loss on available for sale securities, net of tax	(15,421)	(29,424)	(8,530)	(88,143)
Reclassification adjustment, net of tax			2,632
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balances	(2,345)	(6,912)	(2,345)	(6,912)
Unrealized holding gain (loss) on available for sale securities, net of tax	0		0
Balances	(2,345)	(6,912)	(2,345)	(6,912)
Unrealized holding loss on available for sale securities, net of tax	0		0
Reclassification adjustment, net of tax			0
AOCI Attributable to Parent [Member]
Balances	(74,243)	(62,777)	(83,766)	(4,058)
Unrealized holding gain (loss) on available for sale securities, net of tax	(15,421)	(29,424)	(8,530)	(88,143)
Balances	(89,664)	(92,201)	(89,664)	(92,201)
Unrealized holding loss on available for sale securities, net of tax	$ (15,421)	$ (29,424)	(8,530)	$ (88,143)
Reclassification adjustment, net of tax			$ 2,632