Note 6 - Components of Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Balances	$ 122,687	$ 191,751
Balances	131,043	161,289
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balances	(81,421)	2,854
Unrealized holding gain (loss) on available for sale securities, net of tax	11,738	(33,826)
Reclassification adjustment, net of tax of ($3)	(9)
Balances	(69,692)	(30,972)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balances	(2,345)	(6,912)
Unrealized holding gain (loss) on available for sale securities, net of tax	0
Reclassification adjustment, net of tax of ($3)	0
Balances	(2,345)	(6,912)
AOCI Attributable to Parent [Member]
Balances	(83,766)	(4,058)
Unrealized holding gain (loss) on available for sale securities, net of tax	11,738	(33,826)
Reclassification adjustment, net of tax of ($3)	(9)
Balances	$ (72,037)	$ (37,884)