Note 6 - Components of Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Balances	$ 131,043	$ 161,289	$ 122,687	$ 191,751
Balances	128,444	136,240	128,444	136,240
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balances	(69,692)	(30,972)	(81,421)	2,854
Unrealized holding gain (loss) on available for sale securities, net of tax	(4,848)	(24,893)	6,891	(58,719)
Reclassification adjustment, net of tax	2,642		2,632
Balances	(71,898)	(55,865)	(71,898)	(55,865)
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
Reclassification adjustment, net of tax	0		0
Balances	(2,345)	(6,912)	(2,345)	(6,912)
AOCI Attributable to Parent [Member]
Balances	(72,037)	(37,884)	(83,766)	(4,058)
Unrealized holding gain (loss) on available for sale securities, net of tax	(4,848)	(24,893)	6,891	(58,719)
Reclassification adjustment, net of tax	2,642		2,632
Balances	$ (74,243)	$ (62,777)	$ (74,243)	$ (62,777)