Note 15 - Accumulated Other Comprehensive Income - Components of Accumulated Other Comprehensive Income, Net of Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Balance	$ 427,775	[1]	$ 426,730		$ 428,819
Other comprehensive (loss) income, net	(14,173)		377		(417)
Balance	421,985		427,775	[1]	426,730
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balance	15		1,106		866
Other comprehensive (loss) income before reclassifications	(15,636)		(1,091)		544
Reclassified from AOCI	0		0		(304)
Other comprehensive (loss) income, net	(15,636)		(1,091)		240
Balance	(15,621)		15		1,106
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(1,561)		(3,029)		(2,372)
Other comprehensive (loss) income before reclassifications	1,357		1,160		(961)
Reclassified from AOCI	106		308		304
Other comprehensive (loss) income, net	1,463		1,468		(657)
Balance	(98)		(1,561)		(3,029)
AOCI Attributable to Parent [Member]
Balance	(1,546)		(1,923)		(1,506)
Other comprehensive (loss) income before reclassifications	(14,279)		69		(417)
Reclassified from AOCI	106		308		0
Other comprehensive (loss) income, net	(14,173)		377		(417)
Balance	$ (15,719)		$ (1,546)		$ (1,923)

[1] Derived from audited financial statements