Note 13 - Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022		Sep. 30, 2021
Balance	$ 418,046	$ 427,534	$ 427,775	[1]	$ 426,730
Other comprehensive loss, net of tax	(7,365)	(88)	(17,479)		(730)
Balance	412,258	427,364	412,258		427,364
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Balance	(9,817)	474	15		1,106
Other comprehensive income (loss) before reclassifications	(7,392)	(164)	(17,224)		(796)
Reclassified from AOCI	0	0	0		0
Other comprehensive loss, net of tax	(7,392)	(164)	(17,224)		(796)
Balance	(17,209)	310	(17,209)		310
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(1,843)	(3,039)	(1,561)		(3,029)
Other comprehensive income (loss) before reclassifications	0	(1)	(335)		(163)
Reclassified from AOCI	27	77	80		229
Other comprehensive loss, net of tax	27	76	(255)		66
Balance	(1,816)	(2,963)	(1,816)		(2,963)
AOCI Attributable to Parent [Member]
Balance	(11,660)	(2,565)	(1,546)		(1,923)
Other comprehensive income (loss) before reclassifications	(7,392)	(165)	(17,559)		(959)
Reclassified from AOCI	27	77	80		229
Other comprehensive loss, net of tax	(7,365)	(88)	(17,479)		(730)
Balance	$ (19,025)	$ (2,653)	$ (19,025)		$ (2,653)

[1] Derived from audited financial statements