Note 9 - Accumulated Other Comprehensive Income (Loss) - Significant Amounts Reclassified Out of Each Component of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Provision for income taxes	$ 518	$ 441
Total reclassifications for the period	2,436	2,174
Reclassification out of Accumulated Other Comprehensive Income [Member] | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member]
Unrealized gains and losses on available-for-sale securities	(9)	(26)
Provision for income taxes	2	6
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Total reclassifications for the period	$ (7)	$ (20)