Note 1 - Organization and Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Balance	$ 85,106	$ 81,428
Balance	88,380	83,675
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance	582	51
Other comprehensive income before reclassifications	(814)	757
Amounts reclassified from accumulated other comprehensive income, net of tax	(209)	(249)
Balance	(441)	559
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance	(1,103)	(975)
Other comprehensive income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income, net of tax	0	0
Balance	(1,103)	(975)
AOCI Attributable to Parent [Member]
Balance	(521)	(924)
Other comprehensive income before reclassifications	(814)	757
Amounts reclassified from accumulated other comprehensive income, net of tax	(209)	(249)
Balance	$ (1,544)	$ (416)