Note 16 - Components of Accumulated Other Comprehensive Income (Loss) - Components of Accumulated Other Comprehensive Income (Loss) (Details) (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net pension gain (loss) arising during the period, taxes	$ 394	$ 249	$ (115)
Amortization of prior service cost included in net periodic pension cost, tax	23	24	38
Transfer from held to maturity to available for sale securities, tax		237
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	1,486	(595)	296
Reclassification adjustment for gain included in net income, taxes	(119)	(4)	(4)
Net pension gain (loss) arising during the period, taxes	0	0	0
Amortization of prior service cost included in net periodic pension cost, tax	0	0	0
Transfer from held to maturity to available for sale securities, tax		237
Reclassification adjustment for gain included in net income, taxes	(119)	(4)	(4)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	0	0	0
Reclassification adjustment for gain included in net income, taxes	0	0	0
Net pension gain (loss) arising during the period, taxes	(394)	(249)	115
Amortization of prior service cost included in net periodic pension cost, tax	(23)	(24)	(38)
Transfer from held to maturity to available for sale securities, tax		0
Reclassification adjustment for gain included in net income, taxes	0	0	0
AOCI Attributable to Parent [Member]
Unrealized holding gain (loss) on available for sale securities, tax	1,486	(595)	296
Reclassification adjustment for gain included in net income, taxes	(119)	(4)	(4)
Net pension gain (loss) arising during the period, taxes	(394)	(249)	115
Amortization of prior service cost included in net periodic pension cost, tax	(23)	(24)	(38)
Transfer from held to maturity to available for sale securities, tax		237
Reclassification adjustment for gain included in net income, taxes	$ (119)	$ (4)	$ (4)

Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss).

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss).

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