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Note 5 - Fair Value Measurements - Fair Value Quantitative Information (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Estimated Fair Value	$ 9,126	$ 10,524
Fair Value, Inputs, Level 3 [Member]
Estimated Fair Value	9,126	10,524
Appraisal Valuation [Member] | Fair Value, Inputs, Level 3 [Member] | Impaired Loan [Member]
Estimated Fair Value	8,899	10,306
Appraisal Valuation [Member] | Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member]
Estimated Fair Value	$ 227	$ 218
Appraisal Valuation [Member] | Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member] | Minimum [Member]
Unobservable Inputs, Rate	6.00%	6.00%
Appraisal Valuation [Member] | Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member] | Maximum [Member]
Unobservable Inputs, Rate	8.00%	8.00%
Appraisal Valuation [Member] | Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member] | Weighted Average [Member]
Unobservable Inputs, Rate	(7.00%)	(7.00%)

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- Definition

Percentage of estimation of value used as an input to measure fair value.

+ References

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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