Note 15 - Fair Value Measurements and Fair Values of Financial Instruments - SBA Servicing Assets Sensitivity Analysis (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value of SBA Servicing Asset	$ 4,626	$ 4,447	$ 4,785	$ 5,243
Composition of SBA loans serviced for others	100.00%	100.00%
Weighted Average Remaining Term (in years) (Year)	20 years	20 years 8 months 12 days
Prepayment Speed	13.22%	13.53%
Effect on fair value of a 10% increase	$ (170)	$ (175)
Effect on fair value of a 20% increase	$ (329)	$ (338)
Weighted Average Discount Rate	10.00%	10.75%
Effect on fair value of a 10% increase	$ (152)	$ (154)
Effect on fair value of a 20% increase	$ (295)	$ (298)
Fixed Rate SBA Loans [Member]
Composition of SBA loans serviced for others	2.00%	2.00%
Adjustable Rate SBA Loans [Member]
Composition of SBA loans serviced for others	98.00%	98.00%

Small Business Administration loans presented as a percentage of an entity's total SBA loans.

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- Definition

Weighted average life of securitized assets regardless of when the transfer occurred, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(2)
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- Definition

Discount rate which is used to value residual cash flows generated by financial assets of a securitization, asset-backed financing arrangement, or similar transfer regardless of when the transfer occurred.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Estimated rate of prepayment of principal on financial assets regardless of when the transfer occurred.

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The hypothetical financial impact of a 10 percent adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

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The hypothetical financial impact of a 10 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

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The hypothetical financial impact of a 20 percent adverse change of the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

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The hypothetical financial impact of a 20 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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