Note 15 - Board of Directors' Retirement Policy (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Arrangement with Individual, Recorded Liability	$ 74,238
Retirement Benefit Amortized Term	15 years
Director [Member]
Deferred Compensation Arrangement with Individual, Maximum Monthly Payment	$ 2,000
Deferred Compensation Arrangement, Vesting Percentage for Zero to Four Years of Service	20.00%
Deferred Compensation Arrangement, Vesting Percentage for Five Years of Service	40.00%
Deferred Compensation Arrangement, Vesting Percentage for Six Years of Service	60.00%
Deferred Compensation Arrangement, Vesting Percentage for Seven Years of Service	80.00%
Deferred Compensation Arrangement, Vesting Percentage for Eight Years of Service	100.00%
Liability, Defined Benefit Plan, Total	$ 268,000	$ 268,000

Represents the vesting percentage for eight years of service under deferred compensation arrangement.

No definition available.

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- Definition

Represents the vesting percentage for five years of service under deferred compensation arrangement.

+ References

No definition available.

+ Details

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- Definition

Represents the vesting percentage for seven years of service under deferred compensation arrangement.

+ References

No definition available.

+ Details

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- Definition

Represents the vesting percentage for six years of service under deferred compensation arrangement.

+ References

No definition available.

+ Details

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- Definition

Represents the vesting percentage for zero to four years of service under deferred compensation arrangement.

+ References

No definition available.

+ Details

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- Definition

Represents the maximum monthly payment under deferred compensation arrangement with individuals.

+ References

No definition available.

+ Details

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- Definition

Retirement benefit amortized term in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363

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- Definition

Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(15))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(15))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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