Note 7 - Dividends (Details Textual) - USD ($)			12 Months Ended
Apr. 12, 2018	Mar. 22, 2018	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Dividends Payable, Amount Per Share		$ 0.12			$ 0.10
Payments of Ordinary Dividends, Common Stock	$ 233,099		$ 233,099	$ 194,250
Dividends Payable, Date Declared		Mar. 22, 2018
Dividends Payable, Date of Record		Apr. 05, 2018

The per share amount of a dividend declared, but not paid, as of the financial reporting date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

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- Definition

Date the dividend to be paid was declared, in CCYY-MM-DD format.

+ References

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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

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- Definition

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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