Note 3 - Fair Value of Financial Instruments - Financial Instruments (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Reported Value Measurement [Member]
Total	$ 6,477,699	$ 6,200,568
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	3,280,289	1,860,736
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Certificates of Deposit, Short-term [Member]
Investment	2,697,000	3,370,000
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Certificates of Deposit, Long-term [Member]
Investment		725,000
Reported Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Mutual Fund [Member]
Investment	500,410	244,832
Estimate of Fair Value Measurement [Member]
Total	6,477,931	6,200,561
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	3,280,289	1,860,736
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Certificates of Deposit, Short-term [Member]
Investment	2,697,000	3,370,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Certificates of Deposit, Long-term [Member]
Investment		725,000
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Mutual Fund [Member]
Investment	$ 500,642	$ 244,825

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

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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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-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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