Investments - Short term invesmtments (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Notes to Financial Statements
U.S. treasury bills	$ 0	$ 1,996,815
Certificates of deposit	200,000	200,000
Total short-term investments	$ 200,000	$ 2,196,815

Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

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(4))
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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