Note B - Marketable Securities - Net Gains and Losses on Marketable Securities (Details) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Net gains (losses) recognized during the year on marketable securities	$ 431,076	$ (333,138)
Less: Net gains recognized during the year on marketable securities sold during the period	(262,399)	(4,204)
Unrealized gains (losses) recognized during the reporting year on marketable securities still held at the reporting date	$ 168,677	$ (337,342)

Amount of unrealized and realized gain (loss) on investment in debt and equity securities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration