Note B - Marketable Securities (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Proceeds from Sale and Maturity of Marketable Securities, Total	$ 6,371,128	$ 15,964,917
Debt and Equity Securities, Realized Gain (Loss), Total	$ 415,595	$ 262,399

The cash inflow associated with the aggregate amount received by the entity through sale or maturity of marketable securities (held-to-maturity or available-for-sale) during the period.

No definition available.

Name:	us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration