Note E - Related Party Transactions (Details Textual) - USD ($)	3 Months Ended
Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	10.00%
Assets under Management, Carrying Amount	$ 37,772,000	$ 26,811,000
Fund Management Fee, Percent	0.40%
Mtron Industries Inc [Member] \| Spinoff [Member]
Excess Separation Costs	$ 28,000
Mtron Industries Inc [Member]
Accounts Receivable, after Allowance for Credit Loss	246,000		$ 6,000
Mtron Industries Inc [Member] \| Monthly Payment [Member]
Related Party Transaction, Amounts of Transaction	4,000
Cash and Cash Equivalents [Member]
Assets under Management, Carrying Amount	20,943,000	10,295,000
Marketable Securities [Member]
Assets under Management, Carrying Amount	$ 16,829,000	$ 16,516,000

Represents the amount of excess separation costs.

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- Definition

Fund management fee percent.

+ References

No definition available.

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- Definition

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 310
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 954
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-Name Accounting Standards Codification
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-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481058/954-310-45-1

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- Definition

The carrying amount of assets an investment adviser manages on behalf of investors.

+ References

No definition available.

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- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
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- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

+ References

No definition available.

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