Equity Securities at Fair Value (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Equity securities	$ 3,714,000		$ 3,714,000		$ 3,384,000
Change in fair value of equity securities	162,000	$ (147,000)	330,000	$ (68,000)
Proceeds from sale of equity securities	$ 0	$ 0	$ 0	$ 0

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Amount of increase (decrease) of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
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Amount of cash inflow from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as investing activity.

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