Summary of Significant Accounting Policies (Narrative) (Details)			3 Months Ended		9 Months Ended		12 Months Ended
	Jan. 22, 2022 USD ($)	Jan. 21, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($) contract $ / shares	Dec. 31, 2021 USD ($) $ / shares	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Summary of Significant Accounting Policies [Line Items]
Equipment on operating leases, depreciation method					straight-line
Taxes on income and franchise fees			$ 1,000	$ 1,000	$ 4,000	$ 3,000
Investment in equity securities			42,000		42,000		$ 308,000
Gain on sale of securities					0	78,000
Unrealized loss on fair value adjustment for equity securities			10,000	492,000	266,000	423,000
Options - short position			0	16,000	0	16,000	$ 1,000			$ 50,000
Options, short position, contract expiration date							Jan. 21, 2022
Unrealized gain on fair valuation of options				34,000	$ 0	34,000
Number of operating segments | segment					1
Number of reportable segments | segment					1
Unrealized gain (loss) on fair value adjustment for warrants			1,000	4,000	$ 3,000	(26,000)
Warrants, fair value			145,000	161,000	145,000	161,000	$ 142,000	$ 144,000	$ 157,000
Impairment on investments			0	0	0	0
Realized gain on sale of options	$ (1,000)	$ 1,000			1,000	0
Securities With Readily Determinable Fair Values [Member]
Summary of Significant Accounting Policies [Line Items]
Unrealized loss on fair value adjustment for equity securities			$ 10,000	492,000	266,000	$ 423,000
Short Position Options Sold - Tranche One [Member]
Summary of Significant Accounting Policies [Line Items]
Short position options, number of contracts sold | contract						125
Short position options contracts sold, premium per share | $ / shares						$ 3.00
Investment in short options, initial				38,000		$ 38,000
Options, short position, strike price per share | $ / shares							$ 15.00
Short Position Options Sold - Tranche Two [Member]
Summary of Significant Accounting Policies [Line Items]
Short position options, number of contracts sold | contract						75
Short position options contracts sold, premium per share | $ / shares						$ 1.64
Investment in short options, initial				$ 12,000		$ 12,000
Options, short position, strike price per share | $ / shares							$ 12.50
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Required assets value of financial institutions for cash deposits					$ 10,000,000,000
Operating leases, initial terms			36 months		36 months
Operating leases, period for non-accrual status					90 days
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Treasury instruments maturity period					90 days
Cash deposits, insured amount			$ 250,000		$ 250,000
Operating leases, initial terms			120 months		120 months
Operating leases, period of review for impairment					90 days