Summary of Significant Accounting Policies (Narrative) (Details)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) segment	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Number of operating segments | segment				1
Number of reportable segments | segment				1
Investment in equity securities	$ 128,000			$ 128,000		$ 133,000
Unrealized (loss) gain on fair value adjustment for equity securities		$ (3,000)		(5,000)	$ 55,000
Value of securities sold, but proceed not received					226,000
Gain (loss) on sale of investment in securities				0	13,000
Warrants, fair value	0			0		3,000
Unrealized gain (loss) on fair value adjustment for warrants	0			$ (3,000)	(28,000)
Equipment on operating leases, depreciation method				straight-line
Proceeds from sales of investment securities	0			$ 0	239,000
Securities with Readily Determinable Fair Values [Member]
Unrealized (loss) gain on fair value adjustment for equity securities	0	$ (3,000)		(5,000)	$ 55,000
Securities without Readily Determinable Fair Values [Member]
Investment in equity securities	125,000			125,000		$ 125,000
Unrealized (loss) gain on fair value adjustment for equity securities	0		$ 57,000	0
Investment securities without readily determinable market value, cumulative amount	$ 186,000			186,000
Minimum [Member]
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]
U.S. Treasury instruments maturity period				90 days
Cash deposits, insured amount	$ 250,000			$ 250,000
Operating leases, initial terms	120 months			120 months
Equipment and lessee period of review for impairment				90 days