Note 1 - Significant Accounting Policies (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Sep. 06, 2018	Mar. 31, 2018
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.02	$ 0.02
Cash Held by Company in Escrow	$ 5,500,000
Financing Receivable, after Allowance for Credit Loss, Total	0		$ 1,883,000		$ 7,400,000
Financing Receivable, before Allowance for Credit Loss, Total	3,081,000		$ 3,271,000
Tangible Asset Impairment Charges, Total	0
A&R Note [Member]
Financing Receivable, before Allowance for Credit Loss, Total				$ 3,300,000
S&L Note [Member]
Financing Receivable, before Allowance for Credit Loss, Total				$ 4,400,000
Financing Receivable, Credit Loss, Expense (Reversal)	$ 992,000	$ 701,000