Note 1 - Description of Business and Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2023 USD ($) a $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($)	Jul. 01, 2023 USD ($)	Jun. 29, 2022 $ / shares shares	Apr. 01, 2019 USD ($)
Capital Units, Authorized (in shares) | shares					48,000,000
Common Stock, Shares Authorized (in shares) | shares	43,000,000	43,000,000			43,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001			$ 0.0001
Preferred Stock, Shares Authorized (in shares) | shares					5,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares					$ 0.0001
Asset Impairment Charges | $	$ 0	$ 0	$ 0
Impairment of Deferred Development Costs | $	$ 0	$ 0
Weighted Average Number of Shares Outstanding, Basic (in shares) | shares	19,600,000	19,400,000
Weighted Average Number of Shares Outstanding, Diluted (in shares) | shares	19,700,000	19,400,000
Subsidized Stewardship and Conservation Efforts [Member]
Area of Land (Acre) | a	9,000
Government Assistance, Amount, Cumulative | $				$ 510,000,000,000
Grants Receivable | $	$ 75,000					$ 1,100,000
Government Assistance, Amount | $	$ 300,000	$ 400,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	40 years
HAWAII
Area of Land (Acre) | a	22,300