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	Jul. 01, 2023 USD ($)	Jun. 29, 2022 $ / shares shares	Apr. 01, 2019 USD ($)
Income Statement [Abstract]
Operating Lease, Lease Income	$ 8,461,000	$ 8,513,000
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
Impairment of Deferred Development Costs	$ 0	$ 0
Government Assistance, Operating Income, Increase (Decrease), Statement of Income or Comprehensive Income [Extensible Enumeration]	Operating Lease, Lease Income
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, Award Amount			$ 510,000
Grants Receivable	$ 75,000				$ 1,100,000
Government Assistance, Operating Income, Increase (Decrease)	$ 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
Joint Venture Agreement With BRE2 LLC [Member]
Area of Land (Acre) | a	30
Revision of Prior Period, Error Correction, Adjustment [Member]
Income Statement [Abstract]
Operating Lease, Lease Income	$ 0
Land and Development Sales [Member]
Revenue from Contract with Customer, Including Assessed Tax	0	$ 11,600,000
Land and Development Sales [Member] | Revision of Prior Period, Error Correction, Adjustment [Member]
Revenue from Contract with Customer, Including Assessed Tax	$ (1,626,000)
HAWAII
Area of Land (Acre) | a	22,300