Note 10 - Commitments and Contingencies (Details Textual) - State of Hawai'i Department of Health Notice and Finding of Violation and Order [Member]	Dec. 31, 2018 USD ($)	Apr. 24, 2026 gal
Loss Contingency, Damages Awarded, Value \| $	$ 230,000
Subsequent Event [Member]
Wastewater Treatment Construction Approved, Volume Per Day (Gallon) \| gal		75,000

Amount of damages awarded to the plaintiff in the legal matter.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-9

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483076/450-20-50-4

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration