INVESTMENTS (Details)			3 Months Ended		12 Months Ended
	Dec. 31, 2018 USD ($) a lot	Nov. 27, 2013 USD ($) partnership	Dec. 31, 2018 USD ($) a lot	Dec. 31, 2017 USD ($)	Sep. 30, 2017 a	Sep. 30, 2016	Sep. 30, 2018 USD ($)
Investment in Land [Line Items]
Investments	$ 1,177,000		$ 1,177,000				$ 1,608,000
Equity in loss of affiliates			$ (79,000)	$ (153,000)
Percent of Increment II distributions			50.00%
Contingent payments, unrecorded	8,000,000		$ 8,000,000
50% of Increment II distributions received	$ 3,500,000
Kaupulehu Developments
Investment in Land [Line Items]
Revenues - sale of interest in leasehold land			165,000	0
Fees - included in general and administrative expenses			(20,000)	0
Sale of interest in leasehold land, net of fees			$ 145,000	0
Kaupulehu Developments | Minimum
Investment in Land [Line Items]
Third party fees, percentage			10.40%
Kaupulehu Developments | Maximum
Investment in Land [Line Items]
Third party fees, percentage			11.60%
KD Kaupulehu LLLP Increment I | Kaupulehu Developments
Investment in Land [Line Items]
Number of lots remaining to be sold | lot	19		19
Aggregate gross proceeds from sale of increment I single family lots for calculating payments entitled to be received			$ 216,400,000
Number of lots sold | lot			1
Number of lots developed | lot			80
KD Kaupulehu LLLP Increment I | Kaupulehu Developments | Aggregate gross proceeds greater than $100,000,000 up to $300,000,000
Investment in Land [Line Items]
Payments entitled to be received as percentage of gross proceeds from sale of single family lots			10.00%
KD Kaupulehu LLLP Increment I | Kaupulehu Developments | Aggregate gross proceeds in excess of $300,000
Investment in Land [Line Items]
Payments entitled to be received as percentage of gross proceeds from sale of single family lots			14.00%
KD Kaupulehu LLLP Increment I | Kaupulehu Developments | Minimum | Aggregate gross proceeds greater than $100,000,000 up to $300,000,000
Investment in Land [Line Items]
Aggregate gross proceeds from sale of increment I single family lots for calculating payments entitled to be received			$ 100,000,000
KD Kaupulehu LLLP Increment I | Kaupulehu Developments | Minimum | Aggregate gross proceeds in excess of $300,000
Investment in Land [Line Items]
Aggregate gross proceeds from sale of increment I single family lots for calculating payments entitled to be received			300,000,000
KD Kaupulehu LLLP Increment I | Kaupulehu Developments | Maximum | Aggregate gross proceeds greater than $100,000,000 up to $300,000,000
Investment in Land [Line Items]
Aggregate gross proceeds from sale of increment I single family lots for calculating payments entitled to be received			$ 300,000,000
KD Kaupulehu LLLP Increment II | Kaupulehu Developments
Investment in Land [Line Items]
Number of lots sold					1	1
Number of lots developed					2
Percent of Increment II distributions			50.00%
Contingent payments, unrecorded	$ 8,000,000		$ 8,000,000
50% of Increment II distributions received	3,500,000
KD Kaupulehu LLLP Increment II | Kaupulehu Developments | Minimum
Investment in Land [Line Items]
Payments entitled to be received as percentage of gross proceeds from sale of single family lots			8.00%
Payments entitled to be received as percentage of gross proceeds from sale of units on a lot			2.60%
Increment II lot size | a					2
KD Kaupulehu LLLP Increment II | Kaupulehu Developments | Maximum
Investment in Land [Line Items]
Payments entitled to be received as percentage of gross proceeds from sale of single family lots			10.00%
Payments entitled to be received as percentage of gross proceeds from sale of units on a lot			3.25%
Increment II lot size | a					3
KKM Makai LLP | Barnwell Hawaiian Properties, Inc.
Investment in Land [Line Items]
Preferred return to be received as a percentage from KKM		100.00%
KKM Makai LLP | Barnwell Hawaiian Properties, Inc. | Maximum
Investment in Land [Line Items]
Preferred return, amount from KKM		$ 1,000,000
Investment in land development partnerships
Investment in Land [Line Items]
Investments	$ 1,127,000		$ 1,127,000				1,558,000
Number of limited liability limited partnerships formed | partnership		2
Ownership percentage		19.60%
Number of lots remaining to be sold | lot	19		19
Cash distribution from equity method investment			$ 314,000	0
Minority interests portion of distribution from equity investee			38,000
Cumulative cash distributions from Kukio Resort Land Development Partnerships, made to date			45,000,000
Equity in loss of affiliates			(79,000)	(153,000)
Basis difference between the underlying equity in net assets of the investee and the carrying value of the entity's investment	$ 313,000		313,000
Basis difference adjustment			1,000	3,000
Summarized financial information
Revenue			1,948,000	1,560,000
Gross profit			646,000	686,000
Net earnings			$ (158,000)	$ (503,000)
Investment in land development partnerships | Minimum
Investment in Land [Line Items]
Cumulative cash distributions from Kukio Resort Land Development Partnerships, threshold (in excess of)		$ 45,000,000
Investment in land development partnerships | KD Kukio Resorts, LLLP, KD Maniniowali, LLLP, and KD Kaupulehu, LLLP
Investment in Land [Line Items]
Ownership interest acquired, aggregate cost		$ 5,140,000
Investment in land development partnerships | KD Kukio Resorts LLLP
Investment in Land [Line Items]
Ownership interest acquired (as a percent)		19.60%
Investment in land development partnerships | KD Maniniowali, LLLP
Investment in Land [Line Items]
Ownership interest acquired (as a percent)		19.60%
Investment in land development partnerships | KD Kaupulehu, LLLP
Investment in Land [Line Items]
Ownership interest acquired (as a percent)		19.60%
Investment in land development partnerships | KD Kaupulehu LLLP Increment II Phase 2A
Investment in Land [Line Items]
Number of single family lots, rights to	3		3
Investment in land development partnerships | KKM Makai LLP
Investment in Land [Line Items]
Ownership interest acquired (as a percent)		34.45%
Land in leasehold land interest - Lot 4C
Investment in Land [Line Items]
Investments	$ 50,000		$ 50,000				$ 50,000
Area of land (in acres) | a	1,000		1,000