Reporting Segments and Related Information - Reconciliation of Revenues, Segment Profits (Losses) and Net Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Segment revenues	$ 49,523	$ 45,619	$ 35,255
Equity in earnings (losses)	16,575	3,834	4,227
Investment income	1,239	1,344	462
Total revenues and other income	67,337	50,738	39,669
Segment Profits (Losses)
Segment profits	(1,431)	436	(7,518)
Other loss	(1,824)	(59)	(275)
Costs and expenses	(50,954)	(45,183)	(42,773)
Income (loss) before income taxes	14,559	5,555	(3,104)
Real estate - commercial/industrial
Revenues
Segment revenues	16,792	8,970	9,001
Equity in earnings (losses)	16,575	3,834	4,227
Segment Profits (Losses)
Costs and expenses	(12,961)	(6,246)	(6,529)
Income (loss) before income taxes	20,406	6,558	6,699
Real estate - resort/residential
Segment Profits (Losses)
Costs and expenses	(2,247)	(1,530)	(1,955)
Mineral resources
Revenues
Segment revenues	9,791	14,395	5,983
Segment Profits (Losses)
Costs and expenses	(5,818)	(6,223)	(2,964)
Farming
Revenues
Segment revenues	19,331	18,563	16,434
Segment Profits (Losses)
Costs and expenses	(15,251)	(16,028)	(16,201)
Ranch operations
Revenues
Segment revenues	3,609	3,691	3,837
Segment Profits (Losses)
Costs and expenses	(5,316)	(5,451)	(5,411)
Operating Segments
Revenues
Segment revenues	49,523	45,619	35,255
Segment Profits (Losses)
Segment profits	7,930	10,141	2,195
Operating Segments \| Real estate - commercial/industrial
Revenues
Segment revenues	16,792	8,970	9,001
Segment Profits (Losses)
Segment profits	3,831	2,724	2,472
Costs and expenses			(6,529)
Operating Segments \| Real estate - resort/residential
Segment Profits (Losses)
Segment profits	(2,247)	(1,530)	(1,955)
Operating Segments \| Mineral resources
Revenues
Segment revenues	9,791	14,395	5,983
Segment Profits (Losses)
Segment profits	3,973	8,172	3,019
Costs and expenses			(2,964)
Operating Segments \| Farming
Revenues
Segment revenues	19,331	18,563	16,434
Segment Profits (Losses)
Segment profits	4,080	2,535	233
Costs and expenses			(16,201)
Operating Segments \| Ranch operations
Revenues
Segment revenues	3,609	3,691	3,837
Segment Profits (Losses)
Segment profits	(1,707)	(1,760)	(1,574)
Corporate
Segment Profits (Losses)
Costs and expenses	$ (9,361)	$ (9,705)	$ (9,713)

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