Reporting Segments and Related Information - Reconciliation of Revenues, Segment Profits (Losses) and Net Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Segment revenues	$ 35,657	$ 45,577	$ 51,147
Equity in earnings (losses)	4,227	7,098	6,324
Gain on sale of real estate	0	1,044	0
Investment income	462	457	528
Other income	153	158	381
Total revenues and other income	40,499	54,334	58,380
Segment profits (losses) and net income (loss)
Segment profits	(7,544)	(7,906)	(3,196)
Costs and expenses	(43,201)	(53,483)	(54,343)
(Loss) income before income taxes	(2,702)	851	4,037
Ranch operations
Segment profits (losses) and net income (loss)
Costs and expenses	(5,411)	(5,734)	(6,112)
Operating Segments
Revenues
Segment revenues	35,657	45,577	51,147
Segment profits (losses) and net income (loss)
Segment profits	2,597	4,644	9,612
Operating Segments | Real estate - commercial/industrial
Revenues
Segment revenues	9,403	9,438	8,272
Segment profits (losses) and net income (loss)
Segment profits	2,874	2,338	1,578
Costs and expenses	(6,529)	(7,100)	(6,694)
Operating Segments | Real estate - resort/residential
Segment profits (losses) and net income (loss)
Segment profits	(1,955)	(1,630)	(2,349)
Operating Segments | Mineral resources
Revenues
Segment revenues	5,983	14,153	15,116
Segment profits (losses) and net income (loss)
Segment profits	3,019	6,357	7,720
Costs and expenses	(2,964)	(7,796)	(7,396)
Operating Segments | Farming
Revenues
Segment revenues	16,434	18,648	23,836
Segment profits (losses) and net income (loss)
Segment profits	233	(25)	4,852
Costs and expenses	(16,201)	(18,673)	(18,984)
Operating Segments | Ranch operations
Revenues
Segment revenues	3,837	3,338	3,923
Segment profits (losses) and net income (loss)
Segment profits	(1,574)	(2,396)	(2,189)
Corporate
Segment profits (losses) and net income (loss)
Costs and expenses	$ (10,141)	$ (12,550)	$ (12,808)