Reporting Segments and Related Information - Information Pertaining to Assets of Segments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Information pretaining to assets of the business segments
Identifiable Assets	$ 518,199	$ 439,701	$ 431,919
Depreciation and amortization	4,551	4,549	5,090
Capital Expenditures	21,709	26,380	28,048
Operating Segments | Real estate - commercial/industrial
Information pretaining to assets of the business segments
Identifiable Assets	63,065	65,290	67,550
Depreciation and amortization	615	585	552
Capital Expenditures	4,638	5,196	7,023
Operating Segments | Real estate - resort/residential
Information pretaining to assets of the business segments
Identifiable Assets	258,697	243,963	228,064
Depreciation and amortization	63	77	71
Capital Expenditures	14,230	16,013	16,404
Operating Segments | Mineral resources
Information pretaining to assets of the business segments
Identifiable Assets	48,305	45,066	46,025
Depreciation and amortization	1,363	1,357	1,501
Capital Expenditures	356	2,161	1,199
Operating Segments | Farming
Information pretaining to assets of the business segments
Identifiable Assets	36,317	36,895	32,542
Depreciation and amortization	996	1,150	929
Capital Expenditures	2,129	2,006	2,583
Operating Segments | Ranch operations
Information pretaining to assets of the business segments
Identifiable Assets	3,625	3,893	4,313
Depreciation and amortization	601	607	377
Capital Expenditures	220	523	299
Corporate
Information pretaining to assets of the business segments
Identifiable Assets	108,190	44,594	53,425
Depreciation and amortization	913	773	1,660
Capital Expenditures	$ 136	$ 481	$ 540