Segment Information - Information by Business Segment (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) Segment golf_course	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Segment Reporting Information [Line Items]
Number of reportable operating segments | Segment									5
Operating revenues	$ 21,104	$ 27,830	$ 37,846	$ 17,091	$ 15,676	$ 23,947	$ 68,164	$ 594,086	$ 103,871	$ 701,873	$ 131,256
Depreciation, depletion and amortization									9,486	8,422	9,131
Investment income, net									22,688	12,691	1,498
Interest expense									(11,429)	(8,608)	(2,040)
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									(1,163)	521,821	4,445
Capital expenditures									17,465	32,441	42,060
Assets	984,813				1,303,135				984,813	1,303,135
Revenues from RiverTown Sale										43,600
Revenues from AgReserves Sale										570,900
Interest Income, Other									694	990	234
Impairment losses									0	0	5,080
Pension charges									0	13,529	1,500
Residential real estate
Segment Reporting Information [Line Items]
Operating revenues									21,203	61,444	33,735
Depreciation, depletion and amortization									544	662	863
Interest expense									(1,174)	(1,316)	(1,999)
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									(821)	24,854	4,087
Capital expenditures									4,923	4,981	12,284
Assets	109,791				135,317				109,791	135,317
Impairment losses											200
Commercial real estate
Segment Reporting Information [Line Items]
Operating revenues									7,160	3,265	10,881
Interest expense									(1,489)	(696)	(41)
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									126	(163)	3,298
Capital expenditures									2,165	854	2,388
Assets	62,649				62,931				62,649	62,931
Resorts and leisure
Segment Reporting Information [Line Items]
Operating revenues									54,488	48,414	46,424
Depreciation, depletion and amortization									5,096	4,143	4,211
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									1,819	1,559	(1,561)
Capital expenditures									2,526	2,198	3,517
Assets	75,441				79,021				$ 75,441	79,021
Impairment losses											4,900
Number Of Golf Courses | golf_course									4
Leasing operations
Segment Reporting Information [Line Items]
Operating revenues									$ 8,978	6,977	4,306
Depreciation, depletion and amortization									3,118	2,685	2,126
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									676	1,165	324
Capital expenditures									5,849	22,600	19,969
Assets	82,120				74,800				82,120	74,800
Forestry
Segment Reporting Information [Line Items]
Operating revenues									12,042	581,442	35,450
Depreciation, depletion and amortization									581	729	1,775
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									10,259	517,087	13,406
Capital expenditures									1,366	1,537	3,678
Assets	20,244				20,521				20,244	20,521
Residential real estate and other
Segment Reporting Information [Line Items]
Investment income, net									571	994	113
Corporate
Segment Reporting Information [Line Items]
Investment income, net									22,117	11,697	1,385
Interest expense									(8,766)	(6,596)	0
(Loss) Income Before Equity In Loss From Unconsolidated Affiliates and Income Taxes									(13,222)	(22,681)	(15,109)
Interest Income, Other									8,200	6,100
Pension charges										13,500	1,500
Other
Segment Reporting Information [Line Items]
Operating revenues									0	331	460
Depreciation, depletion and amortization									147	203	156
Capital expenditures									636	271	$ 224
Assets	$ 634,568				$ 930,545				$ 634,568	$ 930,545