| **(Tables)**                     | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|----------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Segment Reporting [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| Information by Business Segment  | The accounting policies of the segments are the same as those described herein and in the Company’s Form 10-K. Total revenues represent sales to unaffiliated customers, as reported in the Company’s Consolidated Statements of Income. All intercompany transactions have been eliminated. Information by business segment is as follows: 2014 2013 2012OPERATING REVENUES:     Residential real estate (a)$61,384 $33,698 $22,115Commercial real estate3,265 10,881 10,400Resorts, leisure and leasing operations 55,451 50,767 44,407Forestry (b)581,442 35,450 38,977Other331 460 23,497Consolidated operating revenues$701,873 $131,256 $139,396      DEPRECIATION, DEPLETION AND AMORTIZATION:     Residential real estate$574 $776 $1,802Resorts, leisure and leasing operations6,916 6,424 5,714Forestry729 1,775 2,105Other reportable segments203 156 489Consolidated depreciation, depletion and amortization$8,422 $9,131 $10,110      INVESTMENT INCOME, NET     Residential real estate and other$994 $113 $68Corporate (c)11,697 1,385 639Consolidated investment income, net$12,691 $1,498 $707      INTEREST EXPENSE     Residential real estate$(1,316) $(1,999) $(2,802)Commercial and other (696) (41) (18)Corporate (d)(6,596) — —Consolidated interest expense$(8,608) $(2,040) $(2,820)      INCOME (LOSS) BEFORE EQUITY IN (INCOME) LOSS FROM UNCONSOLDIATED AFFILIATES AND INCOME TAXES:     Residential real estate (a)(e)$25,440 $4,558 $(6,772)Commercial real estate(163) 3,298 (271)Resorts, leisure and leasing operations (f)1,886 (1,928) (1,414)Forestry (b)517,087 13,406 13,475Corporate (c)(d)(g)(22,429) (14,889) 1,405Consolidated income (loss) before equity in (loss) income from unconsolidated affiliates and income taxes$521,821 $4,445 $6,423         2014 2013 2012CAPITAL EXPENDITURES:     Residential real estate$4,981 $12,284 $7,679Commercial real estate854 2,388 3,829Resorts, leisure and leasing operations24,798 23,486 9,023Forestry1,537 3,678 2,701Other271 224 163Total capital expenditures$32,441 $42,060 $23,395       December 31, 2014 December 31, 2013TOTAL ASSETS:   Residential real estate$129,663 $141,097Commercial real estate62,931 62,924Resorts, leisure and leasing operations158,226 142,940Forestry20,521 60,889Other931,794 261,622Total assets$1,303,135 $669,472(a)Includes revenues of $43.6 million from the RiverTown Sale in 2014. (b)Includes revenues of $570.9 million from the AgReserves Sale in 2014.(c)Includes interest income of $6.1 million from investments in special purpose entities in 2014. (d)Includes interest expense of $6.6 million from Senior Note issued by an special purpose entity in 2014.(e)Includes impairment losses of $0.2 million in 2013.(f)Includes impairment losses of $4.9 million and $2.6 million in 2013 and 2012, respectively.(g)Includes pension charges of $13.5 million, $1.5 million and $3.0 million in 2014, 2013 and 2012, respectively. |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8721-108599Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8813-108599Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8906-108599Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8736-108599
+ Details**Name:**us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock**Namespace Prefix:**us-gaap_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_SegmentReportingAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |