Real Estate Sales (Details)			1 Months Ended	3 Months Ended		9 Months Ended		18 Months Ended
	Apr. 02, 2014 USD ($) a	Mar. 05, 2014 USD ($)	Apr. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($) a	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2008 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Timberland Acreage Sales (in acres) | a							380,000
Other operating and corporate expenses				$ 9,847,000	$ 6,469,000	$ 24,696,000	$ 22,255,000
Investments held by special purpose entities		$ 203,500,000		208,720,000		208,720,000		$ 208,720,000	$ 209,857,000
Debt instrument, face amount			$ 180,000,000
Debt interest rate			4.75%
Proceeds from (repayments of) accounts receivable securitization			$ 165,000,000
Cost of monetization			$ 15,000,000
Retained interest promissory note receivable				20,000,000		20,000,000		20,000,000			$ 15,200,000
Discount and issuance costs						0	4,300,000
Administrative costs associated with special purpose entities				0	0	0	3,746,000
Senior Notes Held By Special Purpose Entity				177,418,000		177,418,000		177,418,000	177,341,000
Investment income, net				2,050,000	2,050,000	6,150,000	4,067,000
Interest expense				(2,189,000)	$ (2,185,000)	(6,566,000)	(4,397,000)
Impact Fees Received				0		100,000		200,000
Debt				69,726,000		69,726,000		69,726,000	63,804,000
Community Development District Debt				22,200,000		22,200,000		22,200,000	22,700,000
Rivers Edge Community Development District Assessments | Community Development District Debt
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt	$ 11,000,000
Community Development District Debt										$ 5,400,000
Carrying Value | Level 3
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Senior Notes Held By Special Purpose Entity				177,418,000		177,418,000		177,418,000	177,341,000
Northwest Florida Timber Finance, LLC | Notes Receivable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Issue price of senior secured notes			98.483%
Special Purpose Entities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discount and issuance costs			$ 4,300,000
Investments Contributed to Special Purpose Entity by the Company				7,000,000		7,000,000		7,000,000
Assets held by special purpose entities				211,400,000		211,400,000		211,400,000
Liabilities held by special purpose entities				178,100,000		178,100,000		178,100,000
U.S. treasury securities				8,500,000		8,500,000		8,500,000
Cash				200,000		200,000		200,000
Debt issuance cost						1,400,000
Unamortized discount (premium), net				2,600,000		2,600,000		2,600,000
Deposit liabilities, accrued interest				713,000		$ 713,000		713,000	$ 2,852,000
Held-To-Maturity Security, Term						15 years
U.S. Treasury securities maturing within one year				800,000		$ 800,000		800,000
U.S. Treasury securities maturing after one year through five years				3,600,000		3,600,000		3,600,000
U.S. Treasury securities maturing after five years through ten years				3,000,000		3,000,000		3,000,000
U.S. Treasury securities maturing after ten years				1,100,000		1,100,000		1,100,000
Special Purpose Entities | Notes Receivable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Debt interest rate	4.006%
Buyer Special Purpose Entity
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Time deposits				200,000,000		200,000,000		200,000,000
Accrued investment income receivable				$ 1,300,000		$ 1,300,000		$ 1,300,000
AgReserves Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proposed land sale, purchase price		562,000,000
Sale of real estate		511,100,000
Other operating and corporate expenses		1,200,000
Proceeds from sale of real estate		358,500,000
Disposal group consideration, notes receivable		$ 200,000,000
Timber Notes Receivable Maturity Period		15 years
RiverTown Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proposed land sale, purchase price	$ 24,000,000
Disposal group consideration, notes receivable	$ 19,600,000
Area of Land (in acres) | a	4,057
Disposal Group, Including Discontinued Operation, Expected Impact Fee Receivable, Period For Recognition	5 years
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal							$ 26,000,000
RiverTown Sale | Minimum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Expected Impact Fee Receivable	$ 20,000,000
RiverTown Sale | Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Expected Impact Fee Receivable	$ 26,000,000