Real Estate Sales (Details) (USD $)	1 Months Ended	12 Months Ended			0 Months Ended		3 Months Ended
	Apr. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 05, 2014 acre	Apr. 02, 2014 acre	Jun. 30, 2014	Mar. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other operating expenses		$ 13,459,000	$ 12,323,000	$ 15,321,000
Investments held by special purpose entities		209,857,000	0		203,500,000
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
Promissory Note, Expected Net Interest Payment And Principal Amount		20,000,000
Administrative costs associated with special purpose entities		3,746,000	0	0
Percent Ownership in Special Purpose Entity		0.00%
Senior Notes held by special purpose entity		177,341,000	0
Interest income from investments in special purpose entities		6,116,000	0	0
Interest expense and amortization of discount and issuance costs for Senior Notes issued by special purpose entity		6,584,000	0	0
Impact Fees Received		100,000
Long term debt		63,804,000	44,217,000
Total community development district debt		22,700,000	34,100,000
Community Development District Debt
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long term debt		6,516,000	11,512,000
Rivers Edge CDD Assessments | Community Development District Debt
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long term debt						11,000,000
Total community development district debt								5,400,000
Interest bearing homebuilder note for the RiverTown Sale, secured by the real estate sold — 5.25% interest rate, annual principal payment of $1.0 million due March 2015 and with all accrued interest and remaining principal and interest payment due June 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Notes receivable, effective interest rate		5.25%				5.25%
Debt Instrument, Expected Periodic Payment, Principal, Next Fiscal Year						1,000,000.0
Subsidiaries | 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]
Debt Financing Costs And Discounts	4,300,000
Investments Contributed to Special Purpose Entity by the Company		7,000,000
Assets Held by Special Purpose Entities		214,200,000
Liabilities Held by Special Purpose Entities		180,200,000
US Government Securities, at Carrying Value		9,400,000
Cash		400,000
Debt Issuance Cost		1,500,000
Senior Notes held by special purpose entity		177,300,000
Debt Instrument, Unamortized Discount (Premium), Net		2,700,000
Deposit Liabilities, Accrued Interest		2,852,000	0
Held-To-Maturity Security, Term		15 years
Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount		800,000
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value		3,700,000
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount		3,100,000
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount		1,800,000
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
Accrued Investment Income Receivable		2,900,000
AgReserves Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration					562,000,000
Sales of Real Estate, Gain (Loss) On Sale, Net of Associated Operating Costs					511,100,000
Other operating expenses		1,200,000
Proceeds from Sale of Real Estate					358,500,000
Disposal Group, Including Discontinued Operation, Consideration, Notes Receivable					200,000,000
Maturity of notes receivables	15 years				15 years
Proposed land sale, area of land (in acres)					380,000
RiverTown Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration						24,000,000
Disposal Group, Including Discontinued Operation, Consideration, Notes Receivable						19,600,000
Proposed land sale, area of land (in acres)						4,057
Proposed land sale, expected impact fee credit, 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]
Proposed land sale, expected impact fee credit						20,000,000
RiverTown Sale | Maximum
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proposed land sale, expected impact fee credit						$ 26,000,000