Accrued Liabilities and Deferred Credits - Additional Information (Details) (USD $)	0 Months Ended	12 Months Ended
	Mar. 05, 2014	Dec. 31, 2006 acre	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred revenue			$ 15,309,000	$ 28,551,000
Deferred revenue, revenue recognized	1,100,000
Florida Department of Transportation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred revenue			12,500,000	23,500,000
Acres of land sold		3,900
AgReserves Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Acres of land sold	800
Deferred revenue, revenue recognized			$ 11,000,000