Commitments and Contingencies - Additional Information (Details) (USD $)	12 Months Ended				0 Months Ended
	Dec. 31, 2013 T	Dec. 31, 2012	Dec. 31, 2013 Surety bonds Certain development projects	Dec. 31, 2012 Surety bonds Certain development projects	Nov. 06, 2013 AgReserves Sale
Commitments and Contingencies Disclosure [Abstract]
Threshold of ownership percentage in Company for private investigation of compliance	5.00%
Environmental liabilities	$ 1,071,000	$ 1,621,000
Purchase obligations, total	21,000,000
Purchase obligations, 2014	19,700,000
Purchase obligations, 2015	1,100,000
Purchase obligations, 2016	200,000
Supply commitment (in tons)	3,900,000
Gain (loss) on contract termination					21,000,000
Guarantor Obligations [Line Items]
Commitment obligations			14,100,000	10,300,000
Proposed land sale, reimburseable costs and expenses upon termination					$ 1,500,000.0