Discontinued Agribusiness Operations - Narrative (Details) $ in Thousands		3 Months Ended			9 Months Ended
	Jul. 31, 2015 USD ($) account permit	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross selling price	$ 105,300
Selling price	127,000
Working capital adjustment	$ 22,000
Period to determine final working capital adjustment	90 days
Debt	$ 80,900						$ 84,045
Selling and other related costs	5,900
Net proceeds	18,400
Escrow deposit	$ 10,200
Number of escrow accounts | account	2
Number of environmental permits | permit	2
Period for resolution of operational matters	6 months
Impairment loss on classification of assets as held-for-sale, net of tax		$ (1,348)	$ (16,900)		$ (18,251)
Indemnification Agreement
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow deposit	$ 6,000
Period for release of escrow	18 months
Indemnification claims guaranteed in excess of escrow	$ 8,000
Period of guarantee	5 years
Performance Guarantee
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow deposit	$ 4,200
Performance Guarantee, Waste Water
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow deposit	1,800
Performance Guarantee, Air Quality
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow deposit	$ 2,400