Exit Costs and Assets Held for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Assets held for sale	$ 364	$ 392	$ 57,775
Disposal Group, Held-for-sale, Not Discontinued Operations
Restructuring Cost and Reserve [Line Items]
Assets held for sale		57,800
Disposal Group, Held-for-sale, Not Discontinued Operations | Retail Store
Restructuring Cost and Reserve [Line Items]
Property, plan and equipment held-for-sale		4,200
Disposal Group, Held-for-sale, Not Discontinued Operations | Plant Nutrient Group
Restructuring Cost and Reserve [Line Items]
Property, plan and equipment held-for-sale		1,600
Disposal Group, Held-for-sale, Not Discontinued Operations | TENNESSEE | Grain Group
Restructuring Cost and Reserve [Line Items]
Property, plan and equipment held-for-sale		19,400
Inventory, held-for-sale		13,800
Commodity derivative, held-for-sale		$ 18,800