Exit Costs and Assets Held for Sale (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Restructuring Cost and Reserve [Line Items]
Assets held for sale	$ 151	$ 392	$ 9,816
Disposal Group, Held-for-sale, Not Discontinued Operations
Restructuring Cost and Reserve [Line Items]
Assets held for sale			9,800
Disposal Group, Held-for-sale, Not Discontinued Operations | Retail Store
Restructuring Cost and Reserve [Line Items]
Assets held for sale			4,200
Disposal Group, Held-for-sale, Not Discontinued Operations | Rail Group
Restructuring Cost and Reserve [Line Items]
Assets held for sale			4,100
Disposal Group, Held-for-sale, Not Discontinued Operations | Grain Group
Restructuring Cost and Reserve [Line Items]
Assets held for sale			1,300
Disposal Group, Held-for-sale, Not Discontinued Operations | Plant Nutrient Group
Restructuring Cost and Reserve [Line Items]
Assets held for sale			$ 200