Sale of Assets (Details) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) asset	Sep. 30, 2018 USD ($) security	Dec. 31, 2019 USD ($)	Dec. 31, 2017 USD ($) location	Jun. 30, 2018 USD ($)
Business Acquisition [Line Items]
Number of convertible preferred security investments sold | security			1
Proceeds from sale of convertible preferred security investments			$ 6.4
Other Income
Business Acquisition [Line Items]
Gain on sale of convertible preferred security investments			3.9
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Other Income
Business Acquisition [Line Items]
Gain sale of assets					$ 1.2
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Grain Elevators | Humboldt, Kenton and Dyer, Tennessee [Member]
Business Acquisition [Line Items]
Consideration received on sale of assets						$ 19.5
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Como Location
Business Acquisition [Line Items]
Working capital adjustments			$ 1.3
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Barge Vessels
Business Acquisition [Line Items]
Consideration received on sale of assets		$ 26.9
Number of assets sold | asset		50
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Barge Vessels | Other Income
Business Acquisition [Line Items]
Gain sale of assets		$ 2.4
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Retail Site
Business Acquisition [Line Items]
Consideration received on sale of assets					$ 14.7
Gain sale of assets		$ 4.9
Number of locations sold | location					3
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Retail Site | Other Income
Business Acquisition [Line Items]
Gain sale of assets					$ 8.6
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Farm Center | MICHIGAN
Business Acquisition [Line Items]
Consideration received on sale of assets	$ 4.6			$ 4.6
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Farm Center | MICHIGAN | Other Income
Business Acquisition [Line Items]
Gain sale of assets				2.9
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Farm Center | Florida
Business Acquisition [Line Items]
Consideration received on sale of assets					$ 17.4
Number of locations sold | location					4
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Farm Center | Florida | Other Income
Business Acquisition [Line Items]
Gain sale of assets					$ 4.7
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Grain and Agronomy Location
Business Acquisition [Line Items]
Consideration received on sale of assets	25.1			25.1
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Grain and Agronomy Location | Other Income
Business Acquisition [Line Items]
Gain sale of assets	5.7
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Grain and Agronomy Location | TENNESSEE
Business Acquisition [Line Items]
Consideration received on sale of assets	$ 0.6			0.6
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Grain and Agronomy Location | TENNESSEE | Other Income
Business Acquisition [Line Items]
Gain sale of assets				$ 0.6