Commitments and Contingencies (Details Textual) $ in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2015	Dec. 31, 2017 USD ($) Joint_Venture	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2017 USD ($)
Operating Leased Assets [Line Items]
Lease income per diem arrangements recognized		$ 5.6	$ 4.9	$ 5.0
Management and service fees		5.9	5.7	7.0
Rental expense under agreements net		5.4	12.3	10.9
Future minimum lease payments, 2018		5.4
Future minimum lease payments, 2019		4.6
Future minimum lease payments, 2020		4.1
Future minimum lease payments, 2021		3.8
Future minimum lease payments, 2022		1.4
Future minimum lease payments, thereafter		$ 0.5
Number of ethanol joint ventures | Joint_Venture		2
Periods of lease income renewals		7 years 6 months
Operating lease income		$ 2.0	2.0	$ 2.0
Build-to-Suit Lease
Operating Leased Assets [Line Items]
Lease agreement initial term of contract	15 years
Build-to-Suit Lease | Other Long-term Liabilities
Operating Leased Assets [Line Items]
Built-to-suit financial obligation		24.3	14.0
Build-to-Suit Lease | Other Current Liabilities
Operating Leased Assets [Line Items]
Built-to-suit financial obligation		$ 1.4	$ 0.9
Plant Nutrient | Legal Claim 2015 [Member]
Operating Leased Assets [Line Items]
Loss contingency reserve					$ 2.2