Commitments and Contingencies - Environmental Health and Safety (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Mar. 31, 2018	Jan. 31, 2018	Dec. 31, 2018	Nov. 05, 2018	Dec. 31, 2017
Site Contingency [Line Items]
Lump sum Payment to subsidiary				$ 34.0
Lump sum settlement payment, previously recognized as indemnification receivable				$ 14.0
Remaining settlement amount received, attributable to remediation costs			$ 16.0
Remaining settlement amount received, attributable to concessions made under Settlement Agreement			4.0
Accrued environmental liabilities			$ 143.3		$ 76.1
Expected expending period			30 years
Pipeline release liabilities			$ 58.7		33.7
El Dorado Refinery Prior Owner Case
Site Contingency [Line Items]
Accrued environmental liabilities			143.3
Other current liabilities
Site Contingency [Line Items]
Accrued environmental loss contingencies			3.8		$ 7.2
Other current liabilities | El Dorado Refinery Prior Owner Case
Site Contingency [Line Items]
Accrued environmental loss contingencies			$ 3.8
Alon USA Energy, Inc. | Minimum
Site Contingency [Line Items]
Accrual for environmental loss contingencies, discount rate (as a percentage)			2.31%
Alon USA Energy, Inc. | Maximum
Site Contingency [Line Items]
Accrual for environmental loss contingencies, discount rate (as a percentage)			2.84%
Alon USA Energy, Inc. | Big Spring Refinery
Site Contingency [Line Items]
Site contingency, negotiation period (in years)			10 years
Product liability contingency, loss exposure not accrued, best estimate			$ 0.5
Estimated time frame to resolve contingency (in years)			10 years
Payment for penalties		$ 0.4
Alon USA Energy, Inc. | Paramount Refinery
Site Contingency [Line Items]
Payment for penalties	$ 0.3
Tyler Refinery
Site Contingency [Line Items]
Accrual for environmental loss contingencies, discount rate (as a percentage)			2.78%
Magnolia Station Spill | Magnolia Station Spill | Other current liabilities
Site Contingency [Line Items]
Pipeline release liabilities			$ 2.2