Commitments and Contingencies - Environmental Health and Safety (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Environmental liabilities, current	$ 8.2	$ 8.2
El Dorado refinery prior owner case
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Including Undiscounted Amounts	$ 144.5
Accrued Environmental Loss Contingencies, Expected Expending Period, Extension	30 years

Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

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