Summary of Significant Accounting Policies - Derivatives (Details)	12 Months Ended
Dec. 31, 2018 bbl
Derivatives not designated as hedging instruments \| Commodity product \| Maximum
Derivative Financial Instruments
Aggregate units of products in a controlled trading program	250,000

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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