Derivative Instruments and Hedging Activities - Narrative (Details) - bbl bbl in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Commodity contracts
Derivatives, Fair Value [Line Items]
Notional quantity (in bbl)	370	55

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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