Other Operating Expenses - Narrative (Details) - Wildhorse Resource Development Corporation $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($)
Business Acquisition [Line Items]
Acquisition related costs	$ 23
Severance expense	$ 38

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

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