Income Taxes - Narrative (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	[1]	Jun. 30, 2019		Jun. 30, 2018	[1]	Feb. 01, 2019
Business Acquisition [Line Items]
Effective income tax rate	0.00%
Income tax benefit	$ 0		$ 9,000,000		$ 314,000,000	[1]	$ 9,000,000
Wildhorse Resource Development Corporation
Business Acquisition [Line Items]
Deferred tax liabilities		$ 314,000,000							$ 314,000,000
Income tax benefit	0	314,000,000			314,000,000
Deferred tax liability, plant, property and equipment and prepaid compensation		401,000,000
Deferred tax assets, operating loss carryforward, limitations	$ 61,000,000				$ 61,000,000
Wildhorse Resource Development Corporation | Federal
Business Acquisition [Line Items]
Deferred tax asset, operating loss carryforward		$ 87,000,000

[1] Financial information for 2018 has been recast to reflect the retrospective application of the successful efforts method of accounting. See Note 1.