Related Party Transactions - Joint Venture Narrative (Details) - Wolfcamp Drillco Operating L.P. $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) tranche
Related party transactions
Percent of estimated drilling, completion, and equipping costs of wells contributed by investor		60.00%
Number of investment tranches | tranche		2
Working interest in joint venture wells		50.00%
Internal rate of return on invested capital in each tranche		12.00%
Working interest		15.00%
Capital costs reimbursed to company from related party	$ 91	$ 138
Accounts receivable from related parties	3	47
Accounts payable from related parties	7	20
Investment Tranche One
Related party transactions
Funding from related party		$ 225
Investment Tranche Two
Related party transactions
Funding from related party	$ 225