Income Taxes - Effective Income Tax Expense (Benefit) Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense (benefit) at the federal statutory rate of 21%	$ (2,051)	$ (134)	$ 45
State income taxes (net of federal income tax benefit)	(41)	(21)	27
Partial release of valuation allowance due to the WildHorse Merger	0	(314)	0
Change in valuation allowance excluding impact of WildHorse Merger	2,010	114	(97)
Reorganization items	41	0	0
Equity-based compensation (non-officer)	10	4	4
Officer compensation limited under Section 162(m)	9	3	5
Other	3	17	6
Total Income Tax Expense (Benefit)	$ (19)	$ (331)	$ (10)