Employee Benefit Plans - Narrative (Details)		3 Months Ended	12 Months Ended
	Oct. 01, 2021 USD ($)	Dec. 31, 2021 USD ($) shares	Dec. 31, 2021 USD ($) Retiree shares	Dec. 31, 2020 USD ($) Retiree	Dec. 31, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Number of retirees and dependents | Retiree			364	337
Subsidy limit percentage of expected annual fully insured premium over age threshold			60.00%
Subsidy limit percentage of expected annual fully insured premium under age threshold			$ 648,000
Annual subsidy limit percentage increases for fully insured premium over age threshold			3.50%
Estimated contributions next year		$ 2,000,000	$ 2,000,000
Defined contribution cost recognized			1,000,000
Liabilities, including common stock		56,000,000	56,000,000	$ 31,000,000
Compensation (benefit) expense			$ 1,000,000	(1,000,000)	$ (2,000,000)
Cimarex
Restructuring Cost and Reserve [Line Items]
Distributions paid		27,000,000
Deferred compensation liability	$ 27,000,000
Executive Officer
Restructuring Cost and Reserve [Line Items]
Contributions to deferred compensation plan	$ 19,000,000
Savings Investment Plan
Restructuring Cost and Reserve [Line Items]
Employer matching percent			6.00%
Maximum contribution, percent of employee salary			10.00%
401(k) Plan
Restructuring Cost and Reserve [Line Items]
Employer matching percent			7.00%
Defined contribution cost recognized			$ 7,000,000	6,000,000	6,000,000
Deferred Compensation Plan
Restructuring Cost and Reserve [Line Items]
Market value of the trust assets, excluding common stock			47,000,000	22,000,000
Liabilities, including common stock		$ 56,000,000	$ 56,000,000	31,000,000
Number of common stock deferred into the rabbi trust (in shares) | shares		495,774	495,774
Common stock held in rabbi trust		$ 5,000,000	$ 5,000,000	5,000,000
Contributions to deferred compensation plan			$ 20,000,000	$ 1,000,000	$ 1,000,000