Debt and Credit Agreements - Cimarex Senior Notes (Details) - Senior Notes - USD ($) $ in Millions	Oct. 07, 2021	Oct. 01, 2021
Debt Instrument [Line Items]
Principal (In millions)	$ 1,800	$ 2,000
Fair Value		2,196
4.375% senior notes due June 1, 2024
Debt Instrument [Line Items]
Principal (In millions)		750
Fair Value		809
3.90% senior notes due May 15, 2027
Debt Instrument [Line Items]
Principal (In millions)		750
Fair Value		823
4.375% senior notes due March 15, 2029
Debt Instrument [Line Items]
Principal (In millions)		500
Fair Value		$ 564