Fair Value Measurements and Guarantees Recurring Measurements and Additional (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Jan. 31, 2024	Jun. 30, 2024		Dec. 31, 2023
Additional disclosures:
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Other Assets, Noncurrent
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Other Liabilities and Deferred Revenue, Noncurrent
Derivative, Notional Amount				$ 1,150
Derivative Notional Amount Terminated	$ 750
Derivative, Additional Notional Amount		$ 200
Carrying Amount [Member]
Additional disclosures:
Long-term debt, including current portion		(25,632)		(25,713)
Guarantees		(36)		(37)
Fair Value [Member]
Additional disclosures:
Long-term debt, including current portion		(24,884)		(25,553)
Guarantees		(29)		(28)
Level 1 [Member]
Additional disclosures:
Long-term debt, including current portion		0		0
Guarantees		0		0
Collateral Already Posted, Aggregate Fair Value		143		2
Level 2 [Member]
Additional disclosures:
Long-term debt, including current portion		(24,884)		(25,553)
Guarantees		(13)		(12)
Level 3 [Member]
Additional disclosures:
Long-term debt, including current portion		0		0
Guarantees		(16)		(16)
Fair Value, Recurring [Member] | Carrying Amount [Member]
Measured on a recurring basis
ARO Trust investments		283		269
Derivative Asset, Fair Value, Gross Asset		109		310
Derivative Liability, Fair Value, Gross Liability		(310)		(285)
Interest Rate Derivatives, at Fair Value, Net		2		6
Fair Value, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis
ARO Trust investments		283		269
Derivative Asset, Fair Value, Gross Asset		109		310
Derivative Liability, Fair Value, Gross Liability		(310)		(285)
Interest Rate Derivatives, at Fair Value, Net		2		6
Fair Value, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis
ARO Trust investments		283		269
Derivative Asset, Fair Value, Gross Asset		0	[1]	141	[2]
Derivative Liability, Fair Value, Gross Liability		(2)	[1]	(3)	[2]
Interest Rate Derivatives, at Fair Value, Net		0		0
Fair Value, Recurring [Member] | Level 2 [Member]
Measured on a recurring basis
ARO Trust investments		0		0
Derivative Asset, Fair Value, Gross Asset		55		112
Derivative Liability, Fair Value, Gross Liability		(304)		(278)
Interest Rate Derivatives, at Fair Value, Net		2		6
Fair Value, Recurring [Member] | Level 3 [Member]
Measured on a recurring basis
ARO Trust investments		0		0
Derivative Asset, Fair Value, Gross Asset		54		57
Derivative Liability, Fair Value, Gross Liability		(4)		(4)
Interest Rate Derivatives, at Fair Value, Net		0		$ 0
Wiltel Guarantee [Member]
Additional disclosures:
Guarantor Obligations, Maximum Exposure, Undiscounted		22
Indemnification Agreement [Member] | Carrying Amount [Member]
Additional disclosures:
Guarantees		$ 0

[1] Commodity derivative assets and liabilities exclude $143 million of net cash collateral in Level 1.

[2] Commodity derivative assets and liabilities exclude $2 million of net cash collateral in Level 1.