Fair Value Measurements and Guarantees Recurring Measurements and Additional (Details) - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2024	Dec. 31, 2023		Dec. 31, 2022
Additional disclosures:
Collateral Already Posted, Aggregate Fair Value				$ 202
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
Subsequent Event [Member]
Additional disclosures:
Derivative Notional Amount Terminated	$ 750
Carrying Amount [Member]
Additional disclosures:
Long-term debt, including current portion		(25,713)		(22,554)
Guarantees		(37)		(38)
Fair Value [Member]
Additional disclosures:
Long-term debt, including current portion		(25,553)		(21,569)
Guarantees		(28)		(25)
Level 1 [Member]
Additional disclosures:
Long-term debt, including current portion		0		0
Guarantees		0		0
Collateral Already Posted, Aggregate Fair Value		2		202
Level 2 [Member]
Additional disclosures:
Long-term debt, including current portion		(25,553)		(21,569)
Guarantees		(12)		(9)
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		269		230
Derivative Asset, Fair Value, Gross Asset		310		166
Derivative Liability, Fair Value, Gross Liability		(285)		(810)
Interest Rate Derivatives, at Fair Value, Net		6
Financial Liabilities Fair Value Disclosure				(5)
Fair Value, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis
ARO Trust investments		269		230
Derivative Asset, Fair Value, Gross Asset		310		166
Derivative Liability, Fair Value, Gross Liability		(285)		(810)
Interest Rate Derivatives, at Fair Value, Net		6
Financial Liabilities Fair Value Disclosure				(5)
Fair Value, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis
ARO Trust investments		269		230
Derivative Asset, Fair Value, Gross Asset		141	[1]	20	[2]
Derivative Liability, Fair Value, Gross Liability		(3)	[1]	(22)	[2]
Interest Rate Derivatives, at Fair Value, Net		0
Financial Liabilities Fair Value Disclosure				0
Fair Value, Recurring [Member] | Level 2 [Member]
Measured on a recurring basis
ARO Trust investments		0		0
Derivative Asset, Fair Value, Gross Asset		112		132
Derivative Liability, Fair Value, Gross Liability		(278)		(718)
Interest Rate Derivatives, at Fair Value, Net		6
Financial Liabilities Fair Value Disclosure				(5)
Fair Value, Recurring [Member] | Level 3 [Member]
Measured on a recurring basis
ARO Trust investments		0		0
Derivative Asset, Fair Value, Gross Asset		57		14
Derivative Liability, Fair Value, Gross Liability		(4)		(70)
Interest Rate Derivatives, at Fair Value, Net		0
Financial Liabilities Fair Value Disclosure				$ 0
Wiltel Guarantee [Member]
Additional disclosures:
Guarantor Obligations, Maximum Exposure, Undiscounted		23
Indemnification Agreement [Member] | Carrying Amount [Member]
Additional disclosures:
Guarantees		$ 0

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

[2] Commodity derivative assets and liabilities exclude $202 million of net cash collateral in Level 1.