Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 1,001	$ 707
Derivative Liabilities	(941)	(597)
Balance Sheet Location [Axis]: us-gaap:DerivativeAssetsCurrent
Derivatives, Fair Value [Line Items]
Derivative Assets	767	482
Balance Sheet Location [Axis]: us-gaap:DerivativeAssetsNoncurrent
Derivatives, Fair Value [Line Items]
Derivative Assets	234	225
Balance Sheet Location [Axis]: us-gaap:DerivativeLiabilitiesCurrent
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(739)	(413)
Balance Sheet Location [Axis]: us-gaap:DerivativeLiabilitiesNoncurrent
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(202)	(184)
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	14	3
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	1	0
Derivative Liabilities	(1)	(1)
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	293	372
Derivative Liabilities	(313)	(329)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	608	275
Derivative Liabilities	(578)	(235)
Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	85	57
Derivative Liabilities	(49)	(32)
Derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	14	3
Derivative Liabilities	0	(1)
Derivatives designated as hedging instruments \| Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	14	3
Derivative Liabilities	0	0
Derivatives designated as hedging instruments \| Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	0	(1)
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	987	704
Derivative Liabilities	(941)	(596)
Derivatives not designated as hedging instruments \| Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	1	0
Derivative Liabilities	(1)	0
Derivatives not designated as hedging instruments \| Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	293	372
Derivative Liabilities	(313)	(329)
Derivatives not designated as hedging instruments \| Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	609	275
Derivative Liabilities	(578)	(235)
Derivatives not designated as hedging instruments \| Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	84	57
Derivative Liabilities	$ (49)	$ (32)