Derivative Financial Instruments (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions		Jun. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Derivative Asset, Current	[1]	$ 61	$ 63
Derivative Asset, Noncurrent	[1]	212	309
Derivative Liability, Current		3	0
Derivative Liability, Noncurrent		5	1
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Current		$ 61	$ 63
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration]		Other Assets, Current	Other Assets, Current
Derivative Asset, Noncurrent		$ 212	$ 309
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Regulated Entity, Other Assets, Noncurrent	Regulated Entity, Other Assets, Noncurrent
Derivative Assets		$ 273	$ 372
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Assets	Assets
Derivative Liability, Current		$ 3	$ 0
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration]		Liabilities, Current	Liabilities, Current
Derivative Liability, Noncurrent		$ 5	$ 1
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Liabilities, Noncurrent	Liabilities, Noncurrent
Derivative Liability		$ 8	$ 1
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Liabilities and Equity	Liabilities and Equity
Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Derivative [Line Items]
Derivative Asset, Current		$ 61	$ 63
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration]		Other Assets, Current	Other Assets, Current
Derivative Asset, Noncurrent		$ 210	$ 307
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Regulated Entity, Other Assets, Noncurrent	Regulated Entity, Other Assets, Noncurrent
Derivative Liability, Current		$ 3	$ 0
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration]		Liabilities, Current	Liabilities, Current
Derivative Liability, Noncurrent		$ 4	$ 0
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Liabilities, Noncurrent	Liabilities, Noncurrent
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Noncurrent		$ 2	$ 2
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Regulated Entity, Other Assets, Noncurrent	Regulated Entity, Other Assets, Noncurrent
Derivative Liability, Noncurrent		$ 1	$ 1
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]		Liabilities, Noncurrent	Liabilities, Noncurrent

[1] See Note 12 for amounts attributable to affiliates.