Contingencies (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 42		$ 42
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]		Other Liabilities and Deferred Revenue, Noncurrent, Other current liabilities		Other Liabilities and Deferred Revenue, Noncurrent, Other current liabilities
Other current liabilities		$ 1,521		$ 1,521		$ 1,360
Transcontinental Gas Pipe Line Company, LLC [Member]
Loss Contingencies [Line Items]
Regulatory Assets, Current		124		124		74
Other current liabilities		295		295		181
Interest Income, Other		7	$ 15	15	$ 33
Transcontinental Gas Pipe Line Company, LLC [Member] | Environmental Restoration Costs
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 10		$ 10
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]		Other current liabilities, Other Liabilities, Noncurrent		Other current liabilities, Other Liabilities, Noncurrent
Transcontinental Gas Pipe Line Company, LLC [Member] | Potentially Responsible Party At Various Superfund And State Waste Disposal Sites | Maximum [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross		$ 1		$ 1
Northwest Pipeline LLC [Member]
Loss Contingencies [Line Items]
Regulatory Assets, Current		4		4		6
Other current liabilities		29		29		34
Interest Income, Other				2	$ 1
Northwest Pipeline LLC [Member] | Environmental Restoration Costs
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 1		$ 1
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]		Other current liabilities, Other Liabilities, Noncurrent		Other current liabilities, Other Liabilities, Noncurrent
Northwest Pipeline LLC [Member] | Washington State Climate Commitment Act
Loss Contingencies [Line Items]
Regulatory Assets, Current		$ 54		$ 54		38
Other current liabilities		4		4		$ 3
Gas Pipeline [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		11		11
Recoverable through rates [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		3		3
Natural Gas Underground Storage Facilities [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		7		7
Former Operations [Member]
Loss Contingencies [Line Items]
Accrued environmental loss liabilities		$ 24		$ 24
Construction Project | Transcontinental Gas Pipe Line Company, LLC [Member]
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded to Other Party	$ 110
Loss Contingency Expected Recovery Percentage	29.00%