Revenue Recognition Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Contract With Customer, Liability [Line Items]
Contract with Customer, Liability - Beginning of Period	$ 1,016	$ 1,053	$ 1,046	$ 1,081
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	86	75	120	117
Contract with Customer, Liability, Increase (Decrease) for Contract from Asset Purchase	23	0	23	0
Other Significant Noncash Transaction, Value of Consideration Received	2	2	4	4
Contract with Customer, Liability, Revenue Recognized	(73)	(66)	(139)	(138)
Contract with Customer, Liability - End of Period	1,054	1,064	1,054	1,064
Transcontinental Gas Pipe Line Company, LLC [Member]
Contract With Customer, Liability [Line Items]
Contract with Customer, Liability - Beginning of Period	171	181	173	184
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	0	0	0	0
Contract with Customer, Liability, Increase (Decrease) for Contract from Asset Purchase	0	0	0	0
Other Significant Noncash Transaction, Value of Consideration Received	0	0	0	0
Contract with Customer, Liability, Revenue Recognized	(3)	(2)	(5)	(5)
Contract with Customer, Liability - End of Period	168	179	168	179
Northwest Pipeline LLC [Member]
Contract With Customer, Liability [Line Items]
Contract with Customer, Liability - Beginning of Period	0	1	0	2
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Change in Measure of Progress	0	0	0	0
Contract with Customer, Liability, Increase (Decrease) for Contract from Asset Purchase	0	0	0	0
Other Significant Noncash Transaction, Value of Consideration Received	0	0	0	0
Contract with Customer, Liability, Revenue Recognized	0	0	0	(1)
Contract with Customer, Liability - End of Period	$ 0	$ 1	$ 0	$ 1