Variable Interest Entities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	$ 903	$ 60	$ 55	$ 2,150
Receivables, Net, Current	1,563	1,863
Inventory, Net	335	279
Other current assets and deferred charges	218	192
Property, Plant and Equipment, Net	39,773	38,692
Intangible assets – net	7,100	7,209
Other Assets, Noncurrent	1,838	1,830
Accounts payable	(1,414)	(1,613)
Other current liabilities	(1,521)	(1,360)
Other Liabilities and Deferred Revenue, Noncurrent	(5,158)	(5,268)
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	72	15
Receivables, Net, Current	178	178
Inventory, Net	6	5
Other current assets and deferred charges	3	7
Property, Plant and Equipment, Net	4,846	4,896
Intangible assets – net	1,886	1,940
Other Assets, Noncurrent	24	27
Accounts payable	(73)	(57)
Other current liabilities	(37)	(29)
Other Liabilities and Deferred Revenue, Noncurrent	$ (266)	$ (263)
Variable Interest Entity, Primary Beneficiary [Member] | Williams Companies Inc [Member] | Northeast JV [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	65.00%
Variable Interest Entity, Primary Beneficiary [Member] | Williams Companies Inc [Member] | Gulfstar One [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	51.00%
Variable Interest Entity, Primary Beneficiary [Member] | Williams Companies Inc [Member] | Cardinal Gas Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	66.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | Williams Companies Inc [Member]
Variable Interest Entity [Line Items]
Equity-method investments	$ 214