Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	$ 100	$ 60	$ 667	$ 2,150
Receivables, Net, Current	1,781	1,863
Inventory, Net	249	279
Other current assets and deferred charges	224	192
Property, Plant and Equipment, Net	39,155	38,692
Intangible assets – net of accumulated amortization	7,115	7,209
Other Assets, Noncurrent	1,819	1,830
Accounts payable	(1,551)	(1,613)
Other current liabilities	(1,289)	(1,360)
Other Liabilities and Deferred Revenue, Noncurrent	(5,189)	(5,268)
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents	35	15
Receivables, Net, Current	177	178
Inventory, Net	5	5
Other current assets and deferred charges	4	7
Property, Plant and Equipment, Net	4,867	4,896
Intangible assets – net of accumulated amortization	1,913	1,940
Other Assets, Noncurrent	27	27
Accounts payable	(56)	(57)
Other current liabilities	(32)	(29)
Other Liabilities and Deferred Revenue, Noncurrent	$ (268)	$ (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