Balance Sheet (Unaudited) - Transco - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Assets, Current [Abstract]
Cash and cash equivalents	$ 100	$ 60
Inventory, Net	249	279
Other current assets and deferred charges	224	192
Current assets	2,535	2,661
Property, Plant and Equipment, Gross	58,313	57,395
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(19,158)	(18,703)
Property, Plant and Equipment, Net	39,155	38,692
Other Assets, Noncurrent	1,819	1,830
Total assets	54,924	54,532
Liabilities, Current [Abstract]
Accounts payable	1,551	1,613
Other current liabilities	1,289	1,360
Total current liabilities	6,266	5,312
Contingent liabilities and commitments
Members' Equity [Abstract]
Retained Earnings (Accumulated Deficit)	(12,320)	(12,396)
Total liabilities and equity	54,924	54,532
Transcontinental Gas Pipe Line Company, LLC [Member]
Assets, Current [Abstract]
Cash and cash equivalents	0	0
Accounts and Other Receivables, Net, Current	10	12
Inventory, Net	90	81
Regulatory Assets, Current	122	74
Other current assets and deferred charges	24	24
Current assets	1,089	1,103
Property, Plant and Equipment, Gross	20,222	20,044
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(6,119)	(5,941)
Property, Plant and Equipment, Net	14,103	14,103
Regulatory Assets, Noncurrent	276	320
Other Assets, Noncurrent	430	405
Total assets	15,898	15,931
Liabilities, Current [Abstract]
Accounts Payable, Trade, Current	182	258
Regulatory Liability, Current	65	58
Other current liabilities	181	181
Asset Retirement Obligation, Current	58	22
Long-Term Debt, Current Maturities	1,034	35
Total current liabilities	1,571	609
Long-Term Debt, Excluding Current Maturities	4,195	5,200
Regulatory Liabilities, Noncurrent	929	976
Asset Retirement Obligations, Noncurrent	560	593
Other Liabilities, Noncurrent	263	248
Contingent liabilities and commitments
Members' Equity [Abstract]
Members' Capital	5,088	5,088
Retained Earnings (Accumulated Deficit)	3,292	3,217
Total Members' Equity	8,380	8,305
Total liabilities and equity	15,898	15,931
Transcontinental Gas Pipe Line Company, LLC [Member] | Related Party
Assets, Current [Abstract]
Accounts and Financing Receivable, after Allowance for Credit Loss, Current	567	638
Accounts Receivable, after Allowance for Credit Loss, Current	7	24
Liabilities, Current [Abstract]
Accounts payable	51	55
Transcontinental Gas Pipe Line Company, LLC [Member] | Nonrelated Party
Assets, Current [Abstract]
Accounts Receivable, after Allowance for Credit Loss, Current	$ 269	$ 250