Regulatory Assets and Liabilities - Transco (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets	$ 666	$ 622
Regulatory Liability [Line Items]
Regulatory Liability, Current	85	77
Regulatory Liabilities	1,385	1,365
Transcontinental Gas Pipe Line Company, LLC [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	74	87
Regulatory Assets, Noncurrent	320	299
Regulatory Assets	394	386
Regulatory Liability [Line Items]
Regulatory Liability, Current	58	49
Regulatory Liabilities, Noncurrent	976	956
Regulatory Liabilities	1,034	1,005
Transcontinental Gas Pipe Line Company, LLC [Member] | Deferred Income Tax Charge
Regulatory Liability [Line Items]
Regulatory Liability, Current	31	31
Regulatory Liabilities, Noncurrent	252	283
Regulatory Liabilities	13
Transcontinental Gas Pipe Line Company, LLC [Member] | Postretirement Benefit Costs
Regulatory Liability [Line Items]
Regulatory Liability, Current	0	8
Regulatory Liabilities, Noncurrent	31	23
Transcontinental Gas Pipe Line Company, LLC [Member] | Electric Power Cost
Regulatory Liability [Line Items]
Regulatory Liability, Current	26	7
Transcontinental Gas Pipe Line Company, LLC [Member] | Pension Costs
Regulatory Liability [Line Items]
Regulatory Liability, Current	0	2
Regulatory Liabilities, Noncurrent	30	24
Transcontinental Gas Pipe Line Company, LLC [Member] | Other Regulatory Assets (Liabilities)
Regulatory Liability [Line Items]
Regulatory Liability, Current	1	1
Regulatory Liabilities, Noncurrent	24	14
Transcontinental Gas Pipe Line Company, LLC [Member] | Removal Costs
Regulatory Liability [Line Items]
Regulatory Liabilities, Noncurrent	632	605
Transcontinental Gas Pipe Line Company, LLC [Member] | Sentinel Meter Station Depreciation
Regulatory Liability [Line Items]
Regulatory Liabilities, Noncurrent	7	7
Transcontinental Gas Pipe Line Company, LLC [Member] | Fuel Cost
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	47	60
Transcontinental Gas Pipe Line Company, LLC [Member] | Asset Retirement Obligation Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	16	16
Regulatory Assets, Noncurrent	243	209
Transcontinental Gas Pipe Line Company, LLC [Member] | Deferred Cash Out
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	6	6
Regulatory Assets, Noncurrent	0	11
Transcontinental Gas Pipe Line Company, LLC [Member] | Asset Retirement Costs - Eminence
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	5	5
Regulatory Assets, Noncurrent	15	20
Transcontinental Gas Pipe Line Company, LLC [Member] | Deferred Taxes On Equity Funds Used During Construction
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent	29	31
Transcontinental Gas Pipe Line Company, LLC [Member] | Slug Catcher
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent	6	6
Transcontinental Gas Pipe Line Company, LLC [Member] | Other Regulatory Assets (Liabilities)
Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent	$ 27	$ 22