Fair Value Measurements Concentration of Credit Risk (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024		Dec. 31, 2023	Dec. 31, 2022
Concentration Risk [Line Items]
Receivables, Net, Current	$ 1,863		$ 1,655
Revenues	10,503		10,907	$ 10,965
Transcontinental Gas Pipe Line Company, LLC [Member]
Concentration Risk [Line Items]
Revenues	2,964		2,866	2,909
Transcontinental Gas Pipe Line Company, LLC [Member] | Dominion Energy, Inc
Concentration Risk [Line Items]
Revenues	217	[1]	287	293
Northwest Pipeline LLC [Member]
Concentration Risk [Line Items]
Revenues	444		440	448
Northwest Pipeline LLC [Member] | Puget Sound Energy, Inc
Concentration Risk [Line Items]
Revenues	136		126	131
Northwest Pipeline LLC [Member] | Cascade Natural Gas Corporation
Concentration Risk [Line Items]
Revenues	46		47	49
Northwest Pipeline LLC [Member] | Northwest Natural Gas Company
Concentration Risk [Line Items]
Revenues	47		47	$ 49
NGLs, natural gas, and related products and services [Member]
Concentration Risk [Line Items]
Receivables, Net, Current	594		589
Transportation of natural gas and related products [Member]
Concentration Risk [Line Items]
Receivables, Net, Current	339		310
Marketing Of Natural Gas And NGLs
Concentration Risk [Line Items]
Receivables, Net, Current	516		321
Oil and Gas, Exploration and Production
Concentration Risk [Line Items]
Receivables, Net, Current	45		72
Accounts Receivable related to revenues from contracts with customers [Member]
Concentration Risk [Line Items]
Receivables, Net, Current	1,494		1,292
Derivative Receivables
Concentration Risk [Line Items]
Receivables, Net, Current	294		311
Other Receivable [Member]
Concentration Risk [Line Items]
Receivables, Net, Current	$ 75		$ 52

[1] The 2024 amount is less than 10 percent of Transco’s revenue