Related Party Transactions - Transco and NWP (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2025	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Related Party Transaction [Line Items]
Accounts payable		$ 1,551		$ 1,613
Related Party Transaction, Rate		4.00%
Revenues		$ 3,048	$ 2,771
Transcontinental Gas Pipe Line Company, LLC [Member]
Related Party Transaction [Line Items]
Interest Income, Other		8	18
Revenues		770	732
Credit To Expenses From Affiliates		0	2
Cash distributions to parent		246	320
Transcontinental Gas Pipe Line Company, LLC [Member] | Affiliated Entity
Related Party Transaction [Line Items]
Accounts and Financing Receivable, after Allowance for Credit Loss, Current		567		638
Interest Income, Other		6	16
Revenues		20	19
Related Party Transaction, Purchases from Related Party		2	2
Operating Expenses		92	85
Transcontinental Gas Pipe Line Company, LLC [Member] | Affiliated Entity | Subsequent Event [Member]
Related Party Transaction [Line Items]
Cash distributions to parent	$ 360
Northwest Pipeline LLC [Member]
Related Party Transaction [Line Items]
Interest Income, Other		1	1
Revenues		111	117
Operating Expenses		61	61
Cash distributions to parent		24	33
Northwest Pipeline LLC [Member] | Affiliated Entity
Related Party Transaction [Line Items]
Accounts and Financing Receivable, after Allowance for Credit Loss, Current		62
Accounts payable		0		$ 26
Interest Income, Other			2
Operating Expenses		$ 24	$ 22
Northwest Pipeline LLC [Member] | Affiliated Entity | Subsequent Event [Member]
Related Party Transaction [Line Items]
Cash distributions to parent	40
Williams Companies Inc [Member] | Affiliated Entity | Subsequent Event [Member]
Related Party Transaction [Line Items]
Cash distributions to parent	$ 46