Fair Value Measurements and Guarantees (Tables)

6 Months Ended

Jun. 30, 2025

Fair Value Assets and Liabilities Measured On Recurring Basis [Table Text Block]

The following table presents, by level within the fair value hierarchy, certain of Williams’, Transco’s, and NWP’s significant financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, accounts payable, and commercial paper approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table.


					Fair Value Measurements Using
	Carrying Amount		Fair Value		Quoted Prices In Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(Millions)
Assets (liabilities) at June 30, 2025:
Measured on a recurring basis:
ARO Trust investments - Transco	$	323	$	323	$	323	$	—	$	—
Commodity derivative assets (1)	265		609		421		136		52
Commodity derivative liabilities (1)	(336)		(949)		(522)		(380)		(47)


Additional disclosures:


Guarantees	(35)		(28)		—		(12)		(16)
Debt by issuer, including current portion:
Williams	(22,394)		(21,941)		—		(21,941)		—
Transco	(5,221)		(5,254)		—		(5,254)		—
NWP	(583)		(579)		—		(579)		—
MountainWest	(374)		(373)		—		(373)		—
Total debt	(28,572)		(28,147)		—		(28,147)		—

Assets (liabilities) at December 31, 2024:
Measured on a recurring basis:
ARO Trust investments - Transco	$	297	$	297	$	297	$	—	$	—
Commodity derivative assets (1)	344		726		427		188		111
Commodity derivative liabilities (1)	(400)		(1,070)		(532)		(475)		(63)

Additional disclosures:

Guarantees	(36)		(28)		—		(12)		(16)
Debt by issuer, including current portion:
Williams	(20,167)		(19,517)		—		(19,517)		—
Transco	(5,235)		(5,276)		—		(5,276)		—
NWP	(582)		(573)		—		(573)		—
MountainWest	(372)		(364)		—		(364)		—
Gulf Coast Storage deferred consideration (Note 3)	(100)		(100)		—		(100)		—
Total debt	(26,456)		(25,830)		—		(25,830)		—

(1)The carrying amount is presented net of counterparty offsetting arrangements and collateral (see Note 9 – Commodity Derivatives).

Debt Securities, Trading, and Equity Securities, FV-NI

Transco investments within the ARO Trust were as follows:


	June 30, 2025				December 31, 2024
	Amortized Cost Basis		Fair Value		Amortized Cost Basis		Fair Value
	(Millions)
Money Market Funds	$	24	$	24	$	27	$	27
U.S. Equity Funds	53		153		53		146
International Equity Funds	32		47		32		40
Municipal Bond Funds	104		99		88		84
Total	$	213	$	323	$	200	$	297