Segment Disclosures Recon from Segment to Consolidated - Revenues, Modified EBITDA, and Significant Expenses (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment revenues [Line Items]
Revenues		$ 2,781	$ 2,336	$ 5,829	$ 5,107
Other financial information:
Proportional Modified EBITDA Equity Method Investments		(231)	(238)	(467)	(466)
Depreciation, Depletion and Amortization		(605)	(540)	(1,190)	(1,088)
Income (Loss) from Equity Method Investments		142	147	297	284
Other investing income (loss) - net		4	18	12	42
Interest expense		(350)	(339)	(699)	(688)
Asset Retirement Obligation Accretion Expense For Nonregulated Operations		(24)	(21)	(48)	(39)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		757	555	1,679	1,410
Energy Related Derivative | Not Designated as Hedging Instrument [Member] | Cost of Sales
Other financial information:
Unrealized Gain (Loss) on Derivatives		12	(7)	2	(4)
Service [Member]
Segment revenues [Line Items]
Revenues		2,041	1,837	4,044	3,742
NonRegulated Service Commodity Consideration [Member]
Segment revenues [Line Items]
Revenues		47	18	96	48
Product [Member]
Segment revenues [Line Items]
Revenues		657	610	1,715	1,455
Energy Commodities and Service
Segment revenues [Line Items]
Revenues		36	(129)	(26)	(138)
Operating Segments [Member] | Transmission And Gulf Of America [Member]
Segment revenues [Line Items]
Revenues		1,312	1,068	2,584	2,187
Other financial information:
Product Costs And Net Realized Processing Commodity Expenses		(119)	(40)	(242)	(101)
Operating And Administrative Expenses	[1]	(286)	(260)	(556)	(515)
Recovery of Direct Costs	[2]	(55)	(62)	(125)	(126)
Other Segment Income (Expenses) - Net	[3]	2	53	15	97
Proportional Modified EBITDA Equity Method Investments		37	49	73	95
Modified EBITDA		891	808	1,749	1,637
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Energy Related Derivative | Not Designated as Hedging Instrument [Member] | Cost of Sales
Other financial information:
Unrealized Gain (Loss) on Derivatives		0	0	0	0
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Service [Member]
Segment revenues [Line Items]
Revenues		1,176	1,023	2,311	2,072
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Service [Member] | External Customer
Segment revenues [Line Items]
Revenues		1,150	999	2,263	2,028
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Service [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		26	24	48	44
Operating Segments [Member] | Transmission And Gulf Of America [Member] | NonRegulated Service Commodity Consideration [Member]
Segment revenues [Line Items]
Revenues		28	5	51	14
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Product [Member]
Segment revenues [Line Items]
Revenues		108	40	223	101
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Product [Member] | External Customer
Segment revenues [Line Items]
Revenues		31	25	57	55
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Product [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		77	15	166	46
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Energy Commodities and Service
Segment revenues [Line Items]
Revenues	[4]	0	0	(1)	0
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Energy Commodities and Service | Realized Gain (Loss)
Segment revenues [Line Items]
Revenues		0	0	(1)	0
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Energy Commodities and Service | Unrealized Gain (Loss)
Segment revenues [Line Items]
Revenues		0	0	0	0
Operating Segments [Member] | Northeast G And P [Member]
Segment revenues [Line Items]
Revenues		541	483	1,096	992
Other financial information:
Product Costs And Net Realized Processing Commodity Expenses		(38)	(18)	(90)	(37)
Operating And Administrative Expenses	[1]	(113)	(108)	(219)	(216)
Recovery of Direct Costs	[2]	(41)	(32)	(83)	(66)
Other Segment Income (Expenses) - Net	[3]	(2)	3	(2)	2
Proportional Modified EBITDA Equity Method Investments		154	153	313	310
Modified EBITDA		501	481	1,015	985
Operating Segments [Member] | Northeast G And P [Member] | Energy Related Derivative | Not Designated as Hedging Instrument [Member] | Cost of Sales
Other financial information:
Unrealized Gain (Loss) on Derivatives		0	0	0	0
Operating Segments [Member] | Northeast G And P [Member] | Service [Member]
Segment revenues [Line Items]
Revenues		497	465	994	944
Operating Segments [Member] | Northeast G And P [Member] | Service [Member] | External Customer
Segment revenues [Line Items]
Revenues		494	462	987	937
Operating Segments [Member] | Northeast G And P [Member] | Service [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		3	3	7	7
Operating Segments [Member] | Northeast G And P [Member] | NonRegulated Service Commodity Consideration [Member]
Segment revenues [Line Items]
Revenues		0	(5)	1	0
Operating Segments [Member] | Northeast G And P [Member] | Product [Member]
Segment revenues [Line Items]
Revenues		44	23	101	48
Operating Segments [Member] | Northeast G And P [Member] | Product [Member] | External Customer
Segment revenues [Line Items]
Revenues		17	5	35	7
Operating Segments [Member] | Northeast G And P [Member] | Product [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		27	18	66	41
Operating Segments [Member] | Northeast G And P [Member] | Energy Commodities and Service
Segment revenues [Line Items]
Revenues	[4]	0	0	0	0
Operating Segments [Member] | Northeast G And P [Member] | Energy Commodities and Service | Realized Gain (Loss)
Segment revenues [Line Items]
Revenues		0	0	0	0
Operating Segments [Member] | Northeast G And P [Member] | Energy Commodities and Service | Unrealized Gain (Loss)
Segment revenues [Line Items]
Revenues		0	0	0	0
Operating Segments [Member] | West [Member]
Segment revenues [Line Items]
Revenues		676	621	1,401	1,322
Other financial information:
Product Costs And Net Realized Processing Commodity Expenses		(201)	(177)	(455)	(426)
Operating And Administrative Expenses	[1]	(150)	(148)	(302)	(287)
Recovery of Direct Costs	[2]	(15)	(12)	(29)	(23)
Other Segment Income (Expenses) - Net	[3]	(1)	(2)	10	(2)
Proportional Modified EBITDA Equity Method Investments		32	36	70	61
Modified EBITDA		341	318	695	645
Operating Segments [Member] | West [Member] | Energy Related Derivative | Not Designated as Hedging Instrument [Member] | Cost of Sales
Other financial information:
Unrealized Gain (Loss) on Derivatives		0	0	0	0
Operating Segments [Member] | West [Member] | Service [Member]
Segment revenues [Line Items]
Revenues		446	407	884	844
Operating Segments [Member] | West [Member] | Service [Member] | External Customer
Segment revenues [Line Items]
Revenues		393	372	786	769
Operating Segments [Member] | West [Member] | Service [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		53	35	98	75
Operating Segments [Member] | West [Member] | NonRegulated Service Commodity Consideration [Member]
Segment revenues [Line Items]
Revenues		19	18	44	34
Operating Segments [Member] | West [Member] | Product [Member]
Segment revenues [Line Items]
Revenues		210	191	474	439
Operating Segments [Member] | West [Member] | Product [Member] | External Customer
Segment revenues [Line Items]
Revenues		31	34	71	106
Operating Segments [Member] | West [Member] | Product [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		179	157	403	333
Operating Segments [Member] | West [Member] | Energy Commodities and Service
Segment revenues [Line Items]
Revenues	[4]	1	5	(1)	5
Operating Segments [Member] | West [Member] | Energy Commodities and Service | Realized Gain (Loss)
Segment revenues [Line Items]
Revenues		1	5	(1)	5
Operating Segments [Member] | West [Member] | Energy Commodities and Service | Unrealized Gain (Loss)
Segment revenues [Line Items]
Revenues		0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services
Segment revenues [Line Items]
Revenues	[5]	389	291	1,100	861
Other financial information:
Product Costs And Net Realized Processing Commodity Expenses		(421)	(387)	(934)	(819)
Operating And Administrative Expenses	[1]	(19)	(23)	(58)	(63)
Recovery of Direct Costs	[2]	0	0	0	0
Other Segment Income (Expenses) - Net	[3]	1	0	1	0
Proportional Modified EBITDA Equity Method Investments		8	0	11	0
Modified EBITDA		(30)	(126)	122	(25)
Operating Segments [Member] | Gas & NGL Marketing Services | Energy Related Derivative | Not Designated as Hedging Instrument [Member] | Cost of Sales
Other financial information:
Unrealized Gain (Loss) on Derivatives		12	(7)	2	(4)
Operating Segments [Member] | Gas & NGL Marketing Services | Service [Member]
Segment revenues [Line Items]
Revenues	[5]	0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | Service [Member] | External Customer
Segment revenues [Line Items]
Revenues	[5]	0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | Service [Member] | Internal Customer
Segment revenues [Line Items]
Revenues	[5]	0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | NonRegulated Service Commodity Consideration [Member]
Segment revenues [Line Items]
Revenues	[5]	0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | Product [Member]
Segment revenues [Line Items]
Revenues	[5]	403	423	1,142	1,010
Operating Segments [Member] | Gas & NGL Marketing Services | Product [Member] | External Customer
Segment revenues [Line Items]
Revenues	[5]	529	508	1,461	1,215
Operating Segments [Member] | Gas & NGL Marketing Services | Product [Member] | Internal Customer
Segment revenues [Line Items]
Revenues	[5]	(126)	(85)	(319)	(205)
Operating Segments [Member] | Gas & NGL Marketing Services | Energy Commodities and Service
Segment revenues [Line Items]
Revenues	[4],[5]	(14)	(132)	(42)	(149)
Operating Segments [Member] | Gas & NGL Marketing Services | Energy Commodities and Service | Realized Gain (Loss)
Segment revenues [Line Items]
Revenues	[5]	2	(33)	(33)	48
Operating Segments [Member] | Gas & NGL Marketing Services | Energy Commodities and Service | Unrealized Gain (Loss)
Segment revenues [Line Items]
Revenues	[5]	(16)	(99)	(9)	(197)
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment
Segment revenues [Line Items]
Revenues		2,918	2,463	6,181	5,362
Other financial information:
Modified EBITDA		1,703	1,481	3,581	3,242
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Service [Member]
Segment revenues [Line Items]
Revenues		2,119	1,895	4,189	3,860
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Service [Member] | External Customer
Segment revenues [Line Items]
Revenues		2,037	1,833	4,036	3,734
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Service [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		82	62	153	126
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | NonRegulated Service Commodity Consideration [Member]
Segment revenues [Line Items]
Revenues		47	18	96	48
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Product [Member]
Segment revenues [Line Items]
Revenues		765	677	1,940	1,598
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Product [Member] | External Customer
Segment revenues [Line Items]
Revenues		608	572	1,624	1,383
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Product [Member] | Internal Customer
Segment revenues [Line Items]
Revenues		157	105	316	215
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Energy Commodities and Service
Segment revenues [Line Items]
Revenues	[4]	(13)	(127)	(44)	(144)
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Energy Commodities and Service | Realized Gain (Loss)
Segment revenues [Line Items]
Revenues		3	(28)	(35)	53
Operating Segments [Member] | Reportable Segment, Aggregation before Other Operating Segment | Energy Commodities and Service | Unrealized Gain (Loss)
Segment revenues [Line Items]
Revenues		(16)	(99)	(9)	(197)
Corporate, Non-Segment | Other Operating Segment
Segment revenues [Line Items]
Revenues		190	88	318	208
Other financial information:
Modified EBITDA		118	47	193	123
Intersegment Eliminations [Member]
Segment revenues [Line Items]
Revenues		$ (327)	$ (215)	$ (670)	$ (463)

[1] Segment operating and administrative expenses primarily include payroll, maintenance and operating costs and taxes, and general and administrative expenses, including acquisition and transition-related expenses. It also includes project execution, information technology, finance and accounting, real estate and aviation, central engineering services, safety and operational discipline, supply chain and digital transformation, corporate strategic development, human resources, legal and government affairs, and executive and audit support services costs which are centrally managed and allocated to segments.

[2] Recoverable power, transportation and storage costs are charges incurred which are reimbursable pursuant to FERC stipulations or customer contracts.

[3] Other segment income (expenses) primarily includes equity AFUDC and regulatory credits and charges related to Williams’ regulated operations.

[4] Williams records transactions that qualify as commodity derivatives at fair value with changes in fair value recognized in earnings in the period of change and characterized as unrealized gains or losses. Gains and losses from commodity derivatives held for energy trading purposes are presented on a net basis in revenue.

[5] As Williams is acting as agent for natural gas marketing customers or engages in energy trading activities, the resulting revenues are presented net of the related costs of those activities.