Revenue by Category (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 3,378	$ 2,847	$ 7,565	$ 6,186
Revenue Not from Contract with Customer, Other	[1]	671	363	1,758	1,231
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	(1,268)	(874)	(3,494)	(2,310)
Total revenues		2,781	2,336	5,829	5,107
Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		906	826	1,806	1,685
NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,072	953	2,111	1,934
NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		47	18	96	48
Total revenues		47	18	96	48
Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		38	35	81	73
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		2,063	1,832	4,094	3,740
Total revenues		2,041	1,837	4,044	3,742
Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,315	1,015	3,471	2,446
Total revenues		657	610	1,715	1,455
Operating Segments [Member] | Transmission And Gulf Of America [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,302	1,060	2,569	2,168
Revenue Not from Contract with Customer, Other	[1]	10	8	15	19
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	0	0	0	0
Total revenues		1,312	1,068	2,584	2,187
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		927	846	1,847	1,726
Operating Segments [Member] | Transmission And Gulf Of America [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		226	158	418	303
Operating Segments [Member] | Transmission And Gulf Of America [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		28	5	51	14
Total revenues		28	5	51	14
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		13	11	30	24
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,194	1,020	2,346	2,067
Total revenues		1,176	1,023	2,311	2,072
Operating Segments [Member] | Transmission And Gulf Of America [Member] | Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		108	40	223	101
Total revenues		108	40	223	101
Operating Segments [Member] | Northeast G And P [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		529	472	1,073	970
Revenue Not from Contract with Customer, Other	[1]	12	11	23	22
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	0	0	0	0
Total revenues		541	483	1,096	992
Operating Segments [Member] | Northeast G And P [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Operating Segments [Member] | Northeast G And P [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		460	431	922	875
Operating Segments [Member] | Northeast G And P [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	(5)	1	0
Total revenues		0	(5)	1	0
Operating Segments [Member] | Northeast G And P [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		25	23	49	47
Operating Segments [Member] | Northeast G And P [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		485	449	972	922
Total revenues		497	465	994	944
Operating Segments [Member] | Northeast G And P [Member] | Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		44	23	101	48
Total revenues		44	23	101	48
Operating Segments [Member] | West [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		675	615	1,401	1,315
Revenue Not from Contract with Customer, Other	[1]	1	6	0	7
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	0	0	0	0
Total revenues		676	621	1,401	1,322
Operating Segments [Member] | West [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Operating Segments [Member] | West [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		441	401	871	831
Operating Segments [Member] | West [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		19	18	44	34
Total revenues		19	18	44	34
Operating Segments [Member] | West [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		5	5	12	11
Operating Segments [Member] | West [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		465	424	927	876
Total revenues		446	407	884	844
Operating Segments [Member] | West [Member] | Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		210	191	474	439
Total revenues		210	191	474	439
Operating Segments [Member] | Gas & NGL Marketing Services
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,213	922	3,269	2,228
Revenue Not from Contract with Customer, Other	[1]	596	337	1,696	1,170
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	(1,420)	(968)	(3,865)	(2,537)
Total revenues	[3]	389	291	1,100	861
Operating Segments [Member] | Gas & NGL Marketing Services | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Total revenues	[3]	0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Total revenues	[3]	0	0	0	0
Operating Segments [Member] | Gas & NGL Marketing Services | Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		1,213	922	3,269	2,228
Total revenues	[3]	403	423	1,142	1,010
Corporate, Non-Segment | Other Operating Segment
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		137	86	292	194
Revenue Not from Contract with Customer, Other	[1]	53	2	26	14
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	0	0	0	0
Total revenues		190	88	318	208
Corporate, Non-Segment | Other Operating Segment | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Corporate, Non-Segment | Other Operating Segment | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Corporate, Non-Segment | Other Operating Segment | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Corporate, Non-Segment | Other Operating Segment | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Corporate, Non-Segment | Other Operating Segment | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Corporate, Non-Segment | Other Operating Segment | Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		137	86	292	194
Intersegment Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(478)	(308)	(1,039)	(689)
Revenue Not from Contract with Customer, Other	[1]	(1)	(1)	(2)	(1)
Revenues Adjustments For Certain Risk Management Activities Costs	[2]	152	94	371	227
Total revenues		(327)	(215)	(670)	(463)
Intersegment Eliminations [Member] | Regulated Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(21)	(20)	(41)	(41)
Intersegment Eliminations [Member] | NonRegulated Service Monetary Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(55)	(37)	(100)	(75)
Intersegment Eliminations [Member] | NonRegulated Service Commodity Consideration [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		0	0	0	0
Intersegment Eliminations [Member] | Other Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(5)	(4)	(10)	(9)
Intersegment Eliminations [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		(81)	(61)	(151)	(125)
Intersegment Eliminations [Member] | Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax		$ (397)	$ (247)	$ (888)	$ (564)

[1] Revenues not derived from contracts with customers primarily consist of physical product sales related to commodity derivative contracts, realized and unrealized gains and losses associated with Williams’ commodity derivative contracts, which are reported in Net gain (loss) from commodity derivatives in the Consolidated Statement of Income, management fees received for certain services provided to operated equity-method investments, and leasing revenues associated with the Williams headquarters building.

[2] Other adjustments reflect certain costs of Gas & NGL Marketing Services’ risk management activities. 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 in the Consolidated Statement of Income.

[3] 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.