Revenue from Contracts with Customers - EGTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue from External Customer [Line Items]
Operating revenue	$ 7,500	$ 6,968	$ 20,142	$ 19,113
EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	244	209	707	644
Other revenue	(4)	0	(10)	(2)
Operating revenue	240	209	697	642
Regulated
Revenue from External Customer [Line Items]
Total Customer Revenue	5,055	4,430	13,159	12,111
Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	225	195	651	595
Nonregulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	19	14	56	49
Gas transportation | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	151	134	461	422
Gas storage | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	74	47	190	142
Wholesale | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	$ 0	$ 14	$ 0	$ 31