Revenue from Contracts with Customers - EGTS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenue from External Customer [Line Items]
Operating revenue	$ 6,346	$ 6,030
EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	277	230
Other revenue	1	(7)
Operating revenue	278	223
Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	260	212
Nonregulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	17	18
Gas transmission | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	191	165
Gas storage | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	67	47
Other | Regulated
Revenue from External Customer [Line Items]
Total Customer Revenue	34	22
Other | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	$ 2	$ 0