Revenue from Contracts with Customers - EGTS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from External Customer [Line Items]
Operating revenue	$ 6,229	$ 6,612	$ 12,575	$ 12,642
EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	234	233	511	463
Other revenue	2	1	3	(6)
Operating revenue	236	234	514	457
Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	219	214	479	426
Nonregulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	15	19	32	37
Gas transmission | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	151	145	342	310
Gas storage | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	70	69	137	116
Other | Regulated
Revenue from External Customer [Line Items]
Total Customer Revenue	23	28	57	50
Other | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	$ (2)	$ 0	$ 0	$ 0