Revenue from Contracts with Customers - EGTS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue from External Customer [Line Items]
Operating revenue	$ 6,111	$ 6,346
EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	270	277
Other revenue	0	1
Operating revenue	270	278
Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	258	260
Nonregulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	12	17
Gas transmission | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	188	191
Gas storage | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	70	67
Other customer revenue | Regulated
Revenue from External Customer [Line Items]
Total Customer Revenue	27	34
Other customer revenue | Regulated | EGTS
Revenue from External Customer [Line Items]
Total Customer Revenue	$ 0	$ 2