Regulatory Matters - EGTS - Other Regulatory Matters (Details) - EGTS - USD ($) $ in Millions	1 Months Ended			3 Months Ended	8 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2020	Jun. 30, 2021	Dec. 31, 2022	Feb. 28, 2023
Schedule Of Regulatory Assets and Liabilities [Line Items]
Provision for rate refunds					$ 91	$ 91
FERC Case, Disallowance Of Capitalized AFUDC, Resolved In December 2020
Schedule Of Regulatory Assets and Liabilities [Line Items]
Litigation settlement, expense			$ 43
Litigation settlement, expense, after-tax			$ 31
Litigation settlement, reduction in expense				$ 11
Litigation settlement, reduction in expense, after tax				$ 8
General Rate Case | FERC
Schedule Of Regulatory Assets and Liabilities [Line Items]
Requested rate increase (decrease)		$ 1,100
General Rate Case | FERC | Natural Gas, Storage
Schedule Of Regulatory Assets and Liabilities [Line Items]
Requested rate increase (decrease), percentage		85.00%
General Rate Case | FERC | Natural Gas, General System Transmission
Schedule Of Regulatory Assets and Liabilities [Line Items]
Requested rate increase (decrease), percentage		60.00%
General Rate Case, Transportation and Storage Revenues | FERC
Schedule Of Regulatory Assets and Liabilities [Line Items]
Approved rate increase (decrease)	$ 160				160
General Rate Case, Depreciation Expense | FERC
Schedule Of Regulatory Assets and Liabilities [Line Items]
Approved rate increase (decrease)	$ (30)				$ (30)