Regulatory Matters - EEGH (Details) - USD ($) $ in Millions		1 Months Ended		3 Months Ended	12 Months Ended
	Aug. 01, 2020	Dec. 31, 2020	Jan. 31, 2020	Oct. 31, 2020	Dec. 31, 2018
Eastern Gas Transmission and Storage, Inc. [Member] | 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
Eastern Gas Transmission and Storage, Inc. [Member] | 2012 FERC Case, Disallowance Of Plant, Resolved In Q4 2018
Schedule Of Regulatory Assets and Liabilities [Line Items]
Litigation settlement expense					$ 129
Litigation settlement expense, after-tax					$ 94
General Rate Case [Member] | Federal Energy Regulatory Commission | Cove Point LNG, LP [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Proposed annual cost-of-service			$ 182
General Rate Case, Increase In Revenue | Federal Energy Regulatory Commission | Cove Point LNG, LP [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Approved rate increase (decrease) amount	$ 4
General Rate Case, Decrease In Depreciation Expense | Federal Energy Regulatory Commission | Cove Point LNG, LP [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Approved rate increase (decrease) amount	$ (1)
General Rate Case, Provision | Federal Energy Regulatory Commission | Cove Point LNG, LP [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Approved rate increase (decrease) amount				$ 7