Significant Accounting Policies - Schedule of Increase (Decrease) to Each Affected Line Item in Companies' Consolidated Financial Statements (Parenthetical) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in net income from continuing operations	$ 59	$ (15)	$ (12)	$ (13)
increase (decrease) in earnings per share	$ 0.07	$ (0.02)	$ (0.01)	$ (0.02)
Increase in earnings per share from discontinued operations		$ 0.02
Indirect Impacts
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in net income from continuing operations	$ (4)	$ (4)	$ (3)	$ (3)
Decrease in income attributable to noncontrolling interests					$ (6)
Maximum | Indirect Impacts
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
increase (decrease) in earnings per share	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Virginia Power
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase (decrease) in net income	$ 3	$ 2	$ 2	$ 2