Regulatory Matters (Other Regulatory Matters Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Feb. 28, 2021
Public Utilities, General Disclosures [Line Items]
Equity in losses of unconsolidated affiliates		$ (28)	$ 2,005	$ (162)
Other current liabilities		2,471	2,936
Asset retirement obligations		$ 647	$ 718
Atlantic Coast Pipeline (ACP)
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage		47.00%
Atlantic Coast Pipeline (ACP) | Atlantic Coast Pipeline (ACP)
Public Utilities, General Disclosures [Line Items]
Equity in losses of unconsolidated affiliates	$ 2,100
Other current liabilities		$ 47
Other liabilities, noncurrent		53
Atlantic Coast Pipeline (ACP) | Atlantic Coast Pipeline (ACP) | Current Liabilities
Public Utilities, General Disclosures [Line Items]
Guarantor obligations settled					$ 855
Asset retirement obligations		$ 100