Acquisitions and Dispositions (Schedule of Capital Expenditures and Significant Noncash Items Reported As Discontinued Operations) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Significant noncash items
Accrued capital expenditures	[1],[2]	$ 343	$ 201
Dominion Energy Gas Holdings, LLC
Significant noncash items
Accrued capital expenditures		$ 13	31
East Ohio | Dominion Energy Gas Holdings, LLC
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Capital expenditures			65
Significant noncash items
Accrued capital expenditures			6
DGP | Dominion Energy Gas Holdings, LLC
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Capital expenditures			$ 3

[1] See Note 16 for noncash financing activities related to the acquisition of the public interest in Dominion Energy Midstream.

[2] See Note 3 for noncash investing and financing activities related to the SCANA Combination.