Acquisitions and Dispositions (Schedule of Capital Expenditures and Significant Noncash Items Reported As Discontinued Operations) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Significant noncash items
Charges related to a voluntary retirement program						$ 320
Depreciation, depletion and amortization		$ 2,478		$ 2,332		2,283
Accrued capital expenditures	[1],[2],[3],[4],[5]	637		485		555
Dominion Energy Gas Holdings, LLC | Q-Pipe Group
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Capital expenditures		$ 34	[6]	38		42
Significant noncash items
Impairment of assets and other charges						1
Charges related to a voluntary retirement program						3
Depreciation, depletion and amortization				27		51
Accrued capital expenditures				1		2
Dominion Energy Gas Holdings, LLC | GT&S Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Capital expenditures				292	[6]	386
Significant noncash items
Impairment of assets and other charges				469	[6]	13
Charges related to a voluntary retirement program						19
Depreciation, depletion and amortization				$ 177	[6]	322
Accrued capital expenditures						$ 25

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

[2] See Note 5 for noncash activities related to the sale of a noncontrolling interest in Cove Point.

[3] See Note 9 for noncash investing activities related to the acquisition of a noncontrolling interest in Wrangler.

[4] See Notes 18,19 and 20 for noncash financing activities related to the acquisition of the public interest in Dominion Energy Midstream, the remarketing of RSNs, the issuance of stock purchase contracts associated with the 2019 Equity Units, the contribution of stock to Dominion Energy’s qualified defined benefit pension plan, derivative restructuring and the issuance of common stock associated with the settlement of litigation. See Note 23 for non-cash investing activities related to property, plant and equipment conveyed to satisfy litigation.

[5] See the New Accounting Standards section below for noncash investing and financing activities related to the adoption of a new accounting standard for leasing arrangements.

[6] Operations associated with the Q-Pipe Group are through the December 31, 2021 closing date. Operations associated with the GT&S Transaction are through the November 1, 2020 closing date.