Preferred Stock (Schedule of Equity Units) (Detail) - USD ($) shares in Millions, $ in Millions			1 Months Ended		12 Months Ended
		Jun. 14, 2019	Dec. 31, 2019	Aug. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Capital Unit [Line Items]
Units Issued				18.5	6.1
Total Net Proceeds			$ 2,100
Total Preferred Stock			2,387		$ 2,387	$ 0
Stock Purchase Contract Liability			$ 212		$ 212
Preferred Stock
Capital Unit [Line Items]
Units Issued					2.0
Preferred Stock | 2019 Corporate Units
Capital Unit [Line Items]
Units Issued		16.0
Total Net Proceeds	[1]	$ 1,582
Total Preferred Stock	[2]	$ 1,610
Cumulative Dividend Rate		1.75%
Stock Purchase Contract Annual Rate		5.50%
Stock Purchase Contract Liability	[3]	$ 250

[1] Issuance costs of $28 million were recorded as a reduction to preferred stock ($14 million) and common stock ($14 million) in the Consolidated Balance Sheets.

[2] Dominion Energy recorded dividends of $15 million ($9.479 per share) for the year ended December 31, 2019.

[3] Payments of $38 million were made in 2019. The stock purchase contract liability was $212 million at December 31, 2019.