Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net deferred gains (losses) on derivative-hedging activities, tax	$ 35	$ (10)	$ (3)
Changes in unrealized net gains (losses) on investment securities, tax	(14)	5	(121)
Changes in net unrecognized pension and other postretirement benefit costs, tax	(4)	75	32
Net derivative (gains) losses-hedging activities, tax	21	(35)	18
Net realized (gains) losses on investment securities, tax	1	(2)	21
Net pension and other postretirement benefit costs, tax	(23)	(21)	(32)
Changes in other comprehensive income (loss) from equity method investees, tax		(1)	(2)
Virginia Electric and Power Company
Net deferred gains (losses) on derivative-hedging activities, tax	8	(1)	3
Changes in unrealized net gains (losses) on investment securities, tax	(2)		(16)
Net realized (gains) losses on investment securities, tax	1		3
Dominion Energy Gas Holdings, LLC
Net deferred gains (losses) on derivative-hedging activities, tax	22	5	(3)
Changes in net unrecognized pension and other postretirement benefit costs, tax	(13)	20	(8)
Net derivative (gains) losses-hedging activities, tax	(2)	(7)	2
Net pension and other postretirement benefit costs, tax	$ (2)	$ (2)	$ (2)