Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net deferred gains (losses) on derivatives-hedging activities, tax	$ 5	$ 48	$ (52)
Changes in unrealized net gains (losses) on investment securities, tax	(68)	(7)	(54)
Changes in net unrecognized pension and other postretirement benefit costs, tax	209	147	40
Net derivative (gains) losses-hedging activities, tax	34	28	193
Net realized (gains) losses on investment securities, tax	16	(4)	9
Net pension and other postretirement benefit costs, tax	(32)	(25)	(38)
Virginia Electric and Power Company
Net deferred gains (losses) on derivatives-hedging activities, tax	3	3	1
Changes in unrealized net gains (losses) on investment securities, tax	(7)	(1)	(6)
Net derivative (gains) losses-hedging activities, tax	(2)	0	4
Net realized (gains) losses on investment securities, tax	$ 2	$ 0	$ 2