Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Net deferred gains (losses) on derivative-hedging activities, tax	$ (80)	$ 58
Changes in unrealized net gains (losses) on investment securities, tax	(56)	(25)
Changes in net unrecognized pension and other postretirement benefit costs, tax	0	(15)
Net derivative (gains) losses-hedging activities, tax	12	(5)
Net realized gains on investment securities, tax	6	2
Net pension and other postretirement benefit costs, tax	(9)	(2)
Virginia Electric and Power Company [Member]
Net deferred gains (losses) on derivative-hedging activities, tax	0	0
Changes in unrealized net gains (losses) on investment securities, tax	(5)	(2)
Net derivative (gains) losses-hedging activities, tax	(1)	0
Net realized gains on investment securities, tax	$ 1	$ 0