Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net deferred gains on derivatives-hedging activities, tax	$ (48)	$ 52	$ 195
Changes in unrealized net gains (losses) on investment securities, tax	(7)	(54)	(86)
Changes in net unrecognized pension and other postretirement benefit costs, tax	(147)	(40)	99
Net derivative (gains) losses-hedging activities, tax	(28)	(193)	(336)
Net realized (gains) losses on investment securities, tax	4	(9)	1
Net pension and other postretirement benefit costs, tax	25	38	19
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, before Taxes			20
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes			12
Virginia Electric and Power Company [Member]
Net deferred gains on derivatives-hedging activities, tax	(3)	(1)	4
Change in unrealized net gains (losses) on nuclear decommissioning trust funds, tax	(1)	(6)	(8)
Net derivative (gains) losses-hedging activities, tax	0	(4)	1
Net realized (gains) losses on investment securities, tax	0	(2)	1
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, before Taxes			3
Other Comprehensive Income (Loss), Effect of Change in Accounting Principle, Net of Taxes			$ 2