Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Customer receivables, allowance for doubtful accounts	$ 29	$ 29
Other receivables, allowance for doubtful accounts	5	8
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares outstanding	571,000,000	570,000,000
Virginia Electric and Power Company [Member]
Customer receivables, allowance for doubtful accounts	11	11
Other receivables, allowance for doubtful accounts	$ 4	$ 7
Common stock, shares authorized	500,000	500,000
Common stock, shares outstanding	274,723	274,723