Significant Financing Transactions - (Narrative) (Details) (USD $)	1 Months Ended		3 Months Ended						1 Months Ended
	Mar. 31, 2014	Feb. 28, 2014	Mar. 31, 2014 Convertible Debt	Feb. 28, 2014 Senior Notes Maturing in 2024 Senior Notes	Feb. 28, 2014 Senior Notes Maturing in 2044 Senior Notes	Mar. 31, 2014 Senior Notes Maturing in 2017 Senior Notes	Feb. 28, 2014 Utility Tax Exempt Loan, 2.5%, due 2022 Solid Waste and Sewage Disposal Revenue Bonds	Feb. 28, 2014 Utility Tax Exempt Loan, 2.5%, due 2030 Solid Waste and Sewage Disposal Revenue Bonds	Apr. 30, 2014 Utility Tax Exempt Loan, 2.5%, due 2022 and 2030 Solid Waste and Sewage Disposal Revenue Bonds Subsequent Event	Mar. 31, 2014 Virginia Electric and Power Company	Mar. 31, 2014 Virginia Electric and Power Company Tax Exempt Debt
Debt Instrument [Line Items]
Credit facility										$ 120,000,000
Variable rate tax-exempt financings											119,000,000
Long term debt amount				350,000,000	400,000,000	400,000,000	10,000,000	30,000,000
Annual Interest Rate				3.45%	4.45%	1.25%	2.50%	2.50%
Amount of outstanding principal amount redeemed									40,000,000
Contingent convertible senior notes			40,000,000
Conversion rate, shares of common stock per $1,000 principal amount of senior notes (in shares)			29.9961
Principal amount of senior notes			$ 1,000
Conversion rate, shares of common stock per $1,000 principal amount of senior notes, conversion price			$ 33.34
Issuance of additional shares			600,000
Average trading price principal amount of senior notes (percentage)			120.00%
Minimum consecutive trading days			20 days
Maximum consecutive trading days			30 days
Debt conversion converted instrument amount			3,000,000
Amount of common stock			$ 3,000,000
Amount of outstanding shares		1,250,000
Redemption price per share	$ 100
Dividend rate	6.12%