Significant Financing Transactions Significant Financing Transactions-Preferred Stock (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended				9 Months Ended
	Mar. 31, 2011	Sep. 30, 2014	Sep. 30, 2014 Flex Money Market Preferred 12/02, Series A		Sep. 30, 2014 $5.00		Sep. 30, 2014 $4.04		Sep. 30, 2014 $4.20		Sep. 30, 2014 $4.12		Sep. 30, 2014 $4.80		Sep. 30, 2014 $7.05		Sep. 30, 2014 $6.98
Dividends Payable [Line Items]
Issued and Outstanding Shares		2,590	1,250		107		13		15		32		73		500		600
Redemption Price Per Share			$ 100.00	[1]	$ 112.50	[2]	$ 102.27	[2]	$ 102.50	[2]	$ 103.73	[2]	$ 101.00	[2]	$ 100.00	[2]	$ 100.00	[2]
Dividend					$ 5.00		$ 4.04		$ 4.20		$ 4.12		$ 4.80		$ 7.05		$ 6.98
Dividend rate	6.12%

[1] In February 2014, Virginia Power provided irrevocable notice to redeem the stock. On March 20, 2014, the stock was redeemed at the applicable price per share plus accumulated and unpaid dividends at a rate reset in March 2011 of 6.12%. Dividends ceased accumulating on the stock upon payment of the redemption price, thus the rate was not reset in March 2014.

[2] In September 2014, Virginia Power provided irrevocable notice to redeem all shares outstanding for each series of preferred stock. On October 20, 2014, the stock was redeemed at the applicable price per share plus accumulated and unpaid dividends. Proceeds from Virginia Power's senior notes issued in October 2014 were used to pay the redemption price.