Short-Term Debt And Credit Agreements (Commercial Paper, Bank Loans, and Letters of Credit Outstanding, as well as Capacity Available Under Credit Facilities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011	Dec. 31, 2011		Dec. 31, 2010
Facility Limit	$ 3,500			$ 3,500		$ 3,500
Outstanding Commercial Paper	1,814	[1]		1,814	[1]	1,386	[1]
Outstanding Letters of Credit	36			36		136
Facility Capacity Available	1,650			1,650		1,978
Weighted-average interest rates of the outstanding commercial paper	0.47%			0.47%		0.41%
Credit Facility 1.5 Billion [Member]
Facility Limit	3,000	[2]		3,000	[2]	3,000	[2]
Outstanding Commercial Paper	1,814	[2]		1,814	[2]	1,386	[2]
Outstanding Letters of Credit	0	[2]		0	[2]	101	[2]
Facility Capacity Available	1,186	[2]		1,186	[2]	1,513	[2]
Credit facility initiation date				September 2010
Credit facility termination date	September 2016		September 2013
Three-Year Joint Revolving Credit Facility [Member]
Facility Limit	500	[3]		500	[3]	500	[3]
Outstanding Commercial Paper	0	[3]		0	[3]	0	[3]
Outstanding Letters of Credit	36	[3]		36	[3]	35	[3]
Facility Capacity Available	464	[3]		464	[3]	465	[3]
Credit facility initiation date				September 2010
Credit facility termination date	September 2016		September 2013
Credit facility, to support letters of credit	$ 1,500			$ 1,500

[1] The weighted-average interest rates of the outstanding commercial paper supported by Dominion's credit facilities were 0.47% and 0.41% at December 31, 2011 and 2010, respectively.

[2] This credit facility was entered into in September 2010 with an original maturity date of September 2013. Effective October 1, 2011, pricing was amended and the maturity date was extended to September 2016. This credit facility can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.5 billion of letters of credit.

[3] This credit facility was entered into in September 2010 with an original maturity date of September 2013. Effective October 1, 2011, pricing was amended and the maturity date was extended to September 2016. This credit facility can be used to support bank borrowings, commercial paper and letter of credit issuances.