Investments (Marketable Equity and Debt Securities and Cash Equivalents (Classified as Available-for-sale) and Cost Method Investments in Decommissioning Trust Funds) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Amortized Cost, Total	$ 2,474		$ 2,390
Total Unrealized Gains	849	[1]	611	[1]
Total Unrealized Losses	(1)	[1],[2]	(2)	[1],[2]
Fair Value	3,322		2,999	[3]
Net assets related to pending sales and purchases of securities	6		11
Fair Value of securities in an unrealized loss position	100		164
Cost-method Investments
Amortized Cost, Other Investments	123		118
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	123		118
Cash Equivalents and Other Investment
Amortized Cost, Other Investments	80	[4]	46	[4]
Total Unrealized Gains	0	[1],[4]	0	[4]
Total Unrealized Losses	0	[1],[4]	0	[4]
Fair Value	80	[4]	46	[4]
Equity Securities | Large Cap | United States
Amortized Cost, Marketable Securities	1,182		1,152
Total Unrealized Gains	755	[1]	537	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	1,937		1,689
Equity Securities | Other Market | United States
Amortized Cost, Marketable Securities	40		36
Total Unrealized Gains	12	[1]	10	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	52		46
Corporate bonds
Amortized Cost, Marketable Securities	289		314
Total Unrealized Gains	29	[1]	19	[1]
Total Unrealized Losses	0	[1]	(1)	[1]
Fair Value	318		332
U.S. Treasury Securities and Agency Debentures
Amortized Cost, Marketable Securities	463		437
Total Unrealized Gains	22	[1]	20	[1]
Total Unrealized Losses	(1)	[1]	(1)	[1]
Fair Value	484		456
State and Municipal
Amortized Cost, Marketable Securities	287		264
Total Unrealized Gains	30	[1]	24	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	317		288
Other Debt Securities
Amortized Cost, Marketable Securities	10		23
Total Unrealized Gains	1	[1]	1	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	11		24
Virginia Electric and Power Company
Amortized Cost, Total	1,158		1,123
Total Unrealized Gains	349	[1]	249	[1]
Total Unrealized Losses	(1)	[1],[5]	(2)	[1],[5]
Fair Value	1,506		1,370	[6]
Net assets related to pending sales and purchases of securities	6		13
Fair Value of securities in an unrealized loss position	53		99
Virginia Electric and Power Company | Cost-method Investments
Amortized Cost, Other Investments	123		118
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	123		118
Virginia Electric and Power Company | Cash Equivalents and Other Investment
Amortized Cost, Other Investments	36	[7]	27	[7]
Total Unrealized Gains	0	[1],[7]	0	[1],[7]
Total Unrealized Losses	0	[1],[7]	0	[1],[7]
Fair Value	36	[7]	27	[7]
Virginia Electric and Power Company | Equity Securities | Large Cap | United States
Amortized Cost, Marketable Securities	467		460
Total Unrealized Gains	307	[1]	218	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	774		678
Virginia Electric and Power Company | Equity Securities | Other Market | United States
Amortized Cost, Marketable Securities	20		18
Total Unrealized Gains	6	[1]	5	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	26		23
Virginia Electric and Power Company | Corporate bonds
Amortized Cost, Marketable Securities	177		204
Total Unrealized Gains	17	[1]	11	[1]
Total Unrealized Losses	0	[1]	(1)	[1]
Fair Value	194		214
Virginia Electric and Power Company | U.S. Treasury Securities and Agency Debentures
Amortized Cost, Marketable Securities	197		166
Total Unrealized Gains	6	[1]	4	[1]
Total Unrealized Losses	(1)	[1]	0	[1]
Fair Value	202		170
Virginia Electric and Power Company | State and Municipal
Amortized Cost, Marketable Securities	131		114
Total Unrealized Gains	13	[1]	10	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	144		124
Virginia Electric and Power Company | Other Debt Securities
Amortized Cost, Marketable Securities	7		16
Total Unrealized Gains	0	[1]	1	[1]
Total Unrealized Losses	0	[1]	(1)	[1]
Fair Value	$ 7		$ 16

[1] Included in AOCI and the decommissioning trust regulatory liability.

[2] The fair value of securities in an unrealized loss position was $100 million and $164 million at September 30, 2012 and December 31, 2011, respectively.

[3] Dominion’s Consolidated Balance Sheet at December 31, 2011 has been derived from the audited Consolidated Financial Statements at that date.

[4] Includes pending sales of securities of $6 million and pending purchases of securities of $11 million at September 30, 2012 and December 31, 2011, respectively.

[5] The fair value of securities in an unrealized loss position was $53 million and $99 million at September 30, 2012 and December 31, 2011, respectively.

[6] Virginia Power’s Consolidated Balance Sheet at December 31, 2011 has been derived from the audited Consolidated Financial Statements at that date.

[7] Includes pending sales of securities of $6 million and pending purchases of securities of $13 million at September 30, 2012 and December 31, 2011, respectively.