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	Mar. 31, 2013		Dec. 31, 2012
Amortized Cost, Total	$ 2,581		$ 2,511
Total Unrealized Gains	967	[1]	821	[1]
Total Unrealized Losses	(1)	[1],[2]	(2)	[1],[2]
Fair Value	3,547		3,330	[3]
Net assets related to pending sales and purchases of securities	14		6
Fair Value of securities in an unrealized loss position	208		195
Cost method investments
Amortized Cost, Other Investments	113		117
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	113		117
Cash Equivalents and Other Investment
Amortized Cost, Other Investments	63	[4]	72	[4]
Total Unrealized Gains	0	[1],[4]	0	[1],[4]
Total Unrealized Losses	0	[1],[4]	0	[1],[4]
Fair Value	63	[4]	72	[4]
Equity Securities | Large Cap | United States
Amortized Cost, Marketable Securities	1,153		1,210
Total Unrealized Gains	879	[1]	732	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	2,032		1,942
Equity Securities | Other | United States
Amortized Cost, Marketable Securities	44		40
Total Unrealized Gains	18	[1]	13	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	62		53
Corporate bonds
Amortized Cost, Marketable Securities	336		295
Total Unrealized Gains	28	[1]	30	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	364		325
U.S. Treasury securities and agency debentures
Amortized Cost, Marketable Securities	628		523
Total Unrealized Gains	19	[1]	19	[1]
Total Unrealized Losses	(1)	[1]	(2)	[1]
Fair Value	646		540
State and municipal
Amortized Cost, Marketable Securities	236		248
Total Unrealized Gains	23	[1]	26	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	259		274
Other
Amortized Cost, Marketable Securities	8		6
Total Unrealized Gains	0	[1]	1	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	8		7
Virginia Electric and Power Company
Amortized Cost, Total	1,197		1,179
Total Unrealized Gains	412	[1]	337	[1]
Total Unrealized Losses	(1)	[1],[5]	(1)	[1],[5]
Fair Value	1,608		1,515	[6]
Net assets related to pending sales and purchases of securities	2		6
Fair Value of securities in an unrealized loss position	111		104
Virginia Electric and Power Company | Cost method investments
Amortized Cost, Other Investments	113		117
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	113		117
Virginia Electric and Power Company | Cash Equivalents and Other Investment
Amortized Cost, Other Investments	31	[7]	44	[7]
Total Unrealized Gains	0	[1],[7]	0	[1],[7]
Total Unrealized Losses	0	[1],[7]	0	[1],[7]
Fair Value	31	[7]	44	[7]
Virginia Electric and Power Company | Equity Securities | Large Cap | United States
Amortized Cost, Marketable Securities	490		481
Total Unrealized Gains	373	[1]	298	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	863		779
Virginia Electric and Power Company | Equity Securities | Other | United States
Amortized Cost, Marketable Securities	21		20
Total Unrealized Gains	9	[1]	7	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	30		27
Virginia Electric and Power Company | Corporate bonds
Amortized Cost, Marketable Securities	198		179
Total Unrealized Gains	16	[1]	17	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	214		196
Virginia Electric and Power Company | U.S. Treasury securities and agency debentures
Amortized Cost, Marketable Securities	248		231
Total Unrealized Gains	5	[1]	4	[1]
Total Unrealized Losses	(1)	[1]	(1)	[1]
Fair Value	252		234
Virginia Electric and Power Company | State and municipal
Amortized Cost, Marketable Securities	95		106
Total Unrealized Gains	9	[1]	11	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	104		117
Virginia Electric and Power Company | Other
Amortized Cost, Marketable Securities	1		1
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	$ 1		$ 1

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

[2] The fair value of securities in an unrealized loss position was $208 million and $195 million at March 31, 2013 and December 31, 2012, respectively.

[3] Dominion’s Consolidated Balance Sheet at December 31, 2012 has been derived from the audited Consolidated Financial Statements at that date.

[4] Includes pending purchases of securities of $14 million and $6 million at March 31, 2013 and December 31, 2012, respectively.

[5] The fair value of securities in an unrealized loss position was $111 million and $104 million at March 31, 2013 and December 31, 2012, respectively.

[6] Virginia Power’s Consolidated Balance Sheet at December 31, 2012 has been derived from the audited Consolidated Financial Statements at that date.

[7] Includes pending sales of securities of $2 million and $6 million at March 31, 2013 and December 31, 2012, respectively.