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	Sep. 30, 2011		Dec. 31, 2010
Available-for-sale Securities, Amortized Cost Basis, and Other Investments	$ 2,361		$ 2,340
Total Unrealized Gains	442	[1]	563	[1]
Total Unrealized Losses	(4)	[1],[2]	(6)	[1],[2]
Fair Value	2,799		2,897	[3]
Net assets related to pending sales and purchases of securities	23		43
Fair Value of securities in an unrealized loss position	158		252
Equity Securities [Member] | Large Cap [Member] | United States [Member]
Amortized Cost	1,147		1,161
Total Unrealized Gains	377	[1]	515	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	1,524		1,676
Equity Securities [Member] | Other Market [Member] | United States [Member]
Amortized Cost	36		39
Total Unrealized Gains	4	[1]	11	[1]
Total Unrealized Losses	0	[1]	0	[1]
Fair Value	40		50
Corporate Debt Securities [Member]
Amortized Cost	294		310
Total Unrealized Gains	18	[1]	18	[1]
Total Unrealized Losses	(2)	[1]	(1)	[1]
Fair Value	310		327
U.S. Treasury Securities and Agency Debentures [Member]
Amortized Cost	460		380
Total Unrealized Gains	24	[1]	12	[1]
Total Unrealized Losses	(1)	[1]	(1)	[1]
Fair Value	483		391
State and Municipal [Member]
Amortized Cost	237		244
Total Unrealized Gains	18	[1]	7	[1]
Total Unrealized Losses	0	[1]	(4)	[1]
Fair Value	255		247
Other Debt Securities [Member]
Amortized Cost	29		19
Total Unrealized Gains	1	[1]	0	[1]
Total Unrealized Losses	(1)	[1]	0	[1]
Fair Value	29		19
Cost-method Investments [Member]
Amortized Cost	113		108
Fair Value	113		108
Cash Equivalents and Other Investment [Member]
Amortized Cost	45	[4]	79	[4]
Fair Value	$ 45	[4]	$ 79	[4]

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

[2] The fair value of securities in an unrealized loss position was $158 million and $252 million at September 30, 2011 and December 31, 2010, respectively.

[3] Dominion’s Consolidated Balance Sheet at December 31, 2010 has been derived from the audited Consolidated Financial Statements at that date.

[4] Includes pending purchases of securities of $23 million and $43 million at September 30, 2011 and December 31, 2010, respectively.