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, 2015		Dec. 31, 2014
Investment Holdings [Line Items]
Amortized Cost, Total	$ 2,844		$ 2,794
Total Unrealized Gains	1,402	[1]	1,408	[1]
Total Unrealized Losses	(2)	[1],[2]	(6)	[1],[2]
Nuclear decommissioning trust funds	4,244		4,196	[3]
Net assets related to pending sales and purchases of securities	3		3
Fair Value of securities in an unrealized loss position	239		379
Cost method investments
Investment Holdings [Line Items]
Amortized Cost, Other Investments	77		86
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	77		86
Cash Equivalents and Other Investment
Investment Holdings [Line Items]
Amortized Cost, Other Investments	8	[4]	16	[4]
Total Unrealized Gains	0	[1],[4]	0	[1],[4]
Total Unrealized Losses	0	[1],[4]	0	[1],[4]
Nuclear decommissioning trust funds	8	[4]	16	[4]
Equity Securities | U.S. large cap | U.S.:
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	1,265		1,273
Total Unrealized Gains	1,338	[1]	1,353	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	2,603		2,626
Corporate bonds
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	440		424
Total Unrealized Gains	23	[1]	19	[1]
Total Unrealized Losses	(1)	[1]	(2)	[1]
Nuclear decommissioning trust funds	462		441
U.S. Treasury securities and agency debentures
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	576		597
Total Unrealized Gains	17	[1]	13	[1]
Total Unrealized Losses	(1)	[1]	(4)	[1]
Nuclear decommissioning trust funds	592		606
State and municipal
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	356		332
Total Unrealized Gains	24	[1]	23	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	380		355
Other
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	122		66
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	122		66
Virginia Electric and Power Company
Investment Holdings [Line Items]
Amortized Cost, Total	1,331		1,314
Total Unrealized Gains	620	[1]	619	[1]
Total Unrealized Losses	(1)	[1],[5]	(3)	[1],[5]
Nuclear decommissioning trust funds	1,950		1,930	[6]
Net assets related to pending sales and purchases of securities	4		6
Fair Value of securities in an unrealized loss position	120		170
Virginia Electric and Power Company | Cost method investments
Investment Holdings [Line Items]
Amortized Cost, Other Investments	77		86
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	77		86
Virginia Electric and Power Company | Cash Equivalents and Other Investment
Investment Holdings [Line Items]
Amortized Cost, Other Investments	4	[7]	6	[7]
Total Unrealized Gains	0	[1],[7]	0	[1],[7]
Total Unrealized Losses	0	[1],[7]	0	[1],[7]
Nuclear decommissioning trust funds	4	[7]	6	[7]
Virginia Electric and Power Company | Equity Securities | U.S. large cap | U.S.:
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	573		563
Total Unrealized Gains	592	[1]	594	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	1,165		1,157
Virginia Electric and Power Company | Corporate bonds
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	247		242
Total Unrealized Gains	11	[1]	9	[1]
Total Unrealized Losses	0	[1]	(1)	[1]
Nuclear decommissioning trust funds	258		250
Virginia Electric and Power Company | U.S. Treasury securities and agency debentures
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	190		197
Total Unrealized Gains	3	[1]	3	[1]
Total Unrealized Losses	(1)	[1]	(2)	[1]
Nuclear decommissioning trust funds	192		198
Virginia Electric and Power Company | State and municipal
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	209		197
Total Unrealized Gains	14	[1]	13	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	223		210
Virginia Electric and Power Company | Other
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities	31		23
Total Unrealized Gains	0	[1]	0	[1]
Total Unrealized Losses	0	[1]	0	[1]
Nuclear decommissioning trust funds	$ 31		$ 23

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

[2] The fair value of securities in an unrealized loss position was $239 million and $379 million at March 31, 2015 and December 31, 2014, respectively.

[3] Dominion’s Consolidated Balance Sheet at December 31, 2014 has been derived from the audited Consolidated Financial Statements at that date.

[4] Includes pending sales of securities of $3 million at both March 31, 2015 and December 31, 2014.

[5] The fair value of securities in an unrealized loss position was $120 million and $170 million at March 31, 2015 and December 31, 2014, respectively.

[6] Virginia Power’s Consolidated Balance Sheet at December 31, 2014 has been derived from the audited Consolidated Financial Statements at that date.

[7] Includes pending sales of securities of $4 million and $6 million at March 31, 2015 and December 31, 2014, respectively.