Quarterly Financial and Common Stock Data (Unaudited) (Quarterly Financial and Common Stock Data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Operating Revenue	$ 3,086	$ 3,132	$ 2,598	$ 2,921	$ 2,556	$ 2,971	$ 2,747	$ 3,409	$ 11,737		$ 11,683		$ 12,436
Income from operations	819	1,145	781	882	638	1,123	773	1,002	3,627		3,536		2,721
Net income including noncontrolling interests	491	728	462	531	366	599	418	540	2,212		1,923		1,326
Net income (loss) attributable to Dominion	$ 457	$ 690	$ 452	$ 524	$ 357	$ 593	$ 413	$ 536	$ 2,123		$ 1,899		$ 1,310
Net income attributable to Dominion- Basic (in dollars per share)	$ 0.73	$ 1.10	$ 0.73	$ 0.88	$ 0.60	$ 1.00	$ 0.70	$ 0.91	$ 3.44		$ 3.21		$ 2.25
Net income attributable to Dominion - Diluted (in dollars per share)	0.73	1.10	0.73	0.88	0.60	1.00	0.70	0.91	3.44		3.20		2.24
Dividends declared per common share	$ 0.7	$ 0.7	$ 0.7	$ 0.70	$ 0.6475	$ 0.6475	$ 0.6475	$ 0.6475	$ 2.80		$ 2.59		$ 2.40
Virginia Electric and Power Company
Condensed Financial Statements, Captions [Line Items]
Operating Revenue	$ 1,711	$ 2,211	$ 1,776	$ 1,890	$ 1,614	$ 2,058	$ 1,813	$ 2,137	$ 7,588	[1]	$ 7,622	[1]	$ 7,579	[1]
Income from operations	369	914	553	514	374	741	481	525	2,350		2,121		1,724
Net income (loss) attributable to Dominion	172	503	280	263	187	385	246	269	1,218		1,087		858
Dominion Gas Holdings, LLC
Condensed Financial Statements, Captions [Line Items]
Operating Revenue	457	382	368	431	425	365	395	531	1,638	[2]	1,716	[2]	1,898	[2]
Income from operations	175	133	186	175	163	202	153	271	669		789		851
Net income (loss) attributable to Dominion	$ 106	$ 83	$ 105	$ 98	$ 100	$ 111	$ 85	$ 161	$ 392		$ 457		$ 512
Maximum
Condensed Financial Statements, Captions [Line Items]
Share Price (in dollars per share)	$ 77.32	$ 78.97	$ 77.93	$ 75.18	$ 74.88	$ 76.59	$ 74.34	$ 79.89	$ 77.32		$ 74.88
Common stock market value (high) (in dollars per share)									78.97		79.89
Minimum
Condensed Financial Statements, Captions [Line Items]
Share Price (in dollars per share)	$ 69.51	$ 72.49	$ 68.71	$ 66.25	$ 64.54	$ 66.65	$ 66.52	$ 68.25	69.51		64.54
Common stock market value (low) (in dollars per share)									$ 66.25		$ 64.54

[1] See Note 24 for amounts attributable to affiliates.

[2] See Note 24 for amounts attributable to related parties.