Earnings Per Share (Calculation of our Basic and Diluted EPS) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net income attributable to Dominion		$ 357	$ 593	$ 413	$ 536	$ 243	$ 529	$ 159	$ 379	$ 1,899	$ 1,310	$ 1,697
Average shares of common stock outstanding-Basic										592.4	582.7	578.7
Net effect of potentially dilutive securities	[1]									1.3	1.8	0.8
Average shares of common stock outstanding-Diluted										593.7	584.5	579.5
Earnings Per Common Share-Basic (in dollars per share)		$ 0.60	$ 1.00	$ 0.70	$ 0.91	$ 0.42	$ 0.91	$ 0.27	$ 0.65	$ 3.21	$ 2.25	$ 2.93
Earnings Per Common Share-Diluted (in dollars per share)		$ 0.60	$ 1.00	$ 0.70	$ 0.91	$ 0.42	$ 0.90	$ 0.27	$ 0.65	$ 3.20	$ 2.24	$ 2.93

[1] Dilutive securities consist primarily of the 2013 Equity Units for 2015, the 2013 Equity Units and contingently convertible senior notes for 2014, and contingently convertible senior notes for 2013. Dominion redeemed all of its contingently convertible senior notes in 2014. See Note 17 for more information.