Earnings Per Share (Calculation of Basic and Diluted EPS) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income attributable to Dominion		$ 452	$ 413	$ 976	$ 949
Average shares of common stock outstanding – Basic (shares)		615.6	591.5	606.1	589.7
Net effect of dilutive securities (shares)	[1]	1.4	1.0	1.5	1.5
Average shares of common stock outstanding – Diluted (shares)		617.0	592.5	607.6	591.2
Earnings Per Common Share – Basic		$ 0.73	$ 0.70	$ 1.61	$ 1.61
Earnings Per Common Share – Diluted		$ 0.73	$ 0.70	$ 1.61	$ 1.60

[1] Dilutive securities consist primarily of the 2013 Equity Units. See Note 14 in this report and Note 17 to the Consolidated Financial Statements in the Companies' Annual Report on Form 10-K for the year ended December 31, 2015 for more information.