Investments (Recorded Other-Than-Temporary Impairment Losses on Investments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Total other-than-temporary impairment losses	[1]	$ 66	$ 21	$ 31
Losses recorded to nuclear decommissioning trust regulatory liability		(26)	(5)	(13)
Losses recognized in other comprehensive income (before taxes)		(9)	(3)	(10)
Net impairment losses recognized in earnings		31	13	8
Other-than-temporary impairment losses for debt securities		9	3	18
Virginia Electric and Power Company
Schedule of Available-for-sale Securities [Line Items]
Total other-than-temporary impairment losses	[2]	36	8	15
Losses recorded to nuclear decommissioning trust regulatory liability		(26)	(4)	(13)
Losses recognized in other comprehensive income (before taxes)		(6)	(2)	(1)
Net impairment losses recognized in earnings		4	2	1
Other-than-temporary impairment losses for debt securities		$ 6	$ 2	$ 9

[1] Amounts include other-than-temporary impairment losses for debt securities of $9 million, $3 million and $18 million at December 31, 2015, 2014 and 2013, respectively.

[2] Comprised of Dominion Midstream's interest of 25.93% and Dominion Gas' interest of 24.72%. See Note 15 for more information.