Equity (Schedule of Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		$ (416)	$ (324)
Other comprehensive income before reclassifications: gains (losses)		49	(164)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[1]	(107)	72
Other comprehensive income (loss)		(58)	(92)	$ 553
Ending balance		(474)	(416)	(324)
Deferred gains and losses on derivatives-hedging activities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(178)	(288)
Other comprehensive income before reclassifications: gains (losses)		110	17
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[1]	(108)	93
Other comprehensive income (loss)		2	110
Ending balance		(176)	(178)	(288)
Unrealized gains and losses on investment securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		548	474
Other comprehensive income before reclassifications: gains (losses)		6	128
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[1]	(50)	(54)
Other comprehensive income (loss)		(44)	74
Ending balance		504	548	474
Unrecognized pension and other postretirement benefit costs
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(782)	(510)
Other comprehensive income before reclassifications: gains (losses)		(66)	(305)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[1]	51	33
Other comprehensive income (loss)		(15)	(272)
Ending balance		(797)	(782)	(510)
Other comprehensive loss from equity method investees
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(4)	0
Other comprehensive income before reclassifications: gains (losses)		(1)	(4)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[1]	0	0
Other comprehensive income (loss)		(1)	(4)
Ending balance		(5)	(4)	0
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		50	48
Other comprehensive income before reclassifications: gains (losses)		(5)	11
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[2]	(5)	(9)
Other comprehensive income (loss)		(10)	2	23
Ending balance		40	50	48
Virginia Electric and Power Company | Deferred gains and losses on derivatives-hedging activities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(7)	0
Other comprehensive income before reclassifications: gains (losses)		(1)	(4)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[2]	1	(3)
Other comprehensive income (loss)		0	(7)
Ending balance		(7)	(7)	0
Virginia Electric and Power Company | Unrealized gains and losses on investment securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		57	48
Other comprehensive income before reclassifications: gains (losses)		(4)	15
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[2]	(6)	(6)
Other comprehensive income (loss)		(10)	9
Ending balance		47	57	48
Dominion Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(86)	(58)
Other comprehensive income before reclassifications: gains (losses)		(14)	(41)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[3]	1	13
Other comprehensive income (loss)		(13)	(28)	82
Ending balance		(99)	(86)	(58)
Dominion Gas Holdings, LLC | Deferred gains and losses on derivatives-hedging activities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(20)	3
Other comprehensive income before reclassifications: gains (losses)		6	(31)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[3]	(3)	8
Other comprehensive income (loss)		3	(23)
Ending balance		(17)	(20)	3
Dominion Gas Holdings, LLC | Unrealized gains and losses on investment securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(66)	(61)
Other comprehensive income before reclassifications: gains (losses)		(20)	(10)
Amounts reclassified from accumulated other comprehensive income: (gains) losses	[3]	4	5
Other comprehensive income (loss)		(16)	(5)
Ending balance		$ (82)	$ (66)	$ (61)

[1] See table below for details about these reclassifications.

[2] See table below for details about these reclassifications.

[3] See table below for details about these reclassifications.