Derivatives and Hedge Accounting Activities (Gains and Losses on our Derivatives in Cash Flow Hedging Relationships) (Details) - Cash Flow Hedges - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1]	$ 184	$ 37	$ (404)
Amount of Gain (Loss) Reclassified from AOCI to Income		176	(152)	(130)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]	(9)	(85)	86
Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1]	230	245	(481)
Amount of Gain (Loss) Reclassified from AOCI to Income		187	(136)	(115)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]	4	(4)	5
Commodity | Operating Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI to Income		203	(130)	(58)
Commodity | Purchased gas
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI to Income		(15)	(13)	(47)
Commodity | Electric fuel and other energy-related purchases
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI to Income		(1)	7	(10)
Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1],[3]	(46)	(208)	77
Amount of Gain (Loss) Reclassified from AOCI to Income	[3]	(11)	(16)	(15)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2],[3]	(13)	(81)	81
Virginia Electric and Power Company
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[4]	(3)	(6)	9
Amount of Gain (Loss) Reclassified from AOCI to Income		(1)	5	0
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[5]	(9)	(85)	86
Virginia Electric and Power Company | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[4]	0	4	0
Amount of Gain (Loss) Reclassified from AOCI to Income		(1)	5	0
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[5]	4	(4)	5
Virginia Electric and Power Company | Commodity | Electric Fuel and Other Energy-Related Purchases
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI to Income		(1)	5	0
Virginia Electric and Power Company | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[4],[6]	(3)	(10)	9
Amount of Gain (Loss) Reclassified from AOCI to Income	[6]	0	0	0
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[5],[6]	(13)	(81)	81
Dominion Gas Holdings, LLC
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[7]	10	(50)	66
Amount of Gain (Loss) Reclassified from AOCI to Income		6	(13)	(16)
Dominion Gas Holdings, LLC | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[7]	16	12	(2)
Amount of Gain (Loss) Reclassified from AOCI to Income		6	(12)	(16)
Dominion Gas Holdings, LLC | Commodity | Operating Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI to Income		6	2	(2)
Dominion Gas Holdings, LLC | Commodity | Purchased gas
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI to Income			(14)	(14)
Dominion Gas Holdings, LLC | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[7],[8]	(6)	(62)	68
Amount of Gain (Loss) Reclassified from AOCI to Income	[8]	$ 0	$ (1)	$ 0

[1] Amounts deferred into AOCI have no associated effect in Dominion's Consolidated Statements of Income.

[2] Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion's Consolidated Statements of Income.

[3] Amounts recorded in Dominion's Consolidated Statements of Income are classified in interest and related charges.

[4] Amounts deferred into AOCI have no associated effect in Virginia Power's Consolidated Statements of Income.

[5] Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power's Consolidated Statements of Income.

[6] Amounts recorded in Virginia Power's Consolidated Statements of Income are classified in interest and related charges.

[7] Amounts deferred into AOCI have no associated effect in Dominion Gas' Consolidated Statements of Income.

[8] Amounts recorded in Dominion Gas' Consolidated Statements of Income are classified in interest and related charges.