Derivatives and Hedge Accounting Activities (Volume of Derivative Activity) (Details) gal in Thousands, MMcf in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($) MWh MW gal MMcf
Fixed Price - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	57	[1]
Fixed Price - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	14	[1]
Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	267
Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	605
Fixed Price - Electricity - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	13,869,299
Fixed Price - Electricity - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	3,399,889
Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	49,967,941
Financial Transmission Rights - Electricity- Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	0
Capacity - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of capacity (MW) | MW	12,200
Capacity - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of capacity (MW) | MW	0
Liquids - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	65,772	[2]
Liquids - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	18,774	[2]
Interest Rate - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 2,250
Interest Rate - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 3,000
Virginia Electric and Power Company | Fixed Price - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	12	[3]
Virginia Electric and Power Company | Fixed Price - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	0	[3]
Virginia Electric and Power Company | Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	130
Virginia Electric and Power Company | Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	539
Virginia Electric and Power Company | Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	49,069,990
Virginia Electric and Power Company | Financial Transmission Rights - Electricity- Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	0
Virginia Electric and Power Company | Capacity - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of capacity (MW) | MW	12,200
Virginia Electric and Power Company | Capacity - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of capacity (MW) | MW	0
Virginia Electric and Power Company | Interest Rate - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 450
Virginia Electric and Power Company | Interest Rate - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 750
Dominion Gas Holdings, LLC | Fixed Price - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	3
Dominion Gas Holdings, LLC | Fixed Price - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	0
Dominion Gas Holdings, LLC | Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	3
Dominion Gas Holdings, LLC | Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	0
Dominion Gas Holdings, LLC | Liquids - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	64,302
Dominion Gas Holdings, LLC | Liquids - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	16,758
Dominion Gas Holdings, LLC | Interest Rate - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 0
Dominion Gas Holdings, LLC | Interest Rate - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 250

[1] Includes options.

[2] Includes NGLs and oil.

[3] Includes options.