Derivatives and Hedge Accounting Activities (Volume of our Derivative Activity) (Details) gal in Thousands, MMcf in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) MWh MW MMcf gal
Fixed Price - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	80	[1]
Fixed Price - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	19	[1]
Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	216
Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	554
Fixed Price - Electricity - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	15,661,078
Fixed Price - Electricity - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	0
Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	33,350,993
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	7,600
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	83,076	[2]
Liquids - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	18,606	[2]
Interest Rate - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 2,950
Interest Rate - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 3,100
Virginia Electric and Power Company | Fixed Price - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	32	[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)	10	[3]
Virginia Electric and Power Company | Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	102
Virginia Electric and Power Company | Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	509
Virginia Electric and Power Company | Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	30,383,934
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	7,600
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 | $	$ 900
Virginia Electric and Power Company | Interest Rate - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 1,100
Dominion Gas Holdings, LLC | Liquids - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	77,364
Dominion Gas Holdings, LLC | Liquids - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	13,818
Dominion Gas Holdings, LLC | Interest Rate - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 250
Dominion Gas Holdings, LLC | Interest Rate - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 0

[1] Includes options.

[2] Includes NGLs and oil.

[3] Includes options.