Derivatives and Hedge Accounting Activities (Volume of Derivative Activity) (Details) gal in Thousands, MMcf in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) MWh MW gal MMcf
Fixed Price - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	99	[1]
Fixed Price - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	29	[1]
Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	229
Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	591
Fixed Price - Electricity - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	13,212,481
Fixed Price - Electricity - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	1,940,000
Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	14,308,210
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	3,050
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	76,692	[2]
Liquids - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	0	[2]
Interest Rate - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $	$ 2,200
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)	36	[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)	17	[3]
Virginia Electric and Power Company | Basis - Natural Gas - Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	106
Virginia Electric and Power Company | Basis - Natural Gas - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal)	545
Virginia Electric and Power Company | Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh	11,952,866
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	3,050
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 | $	$ 700
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	67,704
Dominion Gas Holdings, LLC | Liquids - Non-current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Volume of derivative activity (bcf, Gal) | gal	0
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.