Derivatives and Hedge Accounting Activities (Volume of Derivative Activity) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014
Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate	$ 1,650
Current Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	57,000,000,000	[1]
Current Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	298,000,000,000
Current Derivative Contract | Electricity | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	15,326,454
Current Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	54,017,119
Current Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW)	6,100
Current Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	37,170,000	[2]
Noncurrent Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate	4,400
Noncurrent Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	12,000,000,000	[1]
Noncurrent Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	606,000,000,000
Noncurrent Derivative Contract | Electricity | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	9,127,500
Noncurrent Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	0
Noncurrent Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW)	12,200
Noncurrent Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	0	[2]
Virginia Electric and Power Company | Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate	0
Virginia Electric and Power Company | Current Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	8,000,000,000	[1]
Virginia Electric and Power Company | Current Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	23,000,000,000
Virginia Electric and Power Company | Current Derivative Contract | Electricity | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	50,400
Virginia Electric and Power Company | Current Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	53,863,519
Virginia Electric and Power Company | Current Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW)	6,100
Virginia Electric and Power Company | Noncurrent Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate	850
Virginia Electric and Power Company | Noncurrent Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	0	[1]
Virginia Electric and Power Company | Noncurrent Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	0
Virginia Electric and Power Company | Noncurrent Derivative Contract | Electricity | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	0
Virginia Electric and Power Company | Noncurrent Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh)	0
Virginia Electric and Power Company | Noncurrent Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW)	12,200
Dominion Gas Holdings, LLC | Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate	0
Dominion Gas Holdings, LLC | Current Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	1,000,000,000
Dominion Gas Holdings, LLC | Current Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	1,000,000,000
Dominion Gas Holdings, LLC | Current Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	30,492,000
Dominion Gas Holdings, LLC | Noncurrent Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate	$ 250
Dominion Gas Holdings, LLC | Noncurrent Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	0
Dominion Gas Holdings, LLC | Noncurrent Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	0
Dominion Gas Holdings, LLC | Noncurrent Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	0

[1] Includes options.

[2] ncludes NGLs and oil.