Derivatives and Hedge Accounting Activities (Volume of Derivative Activity) (Details) - Jun. 30, 2015 gal in Thousands, MMcf in Thousands, $ in Millions		USD ($) MWh MW MMcf gal
Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $		$ 2,050
Current Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	[1]	50
Current Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)		217
Current Derivative Contract | Electricity | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh		12,920,765
Current Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh		69,152,521
Current Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW) | MW		16,800
Current Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons) | gal	[2]	77,616
Noncurrent Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $		$ 3,450
Noncurrent Derivative Contract | Natural Gas | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)	[1]	13
Noncurrent Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)		570
Noncurrent Derivative Contract | Electricity | Fixed Price
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh		5,146,901
Noncurrent Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh		0
Noncurrent Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW) | MW		0
Noncurrent Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons) | gal	[2]	14,616
Virginia Electric and Power Company | Current Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $		$ 450
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)	[3]	11
Virginia Electric and Power Company | Current Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)		92
Virginia Electric and Power Company | Current Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh		67,712,636
Virginia Electric and Power Company | Current Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW) | MW		16,800
Virginia Electric and Power Company | Noncurrent Derivative Contract
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate | $		$ 750
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)	[3]	0
Virginia Electric and Power Company | Noncurrent Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)		515
Virginia Electric and Power Company | Noncurrent Derivative Contract | Electricity | Financial Transmission Rights
Derivative Instruments, Gain (Loss) [Line Items]
Volume of electricity (MWh) | MWh		0
Virginia Electric and Power Company | Noncurrent Derivative Contract | Capacity
Derivative Instruments, Gain (Loss) [Line Items]
Capacity (MW) | MW		0
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)		4
Dominion Gas Holdings, LLC | Current Derivative Contract | Natural Gas | Basis
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons)		4
Dominion Gas Holdings, LLC | Current Derivative Contract | Liquids
Derivative Instruments, Gain (Loss) [Line Items]
Volume of natural gas (cf)/ liquids (gallons) | gal		74,760
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) | gal		12,600

[1] Includes options.

[2] Includes NGLs and oil.

[3] Includes options.