Fair Value Measurements (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Project	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2014	Sep. 30, 2012	Jun. 30, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge after tax	$ 33
Impairment charge		1,600
Dominion Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge					55
Impairment charge after tax					33
Impairment charge, net of tax				33
Number of development projects canceled			2
Severance costs					14
Severance costs net of tax					8
Kewaunee
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of utilities					2
Elwood
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Ownership percentage							50.00%
Fair Value, Measurements, Nonrecurring | Dominion Gas Holdings, LLC | Other operations and maintenance expense
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge			6			9
Impairment charge, net of tax			4			6
Fair Value, Measurements, Nonrecurring | Kewaunee
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge							378
Long-lived assets impairment charges, net of tax							244
Inventory write-down							33
Inventory write down, net of tax							21
Severance costs							24
Severance costs net of tax							16
Fair Value, Measurements, Nonrecurring | Kewaunee | Other operations and maintenance expense
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment and other charges, net of tax							281
Impairment and other charges							435
Fair Value, Measurements, Nonrecurring | Salem Harbor | Loss from Discontinued Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
After tax charge on disposal of assets								27
Pretax charge on disposal of assets								16
Fair Value, Measurements, Nonrecurring | Brayton Point and Kincaid | Loss from Discontinued Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge		1,600
Impairment and other charges, net of tax		1,000
Fair Value, Measurements, Nonrecurring | Brayton Point and Kincaid | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long lived assets estimated fair value		216
Gas, Transmission and Distribution Equipment | Fair Value, Measurements, Nonrecurring | Other operations and maintenance expense
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge			49
Impairment charge after tax			29
Gas, Transmission and Distribution Equipment | Fair Value, Measurements, Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value	$ 1		1