Fair Value Measurements (Fair Value, Option, Quantitative Disclosures) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 719		$ 890
Derivative liabilities	794		1,102
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	125
Derivative liabilities	18
Level 3 | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	74	[1]
Derivative liabilities	12	[1]
Level 3 | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	5
Derivative liabilities	2
Level 3 | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	44
Derivative liabilities	4
Level 3 | Liquids | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	2	[2]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Minimum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(2)	[3]
Credit spread	1.00%	[4]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Minimum | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	2	[3]
Price Volatility	19.00%	[5]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Minimum | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(1)	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Minimum | Liquids | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	0	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Weighted Average | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(1)	[3],[6]
Credit spread	2.00%	[4],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Weighted Average | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	3	[3],[6]
Price Volatility	33.00%	[5],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Weighted Average | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	3	[3],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Weighted Average | Liquids | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	1	[3],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Maximum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	11	[3]
Credit spread	5.00%	[4]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Maximum | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	4	[3]
Price Volatility	67.00%	[5]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Maximum | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	21	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Maximum | Liquids | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	2	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Minimum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(2)	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Minimum | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	2	[3]
Price Volatility	19.00%	[5]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Minimum | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(21)	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Weighted Average | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	2	[3],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Weighted Average | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	3	[3],[6]
Price Volatility	33.00%	[5],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Weighted Average | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	0	[3],[6]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Maximum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	4	[3]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Maximum | Gas | Physical and Financial Options:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	4	[3]
Price Volatility	67.00%	[5]
Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Maximum | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	21	[3]
Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	113		53
Derivative liabilities	87		12
Virginia Electric and Power Company | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	106
Derivative liabilities	4
Virginia Electric and Power Company | Level 3 | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	62	[1]
Virginia Electric and Power Company | Level 3 | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	44
Derivative liabilities	$ 4
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Minimum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(2)	[2]
Credit spread	1.00%	[3]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Minimum | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(1)	[2]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Weighted Average | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(1)	[3],[6]
Credit spread	2.00%	[4],[6]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Weighted Average | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	3	[3],[6]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Maximum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	7	[2]
Credit spread	5.00%	[3]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Assets | Maximum | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	21	[2]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Minimum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	(21)	[2]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Weighted Average | FTRs | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	0	[3],[6]
Virginia Electric and Power Company | Level 3 | Fair Value, Option, Quantitative Disclosures, Liabilities | Maximum | Gas | Physical and Financial Forwards and Futures:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Market Price	21	[2]

[1] Includes basis.

[2] Information represents Dominion Gas quantitative information about Level 3 fair value measurements.

[3] Represents market prices beyond defined terms for Levels 1 and 2.

[4] Represents credit spreads unrepresented in published markets.

[5] Represents volatilities unrepresented in published markets.

[6] Averages weighted by volume.