Short-Term Debt And Credit Agreements (Commercial Paper, Bank Loans, and Letters of Credit Outstanding, as well as Capacity Available Under Credit Facilities (Details)		1 Months Ended
		Jan. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Facility		Dec. 31, 2014 USD ($)
Short term Debt [Line Items]
Facility Limit	[1]		$ 4,500,000,000		$ 4,500,000,000
Outstanding Commercial Paper	[2]		3,509,000,000		2,775,000,000
Outstanding Letters of Credit			59,000,000		48,000,000
Facility Capacity Available			$ 932,000,000		1,677,000,000
Weighted-average interest rates	[3],[4]		2.38%
Virginia Electric and Power Company
Short term Debt [Line Items]
Facility Limit	[5]		$ 4,500,000,000		4,500,000,000
Outstanding Commercial Paper	[6]		1,656,000,000		1,361,000,000
Outstanding Letters of Credit			$ 0		0
Weighted-average interest rates	[4]		5.24%
Number of joint revolving credit facilities | Facility			2
Credit facility			$ 120,000,000
Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Facility Limit	[7]		1,500,000,000		1,500,000,000
Outstanding Commercial Paper			391,000,000	[8]	0
Outstanding Letters of Credit			$ 0		0
Weighted-average interest rates	[4]		1.05%
Number of joint revolving credit facilities | Facility			2
Line of Credit | Virginia Electric and Power Company
Short term Debt [Line Items]
Credit facility, to support letters of credit			$ 120,000,000
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Virginia Electric and Power Company
Short term Debt [Line Items]
Credit facility, to support letters of credit			1,750,000,000.00
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Facility Limit					$ 1,500,000,000.0
Credit facility, to support letters of credit			500,000,000
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Letter of Credit
Short term Debt [Line Items]
Credit facility, to support letters of credit			2,000,000,000.0
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Letter of Credit | Virginia Electric and Power Company
Short term Debt [Line Items]
Facility Limit			2,000,000,000.0
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Letter of Credit | Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Facility Limit			1,500,000,000.0
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Line of Credit
Short term Debt [Line Items]
Facility Limit			4,000,000,000
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Line of Credit | Virginia Electric and Power Company
Short term Debt [Line Items]
Facility Limit			$ 4,000,000,000
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Commercial Paper
Short term Debt [Line Items]
Weighted-average interest rates			0.62%		0.38%
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Commercial Paper | Virginia Electric and Power Company
Short term Debt [Line Items]
Weighted-average interest rates			0.60%		0.36%
Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Commercial Paper | Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Weighted-average interest rates			0.63%
Credit Facility 4 Billion
Short term Debt [Line Items]
Facility Limit	[1]		$ 4,000,000,000	[9]	$ 4,000,000,000
Outstanding Commercial Paper	[1]		3,353,000,000	[9]	2,664,000,000
Outstanding Letters of Credit	[1]		0	[9]	0
Facility Capacity Available	[1]		647,000,000	[9]	1,336,000,000
Credit Facility 4 Billion | Virginia Electric and Power Company
Short term Debt [Line Items]
Facility Limit	[5]		4,000,000,000	[10]	4,000,000,000
Outstanding Commercial Paper	[5]		1,500,000,000	[10]	1,250,000,000
Outstanding Letters of Credit	[5]		0	[10]	0
Credit Facility 4 Billion | Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Facility Limit	[7]		1,000,000,000		1,000,000,000
Outstanding Commercial Paper	[7]		391,000,000		0
Outstanding Letters of Credit	[7]		0		0
Credit Facility 500 million
Short term Debt [Line Items]
Facility Limit	[1]		500,000,000		500,000,000
Outstanding Commercial Paper	[1]		156,000,000		111,000,000
Outstanding Letters of Credit	[1]		59,000,000		48,000,000
Facility Capacity Available	[1]		285,000,000		341,000,000
Credit Facility 500 million | Virginia Electric and Power Company
Short term Debt [Line Items]
Facility Limit	[5]		500,000,000		500,000,000
Outstanding Commercial Paper	[5]		156,000,000		111,000,000
Outstanding Letters of Credit	[5]		0		0
Credit Facility 500 million | Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Facility Limit	[7]		500,000,000		500,000,000
Outstanding Commercial Paper	[7]		0		0
Outstanding Letters of Credit	[7]		0		$ 0
Tax-Exempt Financings | Virginia Electric and Power Company
Short term Debt [Line Items]
Variable rate tax-exempt financings			$ 119,000,000
Subsequent Event | Revolving Credit Facility
Short term Debt [Line Items]
Increase in revolving credit facility limits		$ 1,000,000,000
Subsequent Event | Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Line of Credit
Short term Debt [Line Items]
Facility Limit		5,000,000,000
Subsequent Event | Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Line of Credit | Virginia Electric and Power Company
Short term Debt [Line Items]
Facility Limit		5,000,000,000
Subsequent Event | Joint Revolving Credit Facility 4 Billion and Joint Revolving Credit Facility 500 Million | Line of Credit | Dominion Gas Holdings, LLC
Short term Debt [Line Items]
Credit facility, to support letters of credit		$ 1,000,000,000.0

[1] These credit facilities mature in April 2019, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $2.0 billion of letters of credit.

[2] The weighted-average interest rates of the outstanding commercial paper supported by Dominion’s credit facilities were 0.62% and 0.38% at December 31, 2015 and 2014, respectively.

[3] Includes $4 million for fair value hedge valuation in 2014. Excludes $100 million of variable rate short-term notes scheduled to mature in May 2016 that were purchased and cancelled using the proceeds from the February 2016 issuance of senior notes that mature in 2018.

[4] Represents weighted-average coupon rates for debt outstanding as of December 31, 2015.

[5] The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion and Dominion Gas. Sub-limits for Virginia Power are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2015, the sub-limit for Virginia Power was an aggregate $1.75 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion. These credit facilities mature in April 2019, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.

[6] The weighted-average interest rates of the outstanding commercial paper supported by these credit facilities were 0.60% and 0.36% at December 31, 2015 and 2014, respectively.

[7] A maximum of a combined $1.5 billion of the facilities is available to Dominion Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion and Virginia Power. Sub-limits for Dominion Gas are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2015, the sub-limit for Dominion Gas was an aggregate $500 million. In January 2016, the aggregate sub-limit for Dominion Gas was increased to $1.0 billion. If Dominion Gas has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion. These credit facilities mature in April 2019, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.5 billion (or the sub-limit, whichever is less) of letters of credit.

[8] The weighted-average interest rate of the outstanding commercial paper supported by these credit facilities was 0.63% at December 31, 2015.

[9] In January 2016, this facility limit was increased from $4.0 billion to $5.0 billion.

[10] In January 2016, this facility limit was increased from $4.0 billion to $5.0 billion.