Employee Benefit Plans (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015		Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plans and OPEB plans	$ 0
Expected contribution to voluntary employees' beneficiary association	12,000,000
Dominion Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plans and OPEB plans	0
Expected contribution to voluntary employees' beneficiary association	12,000,000
Amounts due from Dominion	4,000,000	[1]	3,000,000	[1]
Pension Benefits | Dominion Gas Holdings, LLC | Dominion | Noncurrent Pension and Other Postretirement Benefit Assets
Defined Benefit Plan Disclosure [Line Items]
Amounts due from Dominion	623,000,000		614,000,000
Other Postretirement Benefits | Dominion Gas Holdings, LLC | Dominion | Other Deferred Credits and Other Liabilities
Defined Benefit Plan Disclosure [Line Items]
Amounts due to Dominion	$ 6,000,000		$ 7,000,000

[1] Amounts are presented in other current assets in Dominion Gas' Consolidated Balance Sheets.