Significant Accounting Policies (Depreciation Rates and Estimated Useful Life) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Increase in depreciation	38	19
Increase in depreciation, after tax	23	12
Dominion Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Decrease in depreciation		8
Decrease in depreciation, after tax		5
Generation
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.66%	2.71%	2.62%
Generation | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.66%	2.71%	2.62%
Transmission
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.38%	2.36%	2.17%
Transmission | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.34%	2.28%	1.98%
Transmission | Dominion Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.40%	2.43%	2.35%
Distribution
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	3.12%	3.13%	3.17%
Distribution | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	3.34%	3.33%	3.32%
Distribution | Dominion Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.47%	2.50%	2.66%
Storage
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.39%	2.43%	2.59%
Storage | Dominion Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.40%	2.43%	2.58%
Gas gathering and processing
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.81%	2.39%	2.49%
Gas gathering and processing | Dominion Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	2.82%	2.39%	2.50%
General and other
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	3.62%	3.82%	4.55%
General and other | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	3.29%	3.51%	4.32%
General and other | Dominion Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation rates	5.77%	5.93%	6.09%
Merchant generation-nuclear
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	44 years
Minimum | General and other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Minimum | Merchant generation-other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	15 years
Maximum | General and other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	59 years
Maximum | Merchant generation-other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	36 years