Income Taxes (The Companies Deferred Income Taxes Components) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Total deferred income tax assets	$ 2,023	$ 2,142
Total deferred income tax liabilities	8,663	8,463
Total net deferred income tax liabilities	6,640	6,321
Total deferred income taxes:
Plant and equipment, primarily depreciation method and basis differences	5,895	5,383
Nuclear decommissioning	1,241	1,136
Deferred state income taxes	659	606
Federal benefit of deferred state income taxes	(231)	(212)
Deferred fuel, purchased energy and gas costs	27	(33)
Pension benefits	272	435
Other postretirement benefits	(17)	(78)
Loss and credit carryforwards	(1,434)	(797)
Valuation allowances	87	69
Partnership basis differences	304	125
Other	(163)	(313)
Total net deferred income tax liabilities	6,640	6,321
Virginia Electric and Power Company
Income Tax Contingency [Line Items]
Total deferred income tax assets	500	462
Total deferred income tax liabilities	4,915	4,498
Total net deferred income tax liabilities	4,415	4,036
Total deferred income taxes:
Plant and equipment, primarily depreciation method and basis differences	3,965	3,628
Nuclear decommissioning	474	441
Deferred state income taxes	299	285
Federal benefit of deferred state income taxes	(105)	(100)
Deferred fuel, purchased energy and gas costs	18	(50)
Pension benefits	(77)	(52)
Other postretirement benefits	13	(3)
Loss and credit carryforwards	(116)	(106)
Valuation allowances	0	0
Partnership basis differences	0	0
Other	(56)	(7)
Total net deferred income tax liabilities	4,415	4,036
Dominion Gas Holdings, LLC
Income Tax Contingency [Line Items]
Total deferred income tax assets	227	216
Total deferred income tax liabilities	2,289	2,103
Total net deferred income tax liabilities	2,062	1,887
Total deferred income taxes:
Plant and equipment, primarily depreciation method and basis differences	1,417	1,266
Nuclear decommissioning	0	0
Deferred state income taxes	207	182
Federal benefit of deferred state income taxes	(72)	(64)
Deferred fuel, purchased energy and gas costs	7	13
Pension benefits	567	522
Other postretirement benefits	(12)	(13)
Loss and credit carryforwards	(10)	(10)
Valuation allowances	0	0
Partnership basis differences	42	42
Other	(84)	(51)
Total net deferred income tax liabilities	$ 2,062	$ 1,887