Income Taxes (The Companies Deferred Income Taxes Components) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Total deferred income tax assets	$ 1,152	$ 2,023
Total deferred income tax liabilities	8,552	8,663
Total deferred income tax liabilities	7,400	6,640
Total deferred income taxes:
Plant and equipment, primarily depreciation method and basis differences	6,299	5,895
Nuclear decommissioning	1,158	1,241
Deferred state income taxes	646	659
Federal benefit of deferred state income taxes	(226)	(231)
Deferred fuel, purchased energy and gas costs	(1)	27
Pension benefits	291	272
Other postretirement benefits	(15)	(17)
Loss and credit carryforwards	(1,004)	(1,434)
Valuation allowances	73	87
Partnership basis differences	367	304
Other	(188)	(163)
Total deferred income tax liabilities	7,400	6,640
Virginia Electric and Power Company
Income Tax Contingency [Line Items]
Total deferred income tax assets	164	500
Total deferred income tax liabilities	4,805	4,915
Total deferred income tax liabilities	4,641	4,415
Total deferred income taxes:
Plant and equipment, primarily depreciation method and basis differences	4,133	3,965
Nuclear decommissioning	378	474
Deferred state income taxes	302	299
Federal benefit of deferred state income taxes	(106)	(105)
Deferred fuel, purchased energy and gas costs	(3)	18
Pension benefits	(99)	(77)
Other postretirement benefits	30	13
Loss and credit carryforwards	(53)	(116)
Valuation allowances	0	0
Partnership basis differences	0	0
Other	59	(56)
Total deferred income tax liabilities	4,641	4,415
Dominion Gas Holdings, LLC
Income Tax Contingency [Line Items]
Total deferred income tax assets	129	227
Total deferred income tax liabilities	2,343	2,289
Total deferred income tax liabilities	2,214	2,062
Total deferred income taxes:
Plant and equipment, primarily depreciation method and basis differences	1,541	1,417
Nuclear decommissioning	0	0
Deferred state income taxes	205	207
Federal benefit of deferred state income taxes	(72)	(72)
Deferred fuel, purchased energy and gas costs	1	7
Pension benefits	613	567
Other postretirement benefits	(7)	(12)
Loss and credit carryforwards	(4)	(10)
Valuation allowances	0	0
Partnership basis differences	41	42
Other	(104)	(84)
Total deferred income tax liabilities	$ 2,214	$ 2,062