Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Details) - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Asset		$ 295	$ 388
Derivative Liabilities		422	343
Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[1]	173	255
Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		164	252
Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		9	3
Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[2]	122	133
Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		104	112
Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		10	21
Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		8
Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[3]	286	312
Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		100	148
Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		182	164
Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		4
Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	136	31
Noncurrent Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		11	12
Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		125	19
Fair Value – Derivatives under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		90	128
Derivative Liabilities		334	215
Fair Value – Derivatives under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[1]	68	104
Fair Value – Derivatives under Hedge Accounting | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		59	101
Fair Value – Derivatives under Hedge Accounting | Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		9	3
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[2]	22	24
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		4	3
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		10	21
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		8
Fair Value – Derivatives under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[3]	208	196
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		22	32
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		182	164
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		4
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	126	19
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		1	0
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		125	19
Fair Value – Derivatives not under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		205	260
Derivative Liabilities		88	128
Fair Value – Derivatives not under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[1]	105	151
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		105	151
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		0	0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[2]	100	109
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		100	109
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		0	0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[3]	78	116
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		78	116
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0	0
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[4]	10	12
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		10	12
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0	0
Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		118	127
Derivative Liabilities		291	86
Virginia Electric and Power Company | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[5]	27	18
Virginia Electric and Power Company | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		25	18
Virginia Electric and Power Company | Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		2
Virginia Electric and Power Company | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[6]	91	109
Virginia Electric and Power Company | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		91	96
Virginia Electric and Power Company | Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset			13
Virginia Electric and Power Company | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[7]	161	80
Virginia Electric and Power Company | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		19	23
Virginia Electric and Power Company | Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		142	57
Virginia Electric and Power Company | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[8]	130	6
Virginia Electric and Power Company | Noncurrent Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		5	4
Virginia Electric and Power Company | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		125	2
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		2	13
Derivative Liabilities		267	59
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[5]	2	0
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		0	0
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		2
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[6]	0	13
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		0	0
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset			13
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[7]	142	57
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0	0
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		142	57
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[8]	125	2
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0	0
Virginia Electric and Power Company | Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		125	2
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		116	114
Derivative Liabilities		24	27
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[5]	25	18
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		25	18
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[6]	91	96
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		91	96
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset			0
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[7]	19	23
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		19	23
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0	0
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[8]	5	4
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		5	4
Virginia Electric and Power Company | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0	0
Dominion Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		14	11
Derivative Liabilities		6	14
Dominion Gas Holdings, LLC | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[9]	6	10
Dominion Gas Holdings, LLC | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		6	10
Dominion Gas Holdings, LLC | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[10]	8	1
Dominion Gas Holdings, LLC | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset			1
Dominion Gas Holdings, LLC | Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		8
Dominion Gas Holdings, LLC | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[11]	6
Dominion Gas Holdings, LLC | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		2
Dominion Gas Holdings, LLC | Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		4
Dominion Gas Holdings, LLC | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[12]		14
Dominion Gas Holdings, LLC | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities			14
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		9	11
Derivative Liabilities		6	14
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[9]	1	10
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		1	10
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[10]	8	1
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset			1
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		8
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[11]	6
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		2
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		4
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[12]		14
Dominion Gas Holdings, LLC | Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities			14
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		5	0
Derivative Liabilities		0	0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[9]	5	0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Current Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset		5	0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	[10]	0	0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset			0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[11]	0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Commodity
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		$ 0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[12]		0
Dominion Gas Holdings, LLC | Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities			$ 0

[1] Current derivative assets are presented in other current assets in Dominion’s Consolidated Balance Sheets.

[2] Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion’s Consolidated Balance Sheets.

[3] Current derivative liabilities are presented in other current liabilities in Dominion's Consolidated Balance Sheets.

[4] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion’s Consolidated Balance Sheets.

[5] Current derivative assets are presented in other current assets in Virginia Power's Consolidated Balance Sheets.

[6] Noncurrent derivative assets are presented in other deferred charges and other assets in Virginia Power's Consolidated Balance Sheets.

[7] Current derivative liabilities are presented in other current liabilities in Virginia Power's Consolidated Balance Sheets.

[8] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Virginia Power’s Consolidated Balance Sheets.

[9] Current derivative assets are presented in other current assets in Dominion Gas' Consolidated Balance Sheets.

[10] Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Gas’ Consolidated Balance Sheets.

[11] Current derivative liabilities are presented in other current liabilities in Dominion Gas' Consolidated Balance Sheets.

[12] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Gas’ Consolidated Balance Sheets.