Derivatives and Hedge Accounting Activities (Fair Values of our Derivatives) (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		$ 279	$ 388
Derivative liabilities		155	343
Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		140	255
Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		130	252
Current Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		10	3
Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[1]	139	133
Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		132	112
Noncurrent Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		7	21
Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[2]	128	312
Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		92	148
Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		33	164
Current Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[3]	27	31
Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		4	12
Noncurrent Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		20	19
Noncurrent Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Fair Value - Derivatives under Hedge Accounting
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		46	128
Derivative liabilities		111	215
Fair Value - Derivatives under Hedge Accounting | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		39	104
Fair Value - Derivatives under Hedge Accounting | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		29	101
Fair Value - Derivatives under Hedge Accounting | Current Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		10	3
Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[1]	7	24
Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0	3
Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		7	21
Fair Value - Derivatives under Hedge Accounting | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[2]	87	196
Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		51	32
Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		33	164
Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[3]	24	19
Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		1	0
Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		20	19
Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Fair Value - Derivatives not under Hedge Accounting
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		233	260
Derivative liabilities		44	128
Fair Value - Derivatives not under Hedge Accounting | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		101	151
Fair Value - Derivatives not under Hedge Accounting | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		101	151
Fair Value - Derivatives not under Hedge Accounting | Current Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0	0
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[1]	132	109
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		132	109
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0	0
Fair Value - Derivatives not under Hedge Accounting | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[2]	41	116
Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		41	116
Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0	0
Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[3]	3	12
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3	12
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0	0
Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0
Virginia Electric and Power Company
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		194	127
Derivative liabilities		31	86
Virginia Electric and Power Company | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[4]	66	18
Virginia Electric and Power Company | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		60	18
Virginia Electric and Power Company | Current Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		6
Virginia Electric and Power Company | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		128	109
Virginia Electric and Power Company | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		128	96
Virginia Electric and Power Company | Noncurrent Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			13
Virginia Electric and Power Company | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[5]	18	80
Virginia Electric and Power Company | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		10	23
Virginia Electric and Power Company | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		8	57
Virginia Electric and Power Company | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[6]	13	6
Virginia Electric and Power Company | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities			4
Virginia Electric and Power Company | Noncurrent Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		13	2
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		6	13
Derivative liabilities		21	59
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[4]	6	0
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0	0
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Current Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		6
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0	13
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0	0
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			13
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[5]	8	57
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0	0
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		8	57
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[6]	13	2
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities			0
Virginia Electric and Power Company | Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		13	2
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		188	114
Derivative liabilities		10	27
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[4]	60	18
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		60	18
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Current Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		0
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		128	96
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets		128	96
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			0
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[5]	10	23
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		10	23
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[6]	0	4
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities			4
Virginia Electric and Power Company | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0	0
Dominion Gas Holdings, LLC
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			11
Derivative liabilities		11	14
Dominion Gas Holdings, LLC | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[7]		10
Dominion Gas Holdings, LLC | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			10
Dominion Gas Holdings, LLC | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[8]		1
Dominion Gas Holdings, LLC | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			1
Dominion Gas Holdings, LLC | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[9]	7	14
Dominion Gas Holdings, LLC | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		4
Dominion Gas Holdings, LLC | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities			14
Dominion Gas Holdings, LLC | Current Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Dominion Gas Holdings, LLC | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[10]	4
Dominion Gas Holdings, LLC | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		1
Dominion Gas Holdings, LLC | Noncurrent Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			11
Derivative liabilities		11	14
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[7]		10
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			10
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[8]		1
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			1
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[9]	7	14
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		4
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities			14
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Current Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[10]	4
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		1
Dominion Gas Holdings, LLC | Fair Value - Derivatives under Hedge Accounting | Noncurrent Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		3
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			0
Derivative liabilities		0	0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[7]		0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Current Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets	[8]		0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative assets			0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[9]	0	0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities			$ 0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Current Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities	[10]	0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		0
Dominion Gas Holdings, LLC | Fair Value - Derivatives not under Hedge Accounting | Noncurrent Liabilities | Foreign currency
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liabilities		$ 0

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

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

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

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

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

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

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

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

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

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