Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Details) - USD ($) $ in Millions		Jun. 30, 2017		Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Asset		$ 281	[1]	$ 279	[2]
Derivative Liabilities		150	[3]	155	[4]
Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset	[2]	167		194
Derivative Liabilities	[4]	74		31
Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		17
Derivative Liabilities		5		11
Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset		142	[5]	140	[6]
Current Assets | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset	[6]	55		66
Current Assets | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset	[7]	2
Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		5		10
Current Assets | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset				6
Current Assets | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset		137		130
Current Assets | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		55		60
Current Assets | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		2
Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset		139		139
Noncurrent Assets | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		112		128
Noncurrent Assets | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset	[8]	15
Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		9		7
Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		15
Noncurrent Assets | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		15
Noncurrent Assets | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset		115		132
Noncurrent Assets | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		112		128
Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities		104	[9]	128	[10]
Current Liabilities | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[10]	41		18
Current Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[7]	5		7
Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		40		33
Current Liabilities | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		31		8
Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		5		3
Current Liabilities | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities		5		3
Current Liabilities | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities		59		92
Current Liabilities | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		10		10
Current Liabilities | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				4
Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities		46		27
Noncurrent Liabilities | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		33		13
Noncurrent Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[8]			4
Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		44		20
Noncurrent Liabilities | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		33		13
Noncurrent Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities				3
Noncurrent Liabilities | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				3
Noncurrent Liabilities | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities		2		4
Noncurrent Liabilities | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				1
Fair Value – Derivatives under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		71	[1]	46	[2]
Derivative Liabilities		103	[3]	111	[4]
Fair Value – Derivatives under Hedge Accounting | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset	[2]	0		6
Derivative Liabilities	[4]	64		21
Fair Value – Derivatives under Hedge Accounting | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		17
Derivative Liabilities		5		11
Fair Value – Derivatives under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset		47	[5]	39	[6]
Fair Value – Derivatives under Hedge Accounting | Current Assets | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset	[6]	0		6
Fair Value – Derivatives under Hedge Accounting | Current Assets | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset	[7]	2
Fair Value – Derivatives under Hedge Accounting | Current Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		5		10
Fair Value – Derivatives under Hedge Accounting | Current Assets | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset				6
Fair Value – Derivatives under Hedge Accounting | Current Assets | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset		42		29
Fair Value – Derivatives under Hedge Accounting | Current Assets | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		0		0
Fair Value – Derivatives under Hedge Accounting | Current Assets | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		2
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset		24		7
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		0		0
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset	[8]	15
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Asset		9		7
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Asset		15
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		15
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset		0		0
Fair Value – Derivatives under Hedge Accounting | Noncurrent Assets | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		0		0
Fair Value – Derivatives under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities		59	[9]	87	[10]
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[10]	31		8
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[7]	5		7
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		40		33
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		31		8
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities		5		3
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities		5		3
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities		14		51
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0		0
Fair Value – Derivatives under Hedge Accounting | Current Liabilities | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				4
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities		44		24
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		33		13
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[8]			4
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		44		20
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		33		13
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities				3
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				3
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0		1
Fair Value – Derivatives under Hedge Accounting | Noncurrent Liabilities | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				1
Fair Value – Derivatives not under Hedge Accounting
Derivatives, Fair Value [Line Items]
Derivative Asset		210	[1]	233	[2]
Derivative Liabilities		47	[3]	44	[4]
Fair Value – Derivatives not under Hedge Accounting | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset	[2]	167		188
Derivative Liabilities	[4]	10		10
Fair Value – Derivatives not under Hedge Accounting | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Derivative Liabilities		0		0
Fair Value – Derivatives not under Hedge Accounting | Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset		95	[5]	101	[6]
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset	[6]	55		60
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset	[7]	0
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 | Current Assets | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset				0
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset		95		101
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		55		60
Fair Value – Derivatives not under Hedge Accounting | Current Assets | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets
Derivatives, Fair Value [Line Items]
Derivative Asset		115		132
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		112		128
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset	[8]	0
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 | Noncurrent Assets | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Asset		0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Asset		115		132
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Assets | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Asset		112		128
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities		45	[9]	41	[10]
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[10]	10		10
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[7]	0		0
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 | Interest rate | Virginia Electric and Power Company
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		0
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0		0
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities		45		41
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Commodity contracts | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		10		10
Fair Value – Derivatives not under Hedge Accounting | Current Liabilities | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities		2		3
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0		0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities	[8]			0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0		0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Interest rate | Virginia Electric and Power Company
Derivatives, Fair Value [Line Items]
Derivative Liabilities		0		0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Foreign currency
Derivatives, Fair Value [Line Items]
Derivative Liabilities				0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Foreign currency | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				0
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities		$ 2		3
Fair Value – Derivatives not under Hedge Accounting | Noncurrent Liabilities | Commodity contracts | Dominion Energy Gas Holdings, LLC
Derivatives, Fair Value [Line Items]
Derivative Liabilities				$ 0

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

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

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

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

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

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

[7] Current derivative assets are presented in other current assets in Dominion Energy Gas’ Consolidated Balance Sheets. Noncurrent derivatives assets are presented in other deferred charges and other assets in Dominion Energy Gas’ Consolidated Balance Sheets. Current derivative liabilities are presented in other current liabilities in Dominion Energy Gas' Consolidated Balance Sheets.

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

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

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