Virginia Electric & Power 8-K 6 Jun 18 Other Events Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2017
Document Information [Line Items]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Trading Symbol	D
Entity Registrant Name	DOMINION ENERGY INC /VA/
Entity Central Index Key	715,957
Virginia Electric and Power Company
Document Information [Line Items]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Trading Symbol	VEL - PE
Entity Registrant Name	VIRGINIA ELECTRIC & POWER CO
Dominion Energy Gas Holdings, LLC
Document Information [Line Items]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Entity Registrant Name	Dominion Energy Gas Holdings, LLC
Entity Central Index Key	1,603,291

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Revenue	[1]	$ 12,586	$ 11,737	$ 11,683
Operating Expenses
Electric fuel and other energy-related purchases		2,301	2,333	2,725
Purchased electric capacity		6	99	330
Purchased gas		701	459	551
Other operations and maintenance		3,068	3,243	2,711
Depreciation and amortization		1,905	1,559	1,395
Other taxes		668	596	551
Total operating expenses		8,649	8,289	8,263
Income from operations		3,937	3,448	3,420
Earnings from equity method investee		(18)	111	56
Other income	[1]	358	429	312
Interest and related charges		1,205	1,010	904
Income from operations before income tax expense		3,090	2,867	2,828
Income tax expense		(30)	655	905
Net Income Including Noncontrolling Interests		3,120	2,212	1,923
Noncontrolling Interests		121	89	24
Net Income		$ 2,999	$ 2,123	$ 1,899
Earnings Per Common Share
Net income attributable to Dominion Energy-Basic		$ 4.72	$ 3.44	$ 3.21
Net income attributable to Dominion Energy-Diluted		4.72	3.44	3.20
Dividends Declared Per Common Share		$ 3.035	$ 2.800	$ 2.590
Virginia Electric and Power Company
Operating Revenue		$ 7,556	$ 7,588	$ 7,622
Operating Expenses
Electric fuel and other energy-related purchases	[2]	1,909	1,973	2,320
Purchased electric capacity		6	99	330
Affiliated suppliers		309	310	279
Other		1,169	1,547	1,355
Depreciation and amortization		1,141	1,025	953
Other taxes		290	284	264
Total operating expenses		4,824	5,238	5,501
Income from operations		2,732	2,350	2,121
Other income		76	56	68
Interest and related charges	[2]	494	461	443
Income from operations before income tax expense		2,314	1,945	1,746
Income tax expense		774	727	659
Net Income		1,540	1,218	1,087
Dominion Energy Gas Holdings, LLC
Operating Revenue	[3]	1,814	1,638	1,716
Operating Expenses
Purchased gas	[3]	132	109	133
Other energy-related purchases	[3]	21	12	21
Affiliated suppliers		87	81	64
Other	[3]	524	469	388
Depreciation and amortization		227	204	217
Other taxes		185	170	166
Total operating expenses		1,176	1,045	989
Income from operations		638	593	727
Earnings from equity method investee		21	21	23
Other income		104	87	63
Interest and related charges	[3]	97	94	73
Income from operations before income tax expense		666	607	740
Income tax expense		51	215	283
Net Income		$ 615	$ 392	$ 457
[1]	See Note 9 for amounts attributable to related parties.
[2]	See Note 24 for amounts attributable to affiliates.
[3]	See Note 24 for amounts attributable to related parties.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income including noncontrolling interests	$ 3,120	$ 2,212	$ 1,923
Net income	2,999	2,123	1,899
Other comprehensive income (loss), net of taxes:
Net deferred gains (losses) on derivatives-hedging activities, net of tax	8	55	110
Changes in unrealized net gains (losses) on investment securities, net of tax	215	93	6
Changes in net unrecognized pension and other postretirement benefit costs, net of $32, $189 and $29 tax	(69)	(319)	(66)
Amounts reclassified to net income (loss):
Net derivative (gains) losses-hedging activities, net of tax	(29)	(159)	(108)
Net realized gains on investment securities, net of tax	(37)	(28)	(50)
Net pension and other postretirement benefit costs, net of tax	50	34	51
Changes in other comprehensive loss from equity method investees, net of tax	3	(1)	(1)
Net current period other comprehensive income (loss)	141	(325)	(58)
Comprehensive income including noncontrolling interests	3,261	1,887	1,865
Comprehensive income attributable to noncontrolling interests	122	89	24
Comprehensive income attributable to Dominion Energy	3,139	1,798	1,841
Virginia Electric and Power Company
Net income	1,540	1,218	1,087
Other comprehensive income (loss), net of taxes:
Net deferred gains (losses) on derivatives-hedging activities, net of tax	(5)	(2)	(1)
Changes in unrealized net gains (losses) on investment securities, net of tax	24	11	(4)
Amounts reclassified to net income (loss):
Net derivative (gains) losses-hedging activities, net of tax	1	1	1
Net realized gains on investment securities, net of tax	(4)	(4)	(6)
Net current period other comprehensive income (loss)	16	6	(10)
Comprehensive income attributable to Dominion Energy	1,556	1,224	1,077
Dominion Energy Gas Holdings, LLC
Net income	615	392	457
Other comprehensive income (loss), net of taxes:
Net deferred gains (losses) on derivatives-hedging activities, net of tax	5	(16)	6
Changes in net unrecognized pension and other postretirement benefit costs, net of $32, $189 and $29 tax	20	(20)	(20)
Amounts reclassified to net income (loss):
Net derivative (gains) losses-hedging activities, net of tax	(4)	9	(3)
Net pension and other postretirement benefit costs, net of tax	4	3	4
Net current period other comprehensive income (loss)	25	(24)	(13)
Comprehensive income attributable to Dominion Energy	$ 640	$ 368	$ 444

Consolidated Statements of Com4

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net deferred gains (losses) on derivative-hedging activities, tax	$ (3)	$ (37)	$ (74)
Changes in unrealized net gains (losses) on investment securities, tax	(121)	(53)	23
Changes in net unrecognized pension and other postretirement benefit costs, tax	32	189	29
Net derivative (gains) losses on derivative-hedging activities, tax	18	100	68
Net realized gains on investment securities, tax	21	15	29
Net pension and other postretirement benefit costs, tax	(32)	(22)	(35)
Changes in other comprehensive income (loss) from equity method investees, tax	(2)		1
Virginia Electric and Power Company
Net deferred gains (losses) on derivative-hedging activities, tax	3	1	2
Changes in unrealized net gains (losses) on investment securities, tax	(16)	(7)	1
Net derivative (gains) losses on derivative-hedging activities, tax	0	0	0
Net realized gains on investment securities, tax	3	2	4
Dominion Energy Gas Holdings, LLC
Net deferred gains (losses) on derivative-hedging activities, tax	(3)	10	(4)
Changes in net unrecognized pension and other postretirement benefit costs, tax	(8)	14	13
Net derivative (gains) losses on derivative-hedging activities, tax	3	(6)	3
Net pension and other postretirement benefit costs, tax	$ (2)	$ (2)	$ (3)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents		$ 120	$ 261
Customer receivables (less allowance for doubtful accounts)		1,660	1,523
Other receivables (less allowance for doubtful accounts)	[1]	126	183
Inventories
Materials and supplies		1,049	1,087
Fossil fuel		328	341
Gas stored		100	96
Prepayments		260	194
Regulatory assets		294	244
Other		397	319
Total current assets		4,334	4,248
Investments
Nuclear decommissioning trust funds		5,093	4,484
Investment in equity method affiliates		1,544	1,561
Other		327	298
Total investments		6,964	6,343
Property, Plant and Equipment
Property, plant and equipment		74,823	69,556
Accumulated depreciation, depletion and amortization		(21,065)	(19,592)
Total property, plant and equipment, net		53,758	49,964
Deferred Charges and Other Assets
Goodwill	[2]	6,405	6,399
Pension and other postretirement benefit assets		1,378	1,078
Intangible assets, net		685	618
Regulatory assets		2,480	2,473
Other		581	487
Total deferred charges and other assets		11,529	11,055
Total assets		76,585	71,610
Current Liabilities
Securities due within one year		3,078	1,709
Short-term debt		3,298	3,155
Accounts payable		875	1,000
Accrued interest, payroll and taxes		848	798
Other		1,537	1,453
Total current liabilities		9,636	8,115
Long-Term Debt
Long-term debt		25,588	24,878
Junior subordinated notes		3,981	2,980
Remarketable subordinated notes		1,379	2,373
Long-Term Debt		30,948	30,231
Deferred Credits and Other Liabilities
Deferred income taxes and investment tax credits		4,523	8,602
Regulatory liabilities		6,916	2,622
Asset retirement obligations		2,169	2,236
Pension and other postretirement benefit liability		2,160	2,112
Other	[3]	863	852
Total deferred credits and other liabilities		16,631	16,424
Total liabilities		57,215	54,770
Commitments and Contingencies
Equity
Common stock-no par	[4]	9,865	8,550
Retained earnings		7,936	6,854
Accumulated other comprehensive loss		(659)	(799)
Total common shareholders' equity		17,142	14,605
Noncontrolling interests		2,228	2,235
Total equity		19,370	16,840
Total liabilities and equity		76,585	71,610
Virginia Electric and Power Company
Current Assets
Cash and cash equivalents		14	11
Customer receivables (less allowance for doubtful accounts)		951	892
Other receivables (less allowance for doubtful accounts)		64	99
Affiliated receivables		3	112
Inventories
Materials and supplies		531	525
Fossil fuel		319	328
Prepayments		27	30
Regulatory assets		205	179
Other	[5]	110	72
Total current assets		2,224	2,248
Investments
Nuclear decommissioning trust funds		2,399	2,106
Other		3	3
Total investments		2,402	2,109
Property, Plant and Equipment
Property, plant and equipment		42,329	40,030
Accumulated depreciation, depletion and amortization		(13,277)	(12,436)
Total property, plant and equipment, net		29,052	27,594
Deferred Charges and Other Assets
Pension and other postretirement benefit assets	[5]	199	130
Intangible assets, net		233	225
Regulatory assets		810	770
Derivative assets	[5]	91	128
Other		128	104
Total deferred charges and other assets		1,461	1,357
Total assets		35,139	33,308
Current Liabilities
Securities due within one year		850	678
Short-term debt		542	65
Accounts payable		361	444
Payables to affiliates		125	109
Affiliated current borrowings		33	262
Accrued interest, payroll and taxes		256	239
Asset retirement obligations		216	181
Other	[5]	537	544
Total current liabilities		2,920	2,522
Long-Term Debt
Long-Term Debt		10,496	9,852
Deferred Credits and Other Liabilities
Deferred income taxes and investment tax credits		2,728	5,103
Regulatory liabilities		4,760	1,962
Asset retirement obligations		1,149	1,262
Pension and other postretirement benefit liability	[5]	505	396
Other		357	346
Total deferred credits and other liabilities		9,499	9,069
Total liabilities		22,915	21,443
Commitments and Contingencies
Equity
Common stock-no par	[6]	5,738	5,738
Other paid-in capital		1,113	1,113
Retained earnings		5,311	4,968
Accumulated other comprehensive loss		62	46
Total common shareholders' equity		12,224	11,865
Total equity		12,224	11,865
Total liabilities and equity		35,139	33,308
Dominion Energy Gas Holdings, LLC
Current Assets
Cash and cash equivalents		4	23
Customer receivables (less allowance for doubtful accounts)	[7]	297	281
Other receivables (less allowance for doubtful accounts)	[7]	15	13
Affiliated receivables		10	17
Inventories
Materials and supplies		55	57
Gas stored		9	13
Prepayments	[7]	112	94
Regulatory assets	[8]	26	26
Gas imbalances		46	37
Other	[7]	52	47
Total current assets		600	582
Investments
Investment in equity method affiliates		95	98
Total investments		97	99
Property, Plant and Equipment
Property, plant and equipment		11,173	10,475
Accumulated depreciation, depletion and amortization		(3,018)	(2,851)
Total property, plant and equipment, net		8,155	7,624
Deferred Charges and Other Assets
Goodwill	[2]	542	542
Pension and other postretirement benefit assets		1,828	1,557
Intangible assets, net		109	98
Regulatory assets		511	577
Other	[7]	98	63
Total deferred charges and other assets	[7]	3,088	2,837
Total assets		11,940	11,142
Current Liabilities
Short-term debt		629	460
Accounts payable		193	221
Payables to affiliates		62	29
Affiliated current borrowings		18	118
Accrued interest, payroll and taxes		250	225
Other	[7]	189	162
Total current liabilities		1,341	1,215
Long-Term Debt
Long-Term Debt		3,570	3,528
Deferred Credits and Other Liabilities
Deferred income taxes and investment tax credits		1,454	2,438
Regulatory liabilities		1,227	219
Other	[7]	185	206
Total deferred credits and other liabilities		2,866	2,863
Total liabilities		7,777	7,606
Commitments and Contingencies
Equity
Membership interests		4,261	3,659
Accumulated other comprehensive loss		(98)	(123)
Total equity		4,163	3,536
Total liabilities and equity		$ 11,940	$ 11,142
[1]	See Note 9 for amounts attributable to related parties.
[2]	Goodwill amounts do not contain any accumulated impairment losses.
[3]	See notes 3 and 9 for amounts attributable to related parties.
[4]	1 billion shares authorized; 645 million shares and 628 million shares outstanding at December 31, 2017 and 2016, respectively.
[5]	See Note 24 for amounts attributable to affiliates.
[6]	500,000 shares authorized; 274,723 shares outstanding at December 31, 2017 and 2016.
[7]	See Note 24 for amounts attributable to related parties.
[8]	Current regulatory assets are presented in other current assets in the Consolidated Balance Sheets of Dominion Energy Gas.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Customer receivables, allowance for doubtful accounts		$ 17	$ 18
Other receivables, allowance for doubtful accounts		$ 2	$ 2
Common stock, shares authorized		1,000,000,000	1,000,000,000
Common stock, shares outstanding		645,000,000	628,000,000
Virginia Electric and Power Company
Customer receivables, allowance for doubtful accounts		$ 10	$ 10
Other receivables, allowance for doubtful accounts		$ 1	$ 1
Common stock, shares authorized		500,000	500,000
Common stock, shares outstanding		274,723	274,723
Dominion Energy Gas Holdings, LLC
Customer receivables, allowance for doubtful accounts	[1]	$ 1	$ 1
Other receivables, allowance for doubtful accounts	[1]	$ 1	$ 1
[1]	See Note 24 for amounts attributable to related parties.

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Millions	Total	Sun Edison Inc	NRG Energy, Inc	Virginia Electric and Power Company	Dominion Energy Gas Holdings, LLC	Common Units	Convertible Preferred Units	Common Stock	Common StockVirginia Electric and Power Company	Retained Earnings	Retained EarningsVirginia Electric and Power Company	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)Virginia Electric and Power Company	Accumulated Other Comprehensive Income (Loss)Dominion Energy Gas Holdings, LLC	Total Common Shareholders' Equity	Noncontrolling Interests	Noncontrolling InterestsSun Edison Inc	Noncontrolling InterestsNRG Energy, Inc	Noncontrolling InterestsCommon Units	Noncontrolling InterestsConvertible Preferred Units	Other Paid-In CapitalVirginia Electric and Power Company	Member UnitsDominion Energy Gas Holdings, LLC
Beginning balance at Dec. 31, 2014	$ 11,957			$ 10,055	$ 3,566			$ 5,876	$ 5,738	$ 6,095	$ 3,154	$ (416)	$ 50	$ (86)	$ 11,555	$ 402					$ 1,113	$ 3,652
Beginning balance (in shares) at Dec. 31, 2014								585,000	275
Net income including noncontrolling interests	1,923									1,899					1,899	24
Net income attributable to Dominion	1,899			$ 1,087	457						1,087											457
Dominion Energy Midstream's acquisition of interest in Iroquois	216															216
Contributions to Four Brothers and Three Cedars		$ 103															$ 103
Distributions					(692)																	(692)
Acquisition of Four Brothers and Three Cedars	47															47
Sale of interest in merchant solar projects	205							$ 26							26	179
Purchase of Dominion Energy Midstream common units	(25)							(6)							(6)	(19)
Issuance of common stock	786							$ 786							786
Issuance of common stock (in shares)				0				11,000
Stock awards (net of change in unearned compensation)	13							$ 13							13
Dividends	(1,536)			$ (491)						(1,536)	(491)				(1,536)
Dominion Energy Midstream distributions	(16)															(16)
Other comprehensive income (loss), net of tax	(58)			(10)	(13)							(58)	(10)	(13)	(58)
Other	(13)							(15)							(15)	2
Ending balance at Dec. 31, 2015	13,602			10,641	3,318			$ 6,680	$ 5,738	6,458	3,750	(474)	40	(99)	12,664	938					1,113	3,417
Ending Balance (in shares) at Dec. 31, 2015								596,000	275
Net income including noncontrolling interests	2,212									2,123					2,123	89
Net income attributable to Dominion	2,123			$ 1,218	392						1,218											392
Dominion Energy Midstream's acquisition of interest in Iroquois						$ 482	$ 490												$ 482	$ 490
Contributions to Four Brothers and Three Cedars		$ 189															$ 189
Distributions					(150)																	(150)
Sale of interest in merchant solar projects	139							$ 22							22	117
Purchase of Dominion Energy Midstream common units	(17)							(3)							(3)	(14)
Issuance of common stock	2,152							$ 2,152							2,152
Issuance of common stock (in shares)				0				32,000
Stock awards (net of change in unearned compensation)	14							$ 14							14
Present value of stock purchase contract payments related to RSNs(1)	(191)							(191)							(191)
Tax effect of Dominion Energy Questar Pipeline contribution to Dominion Energy Midstream	(116)							(116)							(116)
Dividends	(1,789)									(1,727)					(1,727)	(62)
Other comprehensive income (loss), net of tax	(325)			$ 6	(24)							(325)	6	(24)	(325)
Other	(2)							(8)							(8)	6
Ending balance at Dec. 31, 2016	16,840			11,865	3,536			$ 8,550	$ 5,738	6,854	4,968	(799)	46	(123)	14,605	2,235					1,113	3,659
Ending Balance (in shares) at Dec. 31, 2016								628,000	275,000
Net income including noncontrolling interests	3,120									2,999					2,999	121
Net income attributable to Dominion	2,999			$ 1,540	615						1,540											615
Dominion Energy Midstream's acquisition of interest in Iroquois						$ 18													$ 18
Contributions to Four Brothers and Three Cedars			$ 9															$ 9
Distributions					(15)																	(15)
Issuance of common stock	1,302							$ 1,302							1,302
Issuance of common stock (in shares)				0				17,000
Stock awards (net of change in unearned compensation)	22							$ 22							22
Dividends	(2,087)			$ (1,199)						(1,931)	(1,199)				(1,931)	(156)
Other comprehensive income (loss), net of tax	141			16	25							140	16	25	140	1
Other	5			2	2			(9)		14	2				5							2
Ending balance at Dec. 31, 2017	$ 19,370			$ 12,224	$ 4,163			$ 9,865	$ 5,738	$ 7,936	$ 5,311	$ (659)	$ 62	$ (98)	$ 17,142	$ 2,228					$ 1,113	$ 4,261
Ending Balance (in shares) at Dec. 31, 2017								645,000	275,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Activities
Net income including noncontrolling interests		$ 3,120	$ 2,212	$ 1,923
Net income		2,999	2,123	1,899
Adjustments to reconcile net income including noncontrolling interests to net cash provided by operating activities:
Depreciation, depletion and amortization (including nuclear fuel)		2,202	1,849	1,669
Deferred income taxes and investment tax credits		(3)	725	854
Current income tax for Dominion Energy Questar Pipeline contribution to Dominion Energy Midstream			(212)
Proceeds from assignment of rental portfolio		91
Gains on the sales of assets		(148)	(50)	(123)
Charges associated with equity method investments		158
Charges associated with future ash pond and landfill closure costs			197	99
Contribution to pension plan		(75)
Other adjustments		(84)	(84)	(26)
Changes in:
Accounts receivable		(103)	(286)	294
Inventories		15	1	(26)
Deferred fuel and purchased gas costs, net		(71)	54	94
Prepayments		(62)	21	(25)
Accounts payable		(89)	97	(199)
Accrued interest, payroll and taxes		64	203	(52)
Margin deposit assets and liabilities		(10)	(66)	237
Net realized and unrealized changes related to derivative activities		44	(335)	(176)
Asset retirement obligations		(94)	(61)	(4)
Pension and other postretirement benefits		(177)	(152)	(51)
Other operating assets and liabilities		(276)	38	3
Net cash provided by operating activities		4,502	4,151	4,491
Investing Activities
Plant construction and other property additions (including nuclear fuel)		(5,504)	(6,085)	(5,575)
Acquisition of Dominion Energy Questar, net of cash acquired			(4,381)
Acquisition of solar development projects		(405)	(40)	(418)
Acquisition of DECG				(497)
Proceeds from sales of securities		1,831	1,422	1,340
Purchases of securities		(1,940)	(1,504)	(1,326)
Sale of certain retail energy marketing assets		68
Proceeds from assignment of shale development rights		70	10	79
Contributions to equity method affiliates		(370)	(198)	(51)
Distributions from equity method affiliates		275	2
Other		33	83	(65)
Net cash used in investing activities		(5,942)	(10,691)	(6,513)
Financing Activities
Issuance (repayment) of short-term debt, net		143	(654)	734
Issuance of short-term notes			1,200	600
Repayment and repurchase of short-term notes		(250)	(1,800)	(400)
Issuance and remarketing of long-term debt		3,880	7,722	2,962
Repayment and repurchase of long-term debt		(1,572)	(1,610)	(892)
Net proceeds from issuance of Dominion Energy Midstream common units		18	482
Net proceeds from issuance of Dominion Energy Midstream preferred units			490
Proceeds from sale of interest in merchant solar projects			117	184
Contributions from NRG and SunEdison to Four Brothers and Three Cedars		9	189	103
Issuance of common stock		1,302	2,152	786
Common dividend payments		(1,931)	(1,727)	(1,536)
Other		(296)	(331)	(224)
Net cash provided by (used in) financing activities		1,303	6,230	2,317
Increase (decrease) in cash, restricted cash and equivalents		(137)	(310)	295
Cash, restricted cash and equivalents at beginning of year		322	632	337
Cash, restricted cash and equivalents at end of year		185	322	632
Supplemental Cash Flow Information
Interest and related charges, excluding capitalized amounts		1,083	905	843
Income taxes		9	145	75
Significant noncash investing and financing activities:
Accrued capital expenditures	[1]	343	427	478
Guarantee provided to equity method affiliate		30
Dominion Energy Midstream's acquisition of a noncontrolling partnership interest in Iroquois in exchange for issuance of Dominion Energy Midstream common units	[1]			216
Virginia Electric and Power Company
Operating Activities
Net income		1,540	1,218	1,087
Adjustments to reconcile net income including noncontrolling interests to net cash provided by operating activities:
Depreciation, depletion and amortization (including nuclear fuel)		1,333	1,210	1,121
Deferred income taxes and investment tax credits		269	469	251
Proceeds from assignment of rental portfolio		91
Charges associated with future ash pond and landfill closure costs			197	99
Other adjustments		(36)	(16)	(27)
Changes in:
Accounts receivable		(27)	(65)	128
Affiliated accounts receivable and payable		125	220	(314)
Inventories		3	20	(20)
Deferred fuel and purchased gas costs, net		(59)	69	64
Prepayments		3	8	214
Accounts payable		(42)	25	(75)
Accrued interest, payroll and taxes		17	49	(9)
Net realized and unrealized changes related to derivative activities		13	(153)	(67)
Asset retirement obligations		(88)	(59)	10
Other operating assets and liabilities		(181)	77	93
Net cash provided by operating activities		2,961	3,269	2,555
Investing Activities
Plant construction and other property additions (including nuclear fuel)		(2,496)	(2,489)	(2,474)
Purchases of nuclear fuel		(192)	(153)	(172)
Acquisition of solar development projects		(41)	(7)	(43)
Proceeds from sales of securities		849	733	639
Purchases of securities		(884)	(775)	(651)
Other		(41)	(33)	(87)
Net cash used in investing activities		(2,805)	(2,724)	(2,788)
Financing Activities
Issuance (repayment) of short-term debt, net		477	(1,591)	295
Issuance (repayment) of affiliated current borrowings, net		(229)	(114)	(51)
Issuance and remarketing of long-term debt		1,500	1,688	1,112
Repayment and repurchase of long-term debt		(681)	(517)	(625)
Common dividend payments		(1,199)		(491)
Other		(11)	(18)	(4)
Net cash provided by (used in) financing activities		(143)	(552)	236
Increase (decrease) in cash, restricted cash and equivalents		13	(7)	3
Cash, restricted cash and equivalents at beginning of year		11	18	15
Cash, restricted cash and equivalents at end of year		24	11	18
Supplemental Cash Flow Information
Interest and related charges, excluding capitalized amounts		458	435	422
Income taxes		362	79	517
Significant noncash investing and financing activities:
Accrued capital expenditures		169	256	169
Dominion Energy Gas Holdings, LLC
Operating Activities
Net income		615	392	457
Adjustments to reconcile net income including noncontrolling interests to net cash provided by operating activities:
Gains on sales of assets		(70)	(50)	(123)
Depreciation, depletion and amortization (including nuclear fuel)		227	204	217
Deferred income taxes and investment tax credits		27	238	163
Other adjustments		(7)	(6)	23
Changes in:
Accounts receivable		(17)	(68)	115
Affiliated receivables and payables		40	88	(105)
Inventories		6	8	(13)
Prepayments		(18)	(6)	99
Accounts payable		(17)	15	(51)
Accrued interest, payroll and taxes		24	42	(11)
Pension and other postretirement benefits		(143)	(141)	(119)
Other operating assets and liabilities		(1)	(68)	(17)
Net cash provided by operating activities		666	648	635
Investing Activities
Plant construction and other property additions (including nuclear fuel)		(778)	(854)	(795)
Proceeds from sale of equity method investment in Iroquois			7
Proceeds from assignment of shale development rights		70	10	79
Other		(19)	(12)	(17)
Net cash used in investing activities		(727)	(849)	(733)
Financing Activities
Issuance of short-term notes		169	69	391
Issuance (repayment) of affiliated current borrowings, net		(100)	23	(289)
Issuance and remarketing of long-term debt			680	700
Repayment and repurchase of long-term debt			(400)
Distribution payments to parent		(15)	(150)	(692)
Other		(6)	(5)	(7)
Net cash provided by (used in) financing activities		48	217	103
Increase (decrease) in cash, restricted cash and equivalents		(13)	16	5
Cash, restricted cash and equivalents at beginning of year		43	27	22
Cash, restricted cash and equivalents at end of year		30	43	27
Supplemental Cash Flow Information
Interest and related charges, excluding capitalized amounts		89	81	70
Income taxes		9	(92)	98
Significant noncash investing and financing activities:
Accrued capital expenditures		$ 38	$ 59	$ 57
[1]	See Note 3 for noncash activities related to the acquisition of Four Brothers and Three Cedars.

Nature of Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	N OTE ATURE OF PERATIONS Dominion Energy, headquartered in Richmond, Virginia, is one of the nation’s largest producers and transporters of energy. Dominion Energy’s operations are conducted through various subsidiaries, including Virginia Power and Dominion Energy Gas. Virginia Power is a regulated public utility that generates, transmits and distributes electricity for sale in Virginia and northeastern North Carolina. Virginia Power is a member of PJM, an RTO, and its electric transmission facilities are integrated into the PJM wholesale electricity markets. All of Virginia Power’s stock is owned by Dominion Energy. Dominion Energy Gas is a holding company that conducts business activities through a regulated interstate natural gas transmission pipeline and underground storage system in the Northeast, mid-Atlantic Dominion Energy’s operations also include the Cove Point LNG import, transport and storage facility in Maryland, an equity investment in Atlantic Coast Pipeline and regulated gas transportation and distribution operations in West Virginia. Dominion Energy’s nonregulated operations include merchant generation, energy marketing and price risk management activities, retail energy marketing operations and an equity investment in Blue Racer. In October 2014, Dominion Energy Midstream launched its initial public offering of 20,125,000 common units representing limited partner interests. At December 31, 2017, Dominion Energy owns the general partner, 50.6% of the common and subordinated units and 37.5% of the convertible preferred interests in Dominion Energy Midstream, which owns a preferred equity interest and the general partner interest in Cove Point, DECG, Dominion Energy Questar Pipeline and a 25.93% noncontrolling partnership interest in Iroquois. The public’s ownership interest in Dominion Energy Midstream is reflected as noncontrolling interest in Dominion Energy’s Consolidated Financial Statements. Dominion Energy manages its daily operations through three primary operating segments: Power Delivery, Power Generation and Gas Infrastructure. Dominion Energy also reports a Corporate and Other segment, which includes its corporate, service company and other functions (including unallocated debt). In addition, Corporate and Other includes specific items attributable to Dominion Energy’s operating segments that are not included in profit measures evaluated by executive management in assessing the segments’ performance or in allocating resources. Virginia Power manages its daily operations through two primary operating segments: Power Delivery and Power Generation. It also reports a Corporate and Other segment that primarily includes specific items attributable to its operating segments that are not included in profit measures evaluated by executive management in assessing the segments’ performance or in allocating resources. Dominion Energy Gas manages its daily operations through one primary operating segment: Gas Infrastructure. It also reports a Corporate and Other segment that primarily includes specific items attributable to its operating segment that are not included in profit measures evaluated by executive management in assessing the segment’s performance or in allocating resources and the effect of certain items recorded at Dominion Energy Gas as a result of Dominion Energy’s basis in the net assets contributed. See Note 25 for further discussion of the Companies’ operating segments.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	N OTE IGNIFICANT CCOUNTING OLICIES General The Companies make certain estimates and assumptions in preparing their Consolidated Financial Statements in accordance with GAAP. These estimates and assumptions affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues, expenses and cash flows for the periods presented. Actual results may differ from those estimates. The Companies’ Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of their respective majority-owned subsidiaries and non-wholly-owned The Companies report certain contracts, instruments and investments at fair value. See Note 6 for further information on fair value measurements. Dominion Energy maintains pension and other postretirement benefit plans. Virginia Power and Dominion Energy Gas participate in certain of these plans. See Note 21 for further information on these plans. Certain amounts in the Companies’ 2017, 2016 and 2015 Consolidated Financial Statements and Notes have been reclassified as a result of the adoption of revised accounting guidance pertaining to certain net periodic pension and other postretirement benefit costs, restricted cash and equivalents and certain distributions from equity method investees. In addition, certain other amounts in the 2016 and 2015 Consolidated Financial Statements and Notes have been reclassified to conform to the 2017 presentation for comparative purposes; however, such reclassifications did not affect the Companies’ net income, total assets, liabilities, equity or cash flows. Amounts disclosed for Dominion Energy are inclusive of Virginia Power and/or Dominion Energy Gas, where applicable. Operating Revenue Operating revenue is recorded on the basis of services rendered, commodities delivered or contracts settled and includes amounts yet to be billed to customers. Dominion Energy and Virginia Power collect sales, consumption and consumer utility taxes and Dominion Energy Gas collects sales taxes; however, these amounts are excluded from revenue. Dominion Energy’s customer receivables at December 31, 2017 and 2016 included $661 million and $631 million, respectively, of accrued unbilled revenue based on estimated amounts of electricity and natural gas delivered but not yet billed to its utility customers. Virginia Power’s customer receivables at December 31, 2017 and 2016 included $400 million and $349 million, respectively, of accrued unbilled revenue based on estimated amounts of electricity delivered but not yet billed to its customers. Dominion Energy Gas’ customer receivables at December 31, 2017 and 2016 included $121 million and $134 million, respectively, of accrued unbilled revenue based on estimated amounts of natural gas delivered but not yet billed to its customers. See Note 9 for amounts attributable to related parties. The primary types of sales and service activities reported as operating revenue for Dominion Energy are as follows: • Regulated electric sales • Nonregulated electric sales • Regulated gas sales • Nonregulated gas sales • Gas transportation and storage • Other revenue The primary types of sales and service activities reported as operating revenue for Virginia Power are as follows: • Regulated electric sales • Other revenue The primary types of sales and service activities reported as operating revenue for Dominion Energy Gas are as follows: • Regulated gas sales • Nonregulated gas sales • Gas transportation and storage • NGL revenue • Other revenue Electric Fuel, Purchased Energy and Purchased Gas-Deferred Where permitted by regulatory authorities, the differences between Dominion Energy’s and Virginia Power’s actual electric fuel and purchased energy expenses and Dominion Energy’s and Dominion Energy Gas’ purchased gas expenses and the related levels of recovery for these expenses in current rates are deferred and matched against recoveries in future periods. The deferral of costs in excess of current period fuel rate recovery is recognized as a regulatory asset, while rate recovery in excess of current period fuel expenses is recognized as a regulatory liability. Of the cost of fuel used in electric generation and energy purchases to serve utility customers, approximately 84% is currently subject to deferred fuel accounting, while substantially all of the remaining amount is subject to recovery through similar mechanisms. Virtually all of Dominion Energy Gas’, Cove Point’s, Questar Gas’ and Hope’s natural gas purchases are either subject to deferral accounting or are recovered from the customer in the same accounting period as the sale. Income Taxes A consolidated federal income tax return is filed for Dominion Energy and its subsidiaries, including Virginia Power and Dominion Energy Gas’ subsidiaries. In addition, where applicable, combined income tax returns for Dominion Energy and its subsidiaries are filed in various states; otherwise, separate state income tax returns are filed. Although Dominion Energy Gas is disregarded for income tax purposes, a provision for income taxes is recognized to reflect the inclusion of its business activities in the tax returns of its parent, Dominion Energy. Virginia Power and Dominion Energy Gas participate in intercompany tax sharing agreements with Dominion Energy and its subsidiaries. Current income taxes are based on taxable income or loss and credits determined on a separate company basis. Under the agreements, if a subsidiary incurs a tax loss or earns a credit, recognition of current income tax benefits is limited to refunds of prior year taxes obtained by the carryback of the net operating loss or credit or to the extent the tax loss or credit is absorbed by the taxable income of other Dominion Energy consolidated group members. Otherwise, the net operating loss or credit is carried forward and is recognized as a deferred tax asset until realized. The 2017 Tax Reform Act includes a broad range of tax reform provisions affecting the Companies, including changes in corporate tax rates and business deductions. The 2017 Tax Reform Act reduces the corporate income tax rate from 35% to 21% for tax years beginning after December 31, 2017. Deferred tax assets and liabilities are classified as noncurrent in the Consolidated Balance Sheets and measured at the enacted tax rate expected to apply when temporary differences are realized or settled. Thus, at the date of enactment, federal deferred taxes were remeasured based upon the new 21% tax rate. The total effect of tax rate changes on deferred tax balances is recorded as a component of the income tax provision related to continuing operations for the period in which the law is enacted, even if the assets and liabilities relate to other components of the financial statements, such as items of accumulated other comprehensive income. For Dominion Energy subsidiaries that are not rate-regulated utilities, existing deferred income tax assets or liabilities were adjusted for the reduction in the corporate income tax rate and allocated to continuing operations. Dominion Energy’s rate-regulated utility subsidiaries likewise are required to adjust deferred income tax assets and liabilities for the change in income tax rates. However, if it is probable that the effect of the change in income tax rates will be recovered or refunded in future rates, the regulated utility recorded a regulatory asset or liability instead of an increase or decrease to deferred income tax expense. Accounting for income taxes involves an asset and liability approach. Deferred income tax assets and liabilities are provided, representing future effects on income taxes for temporary differences between the bases of assets and liabilities for financial reporting and tax purposes. Accordingly, deferred taxes are recognized for the future consequences of different treatments used for the reporting of transactions in financial accounting and income tax returns. The Companies establish a valuation allowance when it is more-likely-than-not The Companies recognize positions taken, or expected to be taken, in income tax returns that are more-likely-than-not If it is not more-likely-than-not The Companies recognize interest on underpayments and overpayments of income taxes in interest expense and other income, respectively. Penalties are also recognized in other income. Dominion Energy and Virginia Power both recognized interest income of $11 million in 2017. Dominion Energy Gas’ interest was immaterial in 2017. Interest for the Companies was immaterial in 2016 and 2015. Dominion Energy’s, Virginia Power’s and Dominion Energy Gas’ penalties were immaterial in 2017, 2016 and 2015. At December 31, 2017, Virginia Power had an income tax-related In addition, Virginia Power’s Consolidated Balance Sheet at December 31, 2017 included $1 million of noncurrent federal income taxes receivable, less than $1 million of state income taxes receivable and $1 million of noncurrent state income taxes receivable. Dominion Energy Gas’ Consolidated Balance Sheet at December 31, 2017 included $14 million of state income taxes receivable. At December 31, 2016, Virginia Power had an income tax-related In addition, Virginia Power’s Consolidated Balance Sheet at December 31, 2016 included $2 million of noncurrent federal income taxes payable, $6 million of state income taxes receivable and $13 million of noncurrent state income taxes receivable. Dominion Energy Gas’ Consolidated Balance Sheet at December 31, 2016 included $1 million of noncurrent federal income taxes payable, $1 million of state income taxes receivable and $7 million of noncurrent state income taxes payable. Investment tax credits are recognized by nonregulated operations in the year qualifying property is placed in service. For regulated operations, investment tax credits are deferred and amortized over the service lives of the properties giving rise to the credits. Production tax credits are recognized as energy is generated and sold. Cash, Restricted Cash and Equivalents Current banking arrangements generally do not require checks to be funded until they are presented for payment. The following table illustrates the checks outstanding but not yet presented for payment and recorded in accounts payable for the Companies: Year Ended December 31, 2017 2016 (millions) Dominion Energy $ 30 $ 24 Virginia Power 17 11 Dominion Energy Gas 7 9 R ESTRICTED ASH AND QUIVALENTS The Companies hold restricted cash and equivalent balances that primarily consist of amounts held for certain customer deposits, future debt payments on SBL Holdco and Dominion Solar Projects III, Inc.’s term loan agreements and a distribution reserve at Cove Point. Upon adoption of revised accounting guidance in January 2018, restricted cash and equivalents are included within the Companies’ Consolidated Statements of Cash Flows, with the change in balance no longer considered a separate investing activity. The guidance required retrospective application which resulted in adjustments to other cash provided by (used in) investing activities presented within Dominion Energy, Virginia Power and Dominion Energy Gas’ Consolidated Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015, which were previously reported as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy $ 29 $ 47 $ (71 ) Virginia Power (51 ) (33 ) (87 ) Dominion Energy Gas (23 ) (18 ) (11 ) The following table provides a reconciliation of the total cash, restricted cash and equivalents reported within the Companies’ Consolidated Balance Sheets to the corresponding amounts reported within the Companies’ Consolidated Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015: Cash, Restricted Cash and Equivalents at At December 31, 2017 2016 2015 2014 (millions) Dominion Energy Cash and cash equivalents $ 120 $ 261 $ 607 $ 318 Restricted cash and equivalents (1) 65 61 25 19 Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 185 $ 322 $ 632 $ 337 Virginia Power Cash and cash equivalents $ 14 $ 11 $ 18 $ 15 Restricted cash and equivalents (1) 10 — — — Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 24 $ 11 $ 18 $ 15 Dominion Energy Gas Cash and cash equivalents $ 4 $ 23 $ 13 $ 9 Restricted cash and equivalents (1) 26 20 14 13 Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 30 $ 43 $ 27 $ 22 (1) Restricted cash and equivalent balances are presented within other current assets in the Companies’ Consolidated Balance Sheets. D ISTRIBUTIONS FROM QUITY ETHOD NVESTEES Dominion Energy and Dominion Energy Gas each hold investments that are accounted for under the equity method of accounting. Effective January 2018, Dominion Energy and Dominion Energy Gas classify distributions from equity method investees as either cash flows from operating activities or cash flows from investing activities in the Consolidated Statements of Cash Flows according to the nature of the distribution. Dis-tributions received are classified on the basis of the nature of the activity of the investee that generated the distribution as either a return on investment (classified as cash flows from operating activities) or a return of an investment (classified as cash flows from investing activities) when such information is available to Dominion Energy and Dominion Energy Gas. Previously, distributions were determined to be either a return on an investment or return of an investment based on a cumulative earnings approach whereby any distributions received in excess of earnings were considered to be a return of an investment. Dominion Energy and Dominion Energy Gas have applied this approach on a retrospective basis. As a result distributions from equity method investees were reclassified within the Consolidated Statements of Cash Flows between distributions from equity method affiliates and other cash used in investing activities at Dominion Energy and Dominion Energy Gas, respectively, to other adjustments from operating activities for both Dominion Energy and Dominion Energy Gas, which were previously reported as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy $ (37 ) $ (108 ) $ (42 ) Dominion Energy Gas (9 ) (6 ) 16 For purposes of the Consolidated Statements of Cash Flows, cash, restricted cash and equivalents include cash on hand, cash in banks and temporary investments purchased with an original maturity of three months or less. Derivative Instruments Dominion Energy uses derivative instruments such as physical and financial forwards, futures, swaps, options and FTRs to manage the commodity, interest rate and foreign currency exchange rate risks of its business operations. Virginia Power uses derivative instruments such as physical and financial forwards, futures, swaps, options and FTRs to manage commodity and interest rate risks. Dominion Energy Gas uses derivative instruments such as physical and financial forwards, futures and swaps to manage commodity, interest rate and foreign currency exchange rate risks. All derivatives, except those for which an exception applies, are required to be reported in the Consolidated Balance Sheets at fair value. Derivative contracts representing unrealized gain positions and purchased options are reported as derivative assets. Derivative contracts representing unrealized losses and options sold are reported as derivative liabilities. One of the exceptions to fair value accounting, normal purchases and normal sales, may be elected when the contract satisfies certain criteria, including a requirement that physical delivery of the underlying commodity is probable. Expenses and revenues resulting from deliveries under normal purchase contracts and normal sales contracts, respectively, are included in earnings at the time of contract performance. The Companies do not offset amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral against amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. Dominion Energy had margin assets of $92 million and $82 million associated with cash collateral at December 31, 2017 and 2016, respectively. Dominion Energy’s margin liabilities associated with cash collateral at December 31, 2017 or 2016 were immaterial. Virginia Power had margin assets of $23 million and $2 million associated with cash collateral at December 31, 2017 and 2016, respectively. Virginia Power’s margin liabilities associated with cash collateral were immaterial at December 31, 2017 and 2016. Dominion Energy Gas’ margin assets and liabilities associated with cash collateral were immaterial at December 31, 2017 and 2016. See Note 7 for further information about derivatives. To manage price risk, the Companies hold certain derivative instruments that are not designated as hedges for accounting purposes. However, to the extent the Companies do not hold offsetting positions for such derivatives, they believe these instruments represent economic hedges that mitigate their exposure to fluctuations in commodity prices. All income statement activity, including amounts realized upon settlement, is presented in operating revenue, operating expenses, interest and related charges or other income based on the nature of the underlying risk. Changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities for jurisdictions subject to cost-based rate regulation. Realized gains or losses on the derivative instruments are generally recognized when the related transactions impact earnings. D ERIVATIVE NSTRUMENTS ESIGNATED AS EDGING NSTRUMENTS The Companies designate a portion of their derivative instruments as either cash flow or fair value hedges for accounting purposes. For all derivatives designated as hedges, the Companies formally document the relationship between the hedging instrument and the hedged item, as well as the risk management objective and the strategy for using the hedging instrument. The Companies assess whether the hedging relationship between the derivative and the hedged item is highly effective at offsetting changes in cash flows or fair values both at the inception of the hedging relationship and on an ongoing basis. Any change in the fair value of the derivative that is not effective at offsetting changes in the cash flows or fair values of the hedged item is recognized currently in earnings. Also, the Companies may elect to exclude certain gains or losses on hedging instruments from the assessment of hedge effectiveness, such as gains or losses attributable to changes in the time value of options or changes in the difference between spot prices and forward prices, thus requiring that such changes be recorded currently in earnings. Hedge accounting is discontinued prospectively for derivatives that cease to be highly effective hedges. For derivative instruments that are accounted for as fair value hedges or cash flow hedges, the cash flows from the derivatives and from the related hedged items are classified in operating cash flows. Cash Flow Hedges Dominion Energy entered into interest rate derivative instruments to hedge its forecasted interest payments related to planned debt issuances in 2014. These interest rate derivatives were designated by Dominion Energy as cash flow hedges prior to the formation of Dominion Energy Gas. For the purposes of the Dominion Energy Gas financial statements, the derivative balances, AOCI balance, and any income statement impact related to these interest rate derivative instruments entered into by Dominion Energy have been, and will continue to be, included in the Dominion Energy Gas’ Consolidated Financial Statements as the forecasted interest payments related to the debt issuances now occur at Dominion Energy Gas. Fair Value Hedges Property, Plant and Equipment Property, plant and equipment is recorded at lower of original cost or fair value, if impaired. Capitalized costs include labor, materials and other direct and indirect costs such as asset retirement costs, capitalized interest and, for certain operations subject to cost-of-service In 2017, 2016 and 2015, Dominion Energy capitalized interest costs and AFUDC to property, plant and equipment of $236 million, $159 million and $100 million, respectively. In 2017, 2016 and 2015, Virginia Power capitalized AFUDC to property, plant and equipment of $37 million, $21 million and $30 million, respectively. In 2017, 2016 and 2015, Dominion Energy Gas capitalized AFUDC to property, plant and equipment of $25 million, $8 million and $1 million, respectively. Under Virginia law, certain Virginia jurisdictional projects qualify for current recovery of AFUDC through rate adjustment clauses. AFUDC on these projects is calculated and recorded as a regulatory asset and is not capitalized to property, plant and equipment. In 2017, 2016 and 2015, Virginia Power recorded $22 million, $31 million and $19 million of AFUDC related to these projects, respectively. For property subject to cost-of-service cost-of-service plant-in-service For property that is not subject to cost-of-service Depreciation of property, plant and equipment is computed on the straight-line method based on projected service lives. The Companies’ average composite depreciation rates on utility property, plant and equipment are as follows: Year Ended December 31, 2017 2016 2015 (percent) Dominion Energy Generation 2.94 2.83 2.78 Transmission 2.55 2.47 2.42 Distribution 3.00 3.02 3.11 Storage 2.48 2.29 2.42 Gas gathering and processing 2.21 2.66 3.19 General and other 4.89 4.12 3.67 Virginia Power Generation 2.94 2.83 2.78 Transmission 2.54 2.36 2.33 Distribution 3.32 3.32 3.33 General and other 4.68 3.49 3.40 Dominion Energy Gas Transmission 2.40 2.43 2.46 Distribution 2.42 2.55 2.45 Storage 2.45 2.19 2.44 Gas gathering and processing 2.42 2.58 3.20 General and other 4.96 4.54 4.72 In the first quarter of 2017, Virginia Power revised the depreciation rates for its assets to reflect the results of a new depreciation study. This change resulted in an increase in annual depreciation expense of $40 million ($25 million after-tax) after-tax) Capitalized costs of development wells and leaseholds are amortized on a field-by-field unit-of-production Dominion Energy’s nonutility property, plant and equipment is depreciated using the straight-line method over the following estimated useful lives: Asset Estimated Useful Lives Merchant generation-nuclear 44 years Merchant generation-other 15-40 years Nonutility gas gathering and processing 3-50 General and other 5-59 Depreciation and amortization related to Virginia Power’s and Dominion Energy Gas’ nonutility property, plant and equipment and exploration and production properties was immaterial for the years ended December 31, 2017, 2016 and 2015, except for Dominion Energy Gas’ nonutility gas gathering and processing properties which are depreciated using the straight-line method over estimated useful lives between 10 and 50 years. Nuclear fuel used in electric generation is amortized over its estimated service life on a units-of-production Long-Lived and Intangible Assets The Companies perform an evaluation for impairment whenever events or changes in circumstances indicate that the carrying amount of long-lived assets or intangible assets with finite lives may not be recoverable. A long-lived or intangible asset is written down to fair value if the sum of its expected future undiscounted cash flows is less than its carrying amount. Intangible assets with finite lives are amortized over their estimated useful lives. Regulatory Assets and Liabilities The accounting for Dominion Energy’s and Dominion Energy Gas’ regulated gas and Virginia Power’s regulated electric operations differs from the accounting for nonregulated operations in that they are required to reflect the effect of rate regulation in their Consolidated Financial Statements. For regulated businesses subject to federal or state cost-of-service The Companies evaluate whether or not recovery of their regulatory assets through future rates is probable and make various assumptions in their analyses. The expectations of future recovery are generally based on orders issued by regulatory commissions, legislation or historical experience, as well as discussions with applicable regulatory authorities and legal counsel. If recovery of a regulatory asset is determined to be less than probable, it will be written off in the period such assessment is made. Asset Retirement Obligations The Companies recognize AROs at fair value as incurred or when sufficient information becomes available to determine a reasonable estimate of the fair value of future retirement activities to be performed, for which a legal obligation exists. These amounts are generally capitalized as costs of the related tangible long-lived assets. Since relevant market information is not available, fair value is estimated using discounted cash flow analyses. Quarterly, the Companies assess their AROs to determine if circumstances indicate that estimates of the amounts or timing of future cash flows associated with retirement activities have changed. AROs are adjusted when significant changes in the amounts or timing of future cash flows are identified. Dominion Energy and Dominion Energy Gas report accretion of AROs and depreciation on asset retirement costs associated with their natural gas pipeline and storage well assets as an adjustment to the related regulatory liabilities when revenue is recoverable from customers for AROs. Virginia Power reports accretion of AROs and depreciation on asset retirement costs associated with decommissioning its nuclear power stations as an adjustment to the regulatory liability for certain jurisdictions. Additionally, Virginia Power reports accretion of AROs and depreciation on asset retirement costs associated with certain rider and prospective rider projects as an adjustment to the regulatory asset for certain jurisdictions. Accretion of all other AROs and depreciation of all other asset retirement costs are reported in other operations and maintenance expense and depreciation expense, respectively, in the Consolidated Statements of Income. Debt Issuance Costs The Companies defer and amortize debt issuance costs and debt premiums or discounts over the expected lives of the respective debt issues, considering maturity dates and, if applicable, redemption rights held by others. Deferred debt issuance costs are recorded as a reduction in long-term debt in the Consolidated Balance Sheets. Amortization of the issuance costs is reported as interest expense. Unamortized costs associated with redemptions of debt securities prior to stated maturity dates are generally recognized and recorded in interest expense immediately. As permitted by regulatory authorities, gains or losses resulting from the refinancing of debt allocable to utility operations subject to cost-based rate regulation are deferred and amortized over the lives of the new issuances. Investments M ARKETABLE QUITY AND EBT ECURITIES Dominion Energy accounts for and classifies investments in marketable equity and debt securities as trading or available-for-sale available-for-sale • Trading securities • Available-for-sale available-for-sale after-tax. In determining realized gains and losses for marketable equity and debt securities, the cost basis of the security is based on the specific identification method. N ON -M ARKETABLE NVESTMENTS The Companies account for illiquid and privately held securities for which market prices or quotations are not readily available under either the equity or cost method. Non-marketable • Equity method investments • Cost method investments O THER HAN EMPORARY MPAIRMENT The Companies periodically review their investments to determine whether a decline in fair value should be considered other-than-temporary. If a decline in fair value of any security is determined to be other-than-temporary, the security is written down to its fair value at the end of the reporting period. Decommissioning Trust Investments—Special Considerations • The recognition provisions of the FASB’s other-than-temporary impairment guidance apply only to debt securities classified as available-for-sale held-to-maturity, • Debt Securities more-likely-than-not non-performance • Equity securities and other investments day-to-day non-marketable Inventories Materials and supplies and fossil fuel inventories are valued primarily using the weighted-average cost method. Stored gas inventory is valued using the weighted-average cost method, except for East Ohio gas distribution operations, which are valued using the LIFO method. Under the LIFO method, current stored gas inventory was valued at $9 million and $13 million at December 31, 2017 and December 31, 2016, respectively. Based on the average price of gas purchased during 2017 and 2016, the cost of replacing the current portion of stored gas inventory exceeded the amount stated on a LIFO basis by $79 million and $55 million, respectively. Gas Imbalances Natural gas imbalances occur when the physical amount of natural gas delivered from, or received by, a pipeline system or storage facility differs from the contractual amount of natural gas delivered or received. Dominion Energy and Dominion Energy Gas value these imbalances due to, or from, shippers and operators at an appropriate index price at period end, subject to the terms of its tariff for regulated entities. Imbalances are primarily settled in-kind. Goodwill Dominion Energy and Dominion Energy Gas evaluate goodwill for impairment annually as of April 1 and whenever an event occurs or circumstances change in the interim that would more-likely-than-not New Accounting Standards R EVENUE ECOGNITION In May 2014, the FASB issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this revised accounting guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consid-eration to which the entity expects to be entitled in exchange for those goods or services. The amendments in this update also require disclosure of the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. For the Companies, the revised accounting guidance is effective for interim and annual periods beginning January 1, 2018. The Companies have completed their evaluations of the impact of this guidance and expect no significant impact on their results of operations. However, the Companies will have offsetting increases in operating revenues and other energy-related purchases for noncash consideration related to NGLs received in consideration for performing processing and fractionation services and offsetting decreases in operating revenues and purchased gas for fuel retained to offset costs on certain transportation and storage arrangements. The Companies will apply the standard using the modified retrospective method as opposed to the full retrospective method. F INANCIAL NSTRUMENTS In January 2016, the FASB issued revised accounting guidance for the recognition, measurement, presentation and disclosure of financial instruments. In accordance with the guidance effective January 2018, Dominion Energy and Virginia Power will no longer classify equity securities as trading or available-for-sale Upon adoption of this guidance for equity securities held at January 1, 2018, Dominion Energy and Virginia Power recorded the cumulative-effect of a change in accounting principle to reclassify net unrealized gains from AOCI to retained earnings and to recognize equity securities previously categorized as cost method investments at fair value in nuclear decommissioning trust funds in the Consolidated Balance Sheets and a cumulative-effect adjustment to retained earnings. Dominion Energy and Virginia Power reclassified approximately $1.1 billion ($734 million after-tax) after-tax) after-tax), L EASES In February 2016, the FASB issued revised accounting guidance for the recognition, measurement, presentation and disclosure of leasing arrangements. The update requires that a liability and corresponding right-of-use The guidance is effective for the Companies’ interim and annual reportin

Acquisitions and Dispositions

Acquisitions and Dispositions	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Acquisitions and Dispositions	N OTE CQUISITIONS AND ISPOSITIONS D OMINION NERGY Proposed Acquisition of SCANA Under the terms of the SCANA Merger Agreement announced in January 2018, Dominion Energy has agreed to issue 0.6690 shares of Dominion Energy common stock for each share of SCANA common stock upon closing. In addition, Dominion Energy will provide the financial support for SCE&G to make a $1.3 billion up-front, one-time The transaction requires approval of SCANA’s shareholders, FERC and the NRC and clearance from the Federal Trade Commission under the Hart-Scott-Rodino Act. In February 2018, the Federal Trade Commission granted early termination of the waiting period under the Hart-Scott-Rodino Act. In January 2018, SCANA and Dominion Energy filed for review and approval, as required, from the South Carolina Commission, the North Carolina Commission, the Georgia Public Service Commission and the NRC. Dominion Energy is not required to accept an order by the South Carolina Commission approving Dominion Energy’s merger with SCANA if such order contains any material change to the terms, conditions or undertakings set forth in the cost recovery plan related to the V.C. Summer Units 2 and 3 new nuclear development project or any significant changes to the economic value of the cost recovery plan. In addition, the SCANA Merger Agreement provides that Dominion Energy will have the right to refuse to close the merger if there shall have occurred any substantive change in the Base Load Review Act or other laws governing South Carolina public utilities which has or would reasonably be expected to have an adverse effect on SCE&G. The SCANA Merger Agreement contains certain termination rights for both Dominion Energy and SCANA, and provides that, upon termination of the SCANA Combination under specified circumstances, Dominion Energy would be required to pay a termination fee of $280 million to SCANA and SCANA would be required to pay Dominion Energy a termination fee of $240 million. Subject to receipt of SCANA shareholder and any required regulatory approvals and meeting closing conditions, Dominion Energy targets closing by the end of 2018. Acquisition of Dominion Energy Questar In September 2016, Dominion Energy completed the Dominion Energy Questar Combination and Dominion Energy Questar, a Rockies-based integrated natural gas company, became a wholly-owned subsidiary of Dominion Energy. Dominion Energy Questar included Questar Gas, Wexpro and Dominion Energy Questar Pipeline at closing. Questar Gas has regulated gas distribution operations in Utah, southwestern Wyoming and southeastern Idaho. Wexpro develops and produces natural gas from reserves supplied to Questar Gas under a cost-of-service In accordance with the terms of the Dominion Energy Questar Combination, at closing, each share of issued and outstanding Dominion Energy Questar common stock was converted into the right to receive $25.00 per share in cash. The total consideration was $4.4 billion based on 175.5 million shares of Dominion Energy Questar outstanding at closing. Dominion Energy financed the Dominion Energy Questar Combination through the: (1) August 2016 issuance of $1.4 billion of 2016 Equity Units, (2) August 2016 issuance of $1.3 billion of senior notes, (3) September 2016 borrowing of $1.2 billion under a term loan agreement and (4) $500 million of the proceeds from the April 2016 issuance of common stock. See Notes 17 and 19 for more information. P URCHASE RICE LLOCATION Dominion Energy Questar’s assets acquired and liabilities assumed were measured at estimated fair value at the closing date and are included in the Gas Infrastructure operating segment. The majority of operations acquired are subject to the rate-setting authority of FERC, as well as the Utah Commission and/or the Wyoming Commission and therefore are accounted for pursuant to ASC 980, Regulated Operations The fair value of Dominion Energy Questar’s assets acquired and liabilities assumed that are not subject to the rate-setting provisions discussed above was determined using the income approach. In addition, the fair value of Dominion Energy Questar’s 50% interest in White River Hub, accounted for under the equity method, was determined using the market approach and income approach. The valuations are considered Level 3 fair value measurements due to the use of significant judgmental and unobservable inputs, including projected timing and amount of future cash flows and discount rates reflecting risk inherent in the future cash flows and future market prices. The excess of the purchase price over the estimated fair values of the assets acquired and liabilities assumed was recognized as goodwill at the closing date. The goodwill reflects the value associated with enhancing Dominion Energy’s regulated portfolio of businesses, including the expected increase in demand for low-carbon, gas-fired The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at closing which reflects the following adjustments from the preliminary valuation recog-nized during the measurement period. During the fourth quarter of 2016, certain modifications were made to preliminary valuation amounts for acquired property, plant and equipment, current liabilities, and deferred income taxes, resulting in a $6 million net decrease to goodwill, which related primarily to the sale of Questar Fueling Company in December 2016 as further described in the Sale of Questar Fueling Company Amount (millions) Total current assets $ 224 Investments (1) 58 Property, plant and equipment (2) 4,131 Goodwill 3,111 Total deferred charges and other assets, excluding goodwill 75 Total Assets 7,599 Total current liabilities (3) 793 Long-term debt (4) 963 Deferred income taxes 807 Regulatory liabilities 259 Asset retirement obligations 160 Other deferred credits and other liabilities 220 Total Liabilities 3,202 Total purchase price 4,397 (1) Includes $40 million for an equity method investment in White River Hub. The fair value adjustment on the equity method investment in White River Hub is considered to be equity method goodwill and is not amortized. (2) Nonregulated property, plant and equipment, excluding land, will be depreciated over remaining useful lives primarily ranging from 9 to 18 years. (3) Includes $301 million of short-term debt, of which no amounts remain outstanding at December 31, 2017, as well as a $250 million variable interest rate term loan due in August 2017 that was paid in July 2017. (4) Unsecured senior and medium-term notes with maturities which range from 2017 to 2048 and bear interest at rates from 2.98% to 7.20%. R EGULATORY ATTERS The transaction required approval of Dominion Energy Questar’s shareholders, clearance from the Federal Trade Commission under the Hart-Scott-Rodino Act and approval from both the Utah Commission and the Wyoming Commission. In February 2016, the Federal Trade Commission granted antitrust approval of the Dominion Energy Questar Combination under the Hart-Scott-Rodino Act. In May 2016, Dominion Energy Questar’s shareholders voted to approve the Dominion Energy Questar Combination. In August 2016 and September 2016, approvals were granted by the Utah Commission and the Wyoming Commission, respectively. Information regarding the transaction was also provided to the Idaho Commission, who acknowledged the Dominion Energy Questar Combination in October 2016, and directed Dominion Energy Questar to notify the Idaho Commission when it makes filings with the Utah Commission. With the approval of the Dominion Energy Questar Combination in Utah and Wyoming, Dominion Energy agreed to the following: • Contribution of $75 million to Dominion Energy Questar’s qualified and non-qualified • Increasing Dominion Energy Questar’s historical level of corporate contributions to charities by $1 million per year for at least five years. • Withdrawal of Questar Gas’ general rate case filed in July 2016 with the Utah Commission and agreement to not file a general rate case with the Utah Commission to adjust its base distribution non-gas R ESULTS OF PERATIONS AND RO ORMA NFORMATION The impact of the Dominion Energy Questar Combination on Dominion Energy’s operating revenue and net income attributable to Dominion Energy in the Consolidated Statements of Income for the twelve months ended December 31, 2016 was an increase of $379 million and $73 million, respectively. Dominion Energy incurred transaction and transition costs in 2017 and 2016, of which $26 million and $58 million was recorded in other operations and maintenance expense, respectively, and $16 million was recorded in interest and related charges in 2016 in Dominion Energy’s Consolidated Statements of Income. These costs consist of the amortization of financing costs, the charitable contribution commitment described above, employee-related expenses, professional fees, and other miscellaneous costs. The following unaudited pro forma financial information reflects the consolidated results of operations of Dominion Energy assuming the Dominion Energy Questar Combination had taken place on January 1, 2015. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved or the future consolidated results of operations of the combined company. Twelve Months Ended December 31, 2016 (1) 2015 (millions, except EPS) Operating Revenue $12,497 $12,818 Net income attributable to Dominion Energy 2,300 2,108 Earnings Per Common Share – Basic $ 3.73 $ 3.56 Earnings Per Common Share – Diluted $ 3.73 $ 3.55 (1) Amounts include adjustments for non-recurring C ONTRIBUTION OF OMINION NERGY UESTAR IPELINE TO OMINION NERGY IDSTREAM In October 2016, Dominion Energy entered into the Contribution Agreement under which Dominion Energy contributed Dominion Energy Questar Pipeline to Dominion Energy Midstream. Upon closing of the agreement on December 1, 2016, Dominion Energy Midstream became the owner of all of the issued and outstanding membership interests of Dominion Energy Questar Pipeline in exchange for consideration consisting of Dominion Energy Midstream common and convertible preferred units with a combined value of $467 million and cash payment of $823 million, $300 million of which is considered a debt-financed distribution, for a total of $1.3 billion. In addition, under the terms of the Contribution Agreement, Dominion Energy Midstream repurchased 6,656,839 common units from Dominion Energy, and repaid its $301 million promissory note to Dominion Energy in December 2016. The cash proceeds from these transactions were utilized in December 2016 to repay the $1.2 billion term loan agreement borrowed in September 2016. Since Dominion Energy consolidates Dominion Energy Midstream for financial reporting purposes, the transactions associated with the Contribution Agreement were eliminated upon consolidation. See Note 5 for the tax impacts of the transactions. S ALE OF UESTAR UELING OMPANY In December 2016, Dominion Energy completed the sale of Questar Fueling Company. The proceeds from the sale were $28 million, net of transaction costs. No gain or loss was recorded in Dominion Energy’s Consolidated Statements of Income, as the sale resulted in measurement period adjustments to the net assets acquired of Dominion Energy Questar. See the Purchase Price Allocation Wholly-Owned Merchant Solar Projects A CQUISITIONS The following table presents significant completed acquisitions of wholly-owned merchant solar projects by Dominion Energy. Completed Acquisition Seller Number of Project Project Name(s) Initial (1) Project (2) Date of Commercial MW April 2015 EC&R NA Solar PV, LLC 1 California Alamo $ 66 $ 66 May 2015 20 April 2015 EDF Renewable Development, Inc. 3 California Cottonwood (3) 106 106 May 2015 24 June 2015 EDF Renewable Development, Inc. 1 California Catalina 2 68 68 July 2015 18 July 2015 SunPeak Solar, LLC 1 California Imperial Valley 2 42 71 August 2015 20 November 2015 EC&R NA Solar PV, LLC 1 California Maricopa West 65 65 December 2015 20 November 2015 Community Energy Solar, LLC 1 Virginia Amazon Solar Farm 34 212 October 2016 80 February 2017 Community Energy Solar, LLC 1 Virginia Amazon Solar Farm 29 205 December 2017 100 March 2017 Solar Frontier Americas Holding LLC 1 (4) California Midway II 77 78 June 2017 30 May 2017 Cypress Creek Renewables, LLC 1 North IS37 154 160 June 2017 79 June 2017 Hecate Energy Virginia C&C LLC 1 Virginia Clarke County 16 16 August 2017 10 June 2017 Strata Solar Development, LLC/Moorings Farm 2 Holdco, LLC 2 North Fremont, Moorings 2 20 20 November 2017 10 September 2017 Hecate Energy Virginia C&C LLC 1 Virginia Cherrydale 40 41 November 2017 20 October 2017 Strata Solar Development, LLC 2 North Clipperton, Pikeville 20 21 November 2017 10 (1) The purchase price was primarily allocated to Property, Plant and Equipment. (2) Includes acquisition cost. (3) One of the projects, Marin Carport, began commercial operations in 2016. (4) In April 2017, Dominion Energy discontinued efforts on the acquisition of the additional 20 MW solar project from Solar Frontier Americas Holding LLC. In addition during 2016, Dominion Energy acquired 100% of the equity interests of seven solar projects in Virginia, North Carolina and South Carolina for an aggregate purchase price of $32 million, all of which was allocated to property, plant and equipment. The projects cost $421 million in total, including initial acquisition costs, and generate 221 MW combined. One of the projects commenced commercial operations in 2016 and the remaining projects commenced commercial operations in 2017. Long-term power purchase, interconnection and operation and maintenance agreements have been executed for all of the projects described above. These projects are included in the Power Generation operating segment. Dominion Energy has claimed or will claim federal investment tax credits on these solar projects. S ALE OF NTEREST IN ERCHANT OLAR ROJECTS In September 2015, Dominion Energy signed an agreement to sell a noncontrolling interest (consisting of 33% of the equity interests) in all of its then-currently wholly-owned merchant solar projects, 24 solar projects totaling 425 MW, to SunEdison, including certain projects in the table above. In December 2015, the sale of interest in 15 of the solar projects closed for $184 million with the sale of interest in the remaining projects completed in January 2016 for $117 million. Upon closing, SunEdison sold its interest in these projects to Terra Nova Renewable Partners. Terra Nova Renewable Partners has a future option to buy all or a portion of Dominion Energy’s remaining 67% ownership in the projects upon the occurrence of certain events, none of which are expected to occur in 2018. Non-Wholly-Owned A CQUISITIONS OF OUR ROTHERS AND HREE EDARS In June 2015, Dominion Energy acquired 50% of the units in Four Brothers from SunEdison for $64 million of consideration, consisting of $2 million in cash and a $62 million payable. Dominion Energy had no remaining obligation related to this payable at December 31, 2016. Four Brothers operates four solar projects located in Utah, which produce and sell electricity and renewable energy credits. The facilities began commercial operations during the third quarter of 2016, generating 320 MW, at a cost of approximately $670 million. In September 2015, Dominion Energy acquired 50% of the units in Three Cedars from SunEdison for $43 million of consideration, consisting of $6 million in cash and a $37 million payable. There was a $2 million payable included in other current liabilities in Dominion Energy’s Consolidated Balance Sheets at December 31, 2016. Dominion has no remaining obligation related to this payable at December 31, 2017. Three Cedars operates three solar projects located in Utah, which produce and sell electricity and renewable energy credits. The facilities began commercial operations during the third quarter of 2016, generating 210 MW, at a cost of approximately $450 million. The Four Brothers and Three Cedars facilities operate under long-term power purchase, interconnection and operation and maintenance agreements. Dominion Energy claimed 99% of the federal investment tax credits on the projects. Dominion Energy owns 50% of the voting interests in Four Brothers and Three Cedars and has a controlling financial interest over the entities through its rights to control operations. The allocation of the $64 million purchase price for Four Brothers resulted in $89 million of property, plant and equipment and $25 million of noncontrolling interest. The allocation of the $43 million purchase price for Three Cedars resulted in $65 million of property, plant and equipment and $22 million of noncontrolling interest. The noncontrolling interest for each entity was measured at fair value using the discounted cash flow method, with the primary components of the valuation being future cash flows (both incoming and outgoing) and the discount rate. Dominion Energy determined its discount rate based on the cost of capital a utility-scale investor would expect, as well as the cost of capital an individual project developer could achieve via a combination of nonrecourse project financing and outside equity partners. The acquired assets of Four Brothers and Three Cedars are included in the Power Generation operating segment. Dominion Energy has assumed the majority of the agreements to provide administrative and support services in connection with operations and maintenance of the facilities and technical management services of the solar facilities. Costs related to services to be provided under these agreements were immaterial for the years ended December 31, 2017, 2016 and 2015. In November 2016, NRG acquired the 50% of units in Four Brothers and Three Cedars previously held by SunEdison. Subsequent to Dominion Energy’s acquisition of Four Brothers and Three Cedars, SunEdison and NRG made contributions to Four Brothers and Three Cedars of $301 million in aggregate through December 31, 2017, which are reflected as noncontrolling interests in the Consolidated Balance Sheets. Dominion Energy Midstream Acquisition of Interest in Iroquois In September 2015, Dominion Energy Midstream acquired from NG and NJNR a 25.93% noncontrolling partnership interest in Iroquois, which owns and operates a 416-mile, Acquisition of DECG In January 2015, Dominion Energy completed the acquisition of 100% of the equity interests of DECG from SCANA for $497 million in cash, as adjusted for working capital. DECG owns and operates nearly 1,500 miles of FERC-regulated interstate natural gas pipeline in South Carolina and southeastern Georgia. This acquisition supports Dominion Energy’s natural gas expansion into the southeastern U.S. The allocation of the purchase price resulted in $277 million of net property, plant and equipment, $250 million of goodwill, of which approximately $225 million is expected to be deductible for income tax purposes, and $38 million of regulatory liabilities. The goodwill reflects the value associated with enhancing Dominion Energy’s regulated gas position, economic value attributable to future expansion projects as well as increased opportunities for synergies. The acquired assets of DECG are included in the Gas Infrastructure operating segment. On March 24, 2015, DECG converted to a limited liability company under the laws of South Carolina and changed its name from Carolina Gas Transmission Corporation to DECG. On April 1, 2015, Dominion Energy contributed 100% of the issued and outstanding membership interests of DECG to Dominion Energy Midstream in exchange for total consideration of $501 million, as adjusted for working capital. Total consideration to Dominion Energy consisted of the issuance of a two-year, V IRGINIA OWER Acquisition of Solar Projects In December 2015, Virginia Power completed the acquisition of 100% of a solar development project in North Carolina from Morgans Corner for $47 million, all of which was allocated to property, plant and equipment. The project was placed into service in December 2015 with a total cost of $49 million, including the initial acquisition cost. The project generates 20 MW. The output generated by the project is used to meet a ten-year non-jurisdictional D OMINION NERGY AND OMINION NERGY AS Blue Racer See Note 9 for a discussion of transactions related to Blue Racer.

Operating Revenue

Operating Revenue	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Operating Revenue	N OTE PERATING EVENUE The Companies’ operating revenue consists of the following: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy Electric sales: Regulated $ 7,383 $ 7,348 $ 7,482 Nonregulated 1,429 1,519 1,488 Gas sales: Regulated 1,067 500 218 Nonregulated 457 354 471 Gas transportation and storage 1,786 1,636 1,616 Other 464 380 408 Total operating revenue $ 12,586 $ 11,737 $ 11,683 Virginia Power Regulated electric sales $ 7,383 $ 7,348 $ 7,482 Other 173 240 140 Total operating revenue $ 7,556 $ 7,588 $ 7,622 Dominion Energy Gas Gas sales: Regulated $ 87 $ 119 $ 122 Nonregulated 20 13 10 Gas transportation and storage 1,435 1,307 1,366 NGL revenue 91 62 93 Other 181 137 125 Total operating revenue $ 1,814 $ 1,638 $ 1,716

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	N OTE NCOME AXES Judgment and the use of estimates are required in developing the provision for income taxes and reporting of tax-related tax-related The 2017 Tax Reform Act includes a broad range of tax reform provisions affecting the Companies as discussed in Note 2. The 2017 Tax Reform Act reduces the corporate income tax rate from 35% to 21% for tax years beginning after December 31, 2017. At the date of enactment, deferred tax assets and liabilities were remeasured based upon the new 21% enacted tax rate expected to apply when temporary differences are realized or settled. The specific provisions related to regulated public utilities in the 2017 Tax Reform Act generally allows for the continued deductibility of interest expense, changes the tax depreciation of certain property acquired after September 27, 2017, and continues certain rate normalization requirements for accelerated depreciation benefits. In December 2015, U.S. federal legislation was enacted, providing an extension of the 50% bonus depreciation allowance for qualifying expenditures incurred in 2015, 2016 and 2017. In addition, the legislation extended the 30% investment tax credit for qualifying expenditures incurred through 2019 and provides a phase down of the credit to 26% in 2020, 22% in 2021 and 10% in 2022 and thereafter. As indicated in Note 2, certain of the Companies’ operations, including accounting for income taxes, is subject to regulatory accounting treatment. For regulated operations, many of the changes in deferred taxes represent amounts probable of collection from or refund to customers, and are recorded as either an increase to a regulatory asset or liability. The 2017 Tax Reform Act includes provisions that stipulate how these excess deferred taxes may be passed back to customers for certain accelerated tax depreciation benefits. Potential refunds of other deferred taxes may be determined by state and federal regulators. See Note 13 for more information. The Companies have completed or have made a reasonable estimate for the measurement and accounting of certain effects of the 2017 Tax Reform Act which have been reflected in the Consolidated Financial Statements. The changes in deferred taxes were recorded as either an increase to a regulatory liability or as an adjustment to the deferred tax provision. The items reflected as provisional amounts are related to accelerated depreciation for tax purposes of certain property acquired and placed into service after September 27, 2017 and the impact of accelerated depreciation on state income taxes to the extent there is uncertainty on conformity to the new federal tax system. The determination of the income tax effects of the items reflected as provisional amounts represents a reasonable estimate, but will require additional analysis of historical records and further interpretation of the 2017 Tax Reform Act from yet to be issued U.S. Department of Treasury regulations, which will require more time, information and resources than currently available to the Companies. Continuing Operations Details of income tax expense for continuing operations including noncontrolling interests were as follows: Dominion Energy Virginia Power Dominion Energy Gas Year Ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 (millions) Current: Federal $ (1 ) $ (155 ) $ (24 ) $ 432 $ 168 $ 316 $ 16 $ (27 ) $ 90 State (26 ) 85 75 73 90 92 8 4 30 Total current expense (benefit) (27 ) (70 ) 51 505 258 408 24 (23 ) 120 Deferred: Federal 2017 Tax Reform Act impact (851 ) — — (93 ) — — (197 ) — — Taxes before operating loss carryforwards and investment tax credits 739 1,050 384 319 435 154 199 239 156 Tax utilization expense (benefit) of operating loss carryforwards 174 (161 ) 539 4 (2 ) 96 5 (2 ) 6 Investment tax credits (200 ) (248 ) (134 ) (23 ) (25 ) (11 ) — — — State 132 50 66 59 27 13 20 1 1 Total deferred expense (benefit) (6 ) 691 855 266 435 252 27 238 163 Investment tax credit-gross deferral 5 35 — 5 35 — — — — Investment tax credit-amortization (2 ) (1 ) (1 ) (2 ) (1 ) (1 ) — — — Total income tax expense (benefit) $ (30 ) $ 655 $ 905 $ 774 $ 727 $ 659 $ 51 $ 215 $ 283 The accounting for the reduction in the corporate income tax rate decreased deferred income tax expense by $851 million at Dominion Energy, $93 million at Virginia Power, and $197 million for Dominion Energy Gas for the year ending December 31, 2017. The decrease in deferred income taxes at Dominion Energy primarily relates to the remeasurement of deferred taxes on merchant operations and includes the effects at Virginia Power and Dominion Energy Gas. Virginia Power and Dominion Energy Gas have certain regulatory assets and liabilities that have not yet been charged or returned to customers through rates, or on which they do not earn a return, including unrecognized pension and other postretirement benefits. The remeasurement of the deferred taxes on these regulatory balances was charged to continuing operations in 2017. For ratemaking purposes, Dominion Energy Gas’ subsidiary DETI follows the cash method on pension contributions. Deferred taxes recorded on pension balances as required by GAAP are not included as a component of rates and therefore the remeasurement of these deferred taxes were charged to continuing operations in 2017. In 2016, Dominion Energy realized a taxable gain resulting from the contribution of Dominion Energy Questar Pipeline to Dominion Energy Midstream. The contribution and related transactions resulted in increases in the tax basis of Dominion Energy Questar Pipeline’s assets and the number of Dominion Energy Midstream’s common and convertible preferred units held by noncontrolling interests. The direct tax effects of the transactions included a provision for current income taxes ($212 million) and an offsetting benefit for deferred income taxes ($96 million) and were charged to common shareholders’ equity. The federal tax liability was reduced by $129 million of tax credits generated in 2016 that otherwise would have resulted in additional credit carryforwards and a $17 million benefit provided by the domestic production activities deduction. These benefits, as indirect effects of the contribution transaction, were reflected in Dominion Energy’s 2016 current federal income tax expense. In 2015, Dominion Energy’s current federal income tax benefit includes the recognition of a $20 million benefit related to a carryback to be filed for nuclear decommissioning expenditures included in its 2014 net operating loss. For continuing operations including noncontrolling interests, the statutory U.S. federal income tax rate reconciles to the Companies’ effective income tax rate as follows: Dominion Energy Virginia Power Dominion Energy Gas Year Ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 U.S. statutory rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Increases (reductions) resulting from: State taxes, net of federal benefit 2.0 2.4 3.7 3.7 3.8 3.9 2.4 0.5 2.7 Investment tax credits (6.3 ) (11.7 ) (4.7 ) (0.8 ) — (0.6 ) — — — Production tax credits (0.7 ) (0.8 ) (0.8 ) (0.4 ) (0.5 ) (0.6 ) — — — Valuation allowances 0.2 1.2 (0.3 ) — 0.1 — 0.3 — — Federal legislative change (27.5 ) — — (4.0 ) — — (29.5 ) — — State legislative change — (0.6 ) (0.1 ) — — — — — — AFUDC—equity (1.4 ) (0.6 ) (0.3 ) (0.6 ) (0.6 ) (0.6 ) (0.9 ) (0.2 ) 0.2 Employee stock ownership plan deduction (0.6 ) (0.6 ) (0.6 ) — — — — — — Other, net (1.7 ) (1.4 ) 0.1 0.6 (0.4 ) 0.6 0.4 0.1 0.3 Effective tax rate (1.0 )% 22.9 % 32.0 % 33.5 % 37.4 % 37.7 % 7.7 % 35.4 % 38.2 % In 2017, the Companies’ effective tax rates reflect the net benefit of remeasurement of deferred taxes resulting from the lower corporate income tax rate promulgated by the 2017 Tax Reform Act, and the completion of audits by state tax authorities that resulted in the recognition of previously unrecognized tax benefits. At December 31, 2016, Virginia Power’s unrecognized tax benefits included state refund claims for open tax years through 2011. Management believed settlement of the claims, including interest thereon, within the next twelve months was remote. In June 2017, Virginia Power received and accepted a cash offer to settle the refund claims. As a result of the settlement, Virginia Power decreased its unrecognized tax benefits by $8 million, and recognized a $2 million tax benefit, which impacted its effective tax rate. Also in connection with this settlement, Virginia Power realized interest income of $11 million, which is reflected in other income in the Consolidated Statements of Income. In 2016, Dominion Energy’s effective tax rate reflects a valuation allowance on a state credit not expected to be utilized by a Dominion Energy subsidiary which files a separate state return. The Companies’ deferred income taxes consist of the following: Dominion Energy Virginia Power Dominion Energy At December 31, 2017 2016 2017 2016 2017 2016 (millions) Deferred income taxes: Total deferred income tax assets $ 2,686 $ 1,827 $ 923 $ 268 $ 320 $ 126 Total deferred income tax liabilities 7,158 10,381 3,600 5,323 1,774 2,564 Total net deferred income tax liabilities $ 4,472 $ 8,554 $ 2,677 $5,055 $1,454 $ 2,438 Total deferred income taxes: Plant and equipment, primarily depreciation method and basis differences $ 5,056 $ 7,782 $ 2,969 $4,604 $1,132 $ 1,726 Excess deferred income taxes (1,050 ) — (687 ) — (244 ) — Nuclear decommissioning 829 1,240 260 406 — — Deferred state income taxes 834 747 378 321 227 204 Federal benefit of deferred state income taxes (175 ) (261 ) (79 ) (112 ) (48 ) (71 ) Deferred fuel, purchased energy and gas costs 1 (25 ) (3 ) (29 ) 2 4 Pension benefits 141 155 (104 ) (138 ) 419 646 Other postretirement benefits (51 ) (68 ) 44 49 (2 ) (6 ) Loss and credit carryforwards (1,536 ) (1,547 ) (111 ) (88 ) (4 ) (5 ) Valuation allowances 146 135 5 3 3 — Partnership basis differences 473 688 — — 26 43 Other (196 ) (292 ) 5 39 (57 ) (103 ) Total net deferred income tax liabilities $ 4,472 $ 8,554 $ 2,677 $5,055 $1,454 $ 2,438 Deferred Investment Tax Credits – Regulated Operations 51 48 51 48 — — Total Deferred Taxes and Deferred Investment Tax Credits $ 4,523 $ 8,602 $ 2,728 $5,103 $1,454 $ 2,438 The most significant impact reflected for the 2017 Tax Reform Act is the adjustment of the net accumulated deferred income tax liability for the reduction in the corporate income tax rate to 21%. In addition to amounts recognized in deferred income tax expense, the impacts of the 2017 Tax Reform Act decreased the accumulated deferred income tax liability by $3.1 billion at Dominion Energy, $1.9 billion at Virginia Power and $0.8 billion at Dominion Energy Gas at December 31, 2017. At Dominion Energy, the December 31, 2017 balance sheet reflects the impact of the 2017 Tax Reform Act on our regulatory liabilities which increased our regulatory liabilities by $4.2 billion, and created a corresponding deferred tax asset of $1.1 billion. At Virginia Power, our regulatory liabilities increased $2.6 billion, and created a deferred tax asset of $0.7 billion. At Dominion Energy Gas, our regulatory liabilities increased $1.0 billion, and created a deferred tax asset of $0.2 billion. These adjustments had no impact on 2017 cash flows. At December 31, 2017, Dominion Energy had the following deductible loss and credit carryforwards: Deductible Amount Deferred Tax Asset Valuation Expiration Period (millions) Federal losses $ 560 $ 118 $ — 2034 Federal investment credits — 938 — 2033-2037 Federal production credits — 129 — 2031-2037 Other federal credits — 58 — 2031-2037 State losses 1,366 103 (63 ) 2018-2037 State minimum tax credits — 90 — No expiration State investment and other credits — 100 (83 ) 2018-2027 Total $1,926 $1,536 $(146 ) At December 31, 2017, Virginia Power had the following deductible loss and credit carryforwards: Deductible Amount Deferred Tax Asset Valuation Allowance Expiration (millions) Federal losses $ 1 $ — $— 2034 Federal investment credits — 51 — 2034-2037 Federal production and other credits — 51 — 2031-2037 State investment credits — 9 (5 ) 2024 Total $ 1 $111 $(5 ) At December 31, 2017, Dominion Energy Gas had the following deductible loss and credit carryforwards: Deductible Amount Deferred Tax Asset Valuation Allowance Expiration Period (millions) Other federal credits $ — $1 $ 2032-2036 State losses 33 3 (3 ) 2036-2037 Total $33 $4 $ ) A reconciliation of changes in the Companies’ unrecognized tax benefits follows: Dominion Energy Virginia Power Dominion Energy Gas 2017 2016 2015 2017 2016 2015 2017 2016 2015 (millions) Balance at January 1 $ 64 $ 103 $ 145 $ 13 $ 12 $ 36 $ 7 $ 29 $29 Increases-prior period positions 1 9 2 — 4 — — 1 — Decreases-prior period positions (9 ) (44 ) (40 ) (1 ) (3 ) (25 ) — (19 ) — Increases-current period positions 5 6 8 — — 1 — — — Settlements with tax authorities (23 ) (8 ) (5 ) (8 ) — — (7 ) (4 ) — Expiration of statutes of limitations — (2 ) (7 ) — — — — — — Balance at December 31 $ 38 $ 64 $ 103 $ 4 $ 13 $ 12 $— $ 7 $29 Certain unrecognized tax benefits, or portions thereof, if recognized, would affect the effective tax rate. Changes in these unrecognized tax benefits may result from remeasurement of amounts expected to be realized, settlements with tax authorities and expiration of statutes of limitations. For Dominion Energy and its subsidiaries, these unrecognized tax benefits were $31 million, $45 million and $69 million at December 31, 2017, 2016 and 2015, respectively. For Dominion Energy, the change in these unrecognized tax benefits decreased income tax expense by $9 million, $18 million and $6 million in 2017, 2016 and 2015, respectively. For Virginia Power, these unrecognized tax benefits were $3 million, $9 million, and $8 million at December 31, 2017, 2016 and 2015, respectively. For Virginia Power, the change in these unrecognized tax benefits decreased income tax expense by $6 million in 2017 and increased income tax expense by $1 million and less than $1 million in 2016 and 2015, respectively. For Dominion Energy Gas, these unrecognized tax benefits were less than $1 million, $5 million and $19 million at December 31, 2017, 2016 and 2015, respectively. For Dominion Energy Gas, the change in these unrecognized tax benefits decreased income tax expense by $5 million, $11 million and less than $1 million in 2017, 2016 and 2015, respectively. Dominion Energy participates in the IRS Compliance Assurance Process which provides the opportunity to resolve complex tax matters with the IRS before filing its federal income tax returns, thus achieving certainty for such tax return filing positions agreed to by the IRS. In 2016 and 2017, the Companies submitted research credit claims for tax years 2012-2016. These claims are currently under IRS examination. With the exception of these research credit claims, the IRS has completed its audit of tax years through 2015. The statute of limitations has not yet expired for tax years after 2012. Although Dominion Energy has not received a final letter indicating no changes to its taxable income for tax year 2016, no material adjustments are expected. The IRS examination of tax year 2017 is ongoing. It is reasonably possible that settlement negotiations and expiration of statutes of limitations could result in a decrease in unrecognized tax benefits in 2018 by up to $13 million for Dominion Energy, $2 million for Virginia Power and less than $1 million for Dominion Energy Gas. If such changes were to occur, other than revisions of the accrual for interest on tax underpayments and overpayments, earnings could increase by up to $12 million for Dominion Energy, $2 million for Virginia Power and less than $1 million for Dominion Energy Gas. Otherwise, with regard to 2017 and prior years, Dominion Energy, Virginia Power and Dominion Energy Gas cannot estimate the range of reasonably possible changes to unrecognized tax benefits that may occur in 2018. For each of the major states in which Dominion Energy operates, the earliest tax year remaining open for examination is as follows: State Earliest Open Tax Year Pennsylvania (1) 2012 Connecticut 2014 Virginia (2) 2014 West Virginia (1) 2014 New York (1) 2011 Utah 2014 (1) Considered a major state for Dominion Energy Gas’ operations. (2) Considered a major state for Virginia Power’s operations. The Companies are also obligated to report adjustments resulting from IRS settlements to state tax authorities. In addition, if Dominion Energy utilizes operating losses or tax credits generated in years for which the statute of limitations has expired, such amounts are generally subject to examination.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Dominion Energy Gas Holdings, LLC
Fair Value Measurements	N OTE AIR ALUE EASUREMENTS Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (exit price) in an orderly transaction between market participants at the measurement date. However, the use of a mid-market mid-point Inputs and Assumptions The Companies maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Fair value is based on actively-quoted market prices, if available. In the absence of actively-quoted market prices, price information is sought from external sources, including broker quotes and industry publications. When evaluating pricing information provided by brokers and other pricing services, the Companies consider whether the broker is willing and able to trade at the quoted price, if the broker quotes are based on an active market or an inactive market and the extent to which brokers are utilizing a particular model if pricing is not readily available. If pricing information from external sources is not available, or if the Companies believe that observable pricing is not indicative of fair value, judgment is required to develop the estimates of fair value. In those cases the Companies must estimate prices based on available historical and near-term future price information and certain statistical methods, including regression analysis, that reflect their market assumptions. The Companies’ commodity derivative valuations are prepared by Dominion Energy’s ERM department. The ERM department creates daily mark-to-market mark-to-market mark-to-market mark-to-market For options and contracts with option-like characteristics where observable pricing information is not available from external sources, Dominion Energy and Virginia Power generally use a modified Black-Scholes Model that considers time value, the volatility of the underlying commodities and other relevant assumptions when estimating fair value. Dominion Energy and Virginia Power use other option models under special circumstances, including a Spread Approximation Model when contracts include different commodities or commodity locations and a Swing Option Model when contracts allow either the buyer or seller the ability to exercise within a range of quantities. For contracts with unique characteristics, the Companies may estimate fair value using a discounted cash flow approach deemed appropriate in the circumstances and applied consistently from period to period. For individual contracts, the use of different valuation models or assumptions could have a significant effect on the contract’s estimated fair value. The inputs and assumptions used in measuring fair value include the following: For commodity derivative contracts: • Forward commodity prices • Transaction prices • Price volatility • Price correlation • Volumes • Commodity location • Interest rates • Credit quality of counterparties and the Companies • Credit enhancements • Time value For interest rate derivative contracts: • Interest rate curves • Credit quality of counterparties and the Companies • Notional value • Credit enhancements • Time value For foreign currency derivative contracts: • Foreign currency forward exchange rates • Interest rates • Credit quality of counterparties and the Companies • Notional value • Credit enhancements • Time value For investments: • Quoted securities prices and indices • Securities trading information including volume and restrictions • Maturity • Interest rates • Credit quality The Companies regularly evaluate and validate the inputs used to estimate fair value by a number of methods, including review and verification of models, as well as various market price verification procedures such as the use of pricing services and multiple broker quotes to support the market price of the various commodities and investments in which the Companies transact. Levels The Companies also utilize the following fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: • Level 1—Quoted prices (unadjusted) in active markets for identical assets and liabilities that they have the ability to access at the measurement date. Instruments categorized in Level 1 primarily consist of financial instruments such as certain exchange-traded derivatives, and exchange-listed equities, U.S. and international equity securities, mutual funds and certain Treasury securities held in nuclear decommissioning trust funds for Dominion Energy and Virginia Power, benefit plan trust funds for Dominion Energy and Dominion Energy Gas, and rabbi trust funds for Dominion Energy. • Level 2—Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable for the asset or liability, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability, and inputs that are derived from observable market data by correlation or other means. Instruments categorized in Level 2 primarily include commodity forwards and swaps, interest rate swaps, foreign currency swaps and cash and cash equivalents, corporate debt instruments, government securities and other fixed income investments held in nuclear decommissioning trust funds for Dominion Energy and Virginia Power, benefit plan trust funds for Dominion Energy and Dominion Energy Gas and rabbi trust funds for Dominion Energy. • Level 3—Unobservable inputs for the asset or liability, including situations where there is little, if any, market activity for the asset or liability. Instruments categorized in Level 3 for the Companies consist of long-dated commodity derivatives, FTRs, certain natural gas and power options and other modeled commodity derivatives. The fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1) and the lowest priority to unobservable data (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. In these cases, the lowest level input that is significant to a fair value measurement in its entirety determines the applicable level in the fair value hierarchy. Assessing the significance of a particular input to the fair value measurement in its entirety requires judgment, considering factors specific to the asset or liability. Alternative investments, consisting of investments in partnerships, joint ventures and other alternative investments held in nuclear decommissioning and benefit plan trust funds, are generally valued using NAV based on the proportionate share of the fair value as determined by reference to the most recent audited fair value financial statements or fair value statements provided by the investment manager adjusted for any significant events occurring between the investment manager’s and the Companies’ measurement date. Alternative investments recorded at NAV are not classified in the fair value hierarchy. For derivative contracts, the Companies recognize transfers among Level 1, Level 2 and Level 3 based on fair values as of the first day of the month in which the transfer occurs. Transfers out of Level 3 represent assets and liabilities that were previously classified as Level 3 for which the inputs became observable for classification in either Level 1 or Level 2. Because the activity and liquidity of commodity markets vary substantially between regions and time periods, the availability of observable inputs for substantially the full term and value of the Companies’ over-the-counter Level 3 Valuations Fair value measurements are categorized as Level 3 when price or other inputs that are considered to be unobservable are significant to their valuations. Long-dated commodity derivatives are generally based on unobservable inputs due to the length of time to settlement and the absence of market activity and are therefore categorized as Level 3. FTRs are categorized as Level 3 fair value measurements because the only relevant pricing available comes from ISO auctions, which are generally not considered to be liquid markets. Other modeled commodity derivatives have unobservable inputs in their valuation, mostly due to non-transparent The Companies enter into certain physical and financial forwards, futures, options and swaps, which are considered Level 3 as they have one or more inputs that are not observable and are significant to the valuation. The discounted cash flow method is used to value Level 3 physical and financial forwards and futures contracts. An option model is used to value Level 3 physical and financial options. The discounted cash flow model for forwards and futures calculates mark-to-market mark-to-market The following table presents Dominion Energy’s quantitative information about Level 3 fair value measurements at December 31, 2017. The range and weighted average are presented in dollars for market price inputs and percentages for price volatility. Fair Value (millions) Valuation Techniques Unobservable Input Range Weighted Average (1) Assets Physical and financial forwards and futures: Natural gas (2) $ 84 Discounted cash flow Market price (per Dth) (4) (2) - 14 — FTRs 29 Discounted cash flow Market price (per MWh) (4) (1) - 7 2 Physical options: Natural gas 1 Option model Market price (per Dth) (4) 2 - 7 3 Price volatility (5) 26% - 54% 33 % Electricity 43 Option model Market price (per MWh) (4) 22 - 74 37 Price volatility (5) 13% - 63% 33 % Total assets $157 Liabilities Financial forwards: Liquids (3) $ 2 Discounted cash flow Market price (per Gal) (4) 0 - 2 1 FTRs $ 5 Discounted cash flow Market price (per MWh) (4) (4) - 6 — Total liabilities $ 7 (1) Averages weighted by volume. (2) Includes basis. (3) Includes NGLs and oil. (4) Represents market prices beyond defined terms for Levels 1 and 2. (5) Represents volatilities unrepresented in published markets. Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows: Significant Unobservable Inputs Position Change to Input Impact on Fair Value Measurement Market price Buy Increase (decrease) Gain (loss) Market price Sell Increase (decrease) Loss (gain) Price volatility Buy Increase (decrease) Gain (loss) Price volatility Sell Increase (decrease) Loss (gain) Nonrecurring Fair Value Measurements D OMINION NERGY See Note 9 for information regarding an impairment charge recognized associated with Dominion Energy’s equity method investment in Fowler Ridge. A TLANTIC OAST IPELINE UARANTEE GREEMENT In October 2017, Dominion Energy entered into a guarantee agreement in connection with Atlantic Coast Pipeline’s obligation under a $3.4 billion revolving credit facility. See Note 22 for more information about the guarantee agreement associated with Atlantic Coast Pipeline’s revolving credit facility. Dominion Energy recorded a liability of $30 million, the fair value of the guarantee at inception, associated with the guarantee agreement. The fair value was estimated using a discounted cash flow method and is considered a Level 3 fair value measurement due to the use of a significant unobservable input related to the interest rate differential between the interest rate charged on the guaranteed revolving credit facility and the estimated interest rate that would have been charged had the loan not been guaranteed. Recurring Fair Value Measurements Fair value measurements are separately disclosed by level within the fair value hierarchy with a separate reconciliation of fair value measurements categorized as Level 3. Fair value disclosures for assets held in Dominion Energy’s and Dominion Energy Gas’ pension and other postretirement benefit plans are presented in Note 21. D OMINION NERGY The following table presents Dominion Energy’s assets and liabilities that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions: Level 1 Level 2 Level 3 Total (millions) December 31, 2017 Assets Derivatives: Commodity $ — $ 101 $157 $ 258 Interest rate — 17 — 17 Foreign currency — 32 — 32 Investments (1) Equity securities: U.S. 3,493 — — 3,493 Fixed income: Corporate debt instruments — 444 — 444 Government securities 307 794 — 1,101 Cash equivalents and other 34 — — 34 Total assets $ 3,834 $ 1,388 $157 $ 5,379 Liabilities Derivatives: Commodity $ — $ 190 $ 7 $ 197 Interest rate — 85 — 85 Foreign currency — 2 — 2 Total liabilities $ — $ 277 $ 7 $ 284 December 31, 2016 Assets Derivatives: Commodity $ — $ 115 $147 $ 262 Interest rate — 17 — 17 Investments (1) Equity securities: U.S. 2,913 — — 2,913 Fixed income: Corporate debt instruments — 487 — 487 Government securities 424 614 — 1,038 Cash equivalents and other 5 — — 5 Total assets $ 3,342 $ 1,233 $147 $ 4,722 Liabilities Derivatives: Commodity $ — $ 88 $ 8 $ 96 Interest rate — 53 — 53 Foreign currency — 6 — 6 Total liabilities $ — $ 147 $ 8 $ 155 (1) Includes investments held in the nuclear decommissioning and rabbi trusts. Excludes $88 million and $89 million of assets at December 31, 2017 and 2016, respectively, measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy. The following table presents the net change in Dominion Energy’s assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category: 2017 2016 2015 (millions) Balance at January 1, $ 139 $ 95 $ 107 Total realized and unrealized gains (losses): Included in earnings (38 ) (35 ) (5 ) Included in other comprehensive loss (2 ) — (9 ) Included in regulatory assets/liabilities 42 (39 ) (4 ) Settlements 6 38 9 Purchases — 87 — Transfers out of Level 3 3 (7 ) (3 ) Balance at December 31, $ 150 $ 139 $ 95 The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets still held at the reporting date $ 2 $ (1 ) $ 2 The following table presents Dominion Energy’s gains and losses included in earnings in the Level 3 fair value category: Operating Revenue Electric Fuel and Other Energy-Related Purchases Purchased Gas Total (millions) Year Ended December 31, 2017 Total gains (losses) included in earnings $ 3 $(42 ) $ 1 $ (38 ) The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date 2 — — 2 Year Ended December 31, 2016 Total gains (losses) included in earnings $— $(35 ) $— $ (35 ) The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date — (1 ) — (1 ) Year Ended December 31, 2015 Total gains (losses) included in earnings $ 6 $(11 ) $— $ (5 ) The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date 1 1 — 2 V IRGINIA OWER The following table presents Virginia Power’s quantitative information about Level 3 fair value measurements at December 31, 2017. The range and weighted average are presented in dollars for market price inputs and percentages for price volatility. Fair Value (millions) Valuation Techniques Unobservable Input Range Weighted Average (1) Assets Physical and financial forwards and futures: Natural gas (2) $ 81 Discounted cash flow Market price (per Dth) (3) (2)-7 (1 ) FTRs 27 Discounted cash flow Market price (per MWh) (3) (1)-7 2 Physical options: Natural gas 1 Option model Market price (per Dth) (3) 2-7 3 Price volatility (4) 26%-54% 33 % Electricity 43 Option model Market price (per MWh) (3) 22-74 37 Price volatility (4) 13%-63% 33 % Total assets $152 Liabilities: Financial forwards: FTRs $ 5 Discounted cash flow Market price (per MWh) (3) (4)-6 — Total liabilities $ 5 (1) Averages weighted by volume. (2) Includes basis. (3) Represents market prices beyond defined terms for Levels 1 and 2. (4) Represents volatilities unrepresented in published markets. Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows: Significant Unobservable Position Change to Input Impact on Fair Value Measurement Market price Buy Increase (decrease) Gain (loss) Market price Sell Increase (decrease) Loss (gain) Price volatility Buy Increase (decrease) Gain (loss) Price volatility Sell Increase (decrease) Loss (gain) The following table presents Virginia Power’s assets and liabilities that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions: Level 1 Level 2 Level 3 Total (millions) December 31, 2017 Assets Derivatives: Commodity $ — $ 14 $ 152 $ 166 Investments (1) Equity securities: U.S. 1,566 — — 1,566 Fixed income: Corporate debt instruments — 224 — 224 Government securities 168 326 — 494 Cash equivalents and other 16 — — 16 Total assets $ 1,750 $ 564 $ 152 $ 2,466 Liabilities Derivatives: Commodity $ — $ 4 $ 5 $ 9 Interest rate — 57 — 57 Total liabilities $ — $ 61 $ 5 $ 66 December 31, 2016 Assets Derivatives: Commodity $ — $ 43 $ 145 $ 188 Interest rate — 6 — 6 Investments (1) Equity securities: U.S. 1,302 — — 1,302 Fixed income: Corporate debt instruments — 277 — 277 Government securities 136 291 — 427 Total assets $ 1,438 $ 617 $ 145 $ 2,200 Liabilities Derivatives: Commodity $ — $ 8 $ 2 $ 10 Interest rate — 21 — 21 Total liabilities $ — $ 29 $ 2 $ 31 (1) Includes investments held in the nuclear decommissioning trusts. Excludes $27 million and $26 million of assets at December 31, 2017 and 2016, respectively, measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy. The following table presents the net change in Virginia Power’s assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category: 2017 2016 2015 (millions) Balance at January 1, $ 143 $ 93 $ 102 Total realized and unrealized gains (losses): Included in earnings (43 ) (35 ) (13 ) Included in regulatory assets/liabilities 40 (37 ) (5 ) Settlements 7 35 13 Purchases — 87 — Transfers out of Level 3 — — (4 ) Balance at December 31, $ 147 $ 143 $ 93 The gains and losses included in earnings in the Level 3 fair value category were classified in electric fuel and other energy-related purchases expense in Virginia Power’s Consolidated Statements of Income for the years ended December 31, 2017, 2016 and 2015. There were no unrealized gains and losses included in earnings in the Level 3 fair value category relating to assets/liabilities still held at the reporting date for the years ended December 31, 2017, 2016 and 2015. D OMINION NERGY AS The following table presents Dominion Energy Gas’ quantitative information about Level 3 fair value measurements at December 31, 2017. The range and weighted average are presented in dollars for market price inputs. Fair Value (millions) Valuation Unobservable Range Weighted Average (1) Liabilities: Financial forwards: NGLs $2 Discounted Market (2) 0 - 1 1 Total liabilities $2 (1) Averages weighted by volume. (2) Represents market prices beyond defined terms for Levels 1 and 2. Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows: Significant Unobservable Inputs Position Change to Input Impact on Measurement Market price Buy Increase (decrease) Gain (loss) Market price Sell Increase (decrease) Loss (gain) The following table presents Dominion Energy Gas’ assets and liabilities for commodity and foreign currency derivatives that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions: Level 1 Level 2 Level 3 Total (millions) December 31, 2017 Assets Foreign currency $ — $32 $ $ 32 Total assets $ — $32 $ $ 32 Liabilities Commodity $ — $ 4 $ 2 $ 6 Foreign currency — 2 — 2 Total liabilities $ — $ 6 $ 2 $ 8 December 31, 2016 Liabilities Commodity $ — $ 3 $ 2 $ 5 Foreign currency — 6 — 6 Total liabilities $ — $ 9 $ 2 $ 11 The following table presents the net change in Dominion Energy Gas’ derivative assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category: 2017 2016 2015 (millions) Balance at January 1, $ (2 ) $ 6 $ 2 Total realized and unrealized gains (losses): Included in earnings — — 1 Included in other comprehensive loss (3 ) — (5 ) Settlements — — (1 ) Transfers out of Level 3 3 (8 ) 9 Balance at December 31, $ (2 ) $ (2 ) $ 6 The gains and losses included in earnings in the Level 3 fair value category were classified in operating revenue in Dominion Energy Gas’ Consolidated Statements of Income for the years ended December 31, 2017, 2016 and 2015. There were no unrealized gains and losses included in earnings in the Level 3 fair value category relating to assets/liabilities still held at the reporting date for the years ended December 31, 2017, 2016 and 2015. Fair Value of Financial Instruments Substantially all of the Companies’ financial instruments are recorded at fair value, with the exception of the instruments described below, which are reported at historical cost. Estimated fair values have been determined using available market information and valuation methodologies considered appropriate by management. The carrying amount of cash and cash equivalents, restricted cash and equivalents, customer and other receivables, affiliated receivables, short-term debt, affiliated current borrowings, payables to affiliates and accounts payable are representative of fair value because of the short-term nature of these instruments. For the Companies’ financial instruments that are not recorded at fair value, the carrying amounts and estimated fair values are as follows: December 31, 2017 2016 Carrying Amount Estimated Fair Value (1) Carrying Amount Estimated Fair Value (1) (millions) Dominion Energy Long-term debt, including securities due within one year (2) $ 28,666 $31,233 $ 26,587 $28,273 Junior subordinated notes (3) 3,981 4,102 2,980 2,893 Remarketable subordinated notes (3) 1,379 1,446 2,373 2,418 Virginia Power Long-term debt, including securities due within one year (3) $ 11,346 $12,842 $ 10,530 $11,584 Dominion Energy Gas Long-term debt, including securities due within one year (4) $ 3,570 $ 3,719 $ 3,528 $ 3,603 (1) Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issues with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value. (2) Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium, and foreign currency remeasurement adjustments. At December 31, 2017, and 2016, includes the valuation of certain fair value hedges associated with Dominion Energy’s fixed rate debt of $(22) million and $(1) million, respectively. (3) Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium. (4) Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium, and foreign currency remeasurement adjustments.

Derivatives and Hedge Accountin

Derivatives and Hedge Accounting Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedge Accounting Activities	N OTE ERIVATIVES ND EDGE CCOUNTING CTIVITIES The Companies are exposed to the impact of market fluctuations in the price of electricity, natural gas and other energy-related products they market and purchase, as well as interest rate and foreign currency exchange rate risks of their business operations. The Companies use derivative instruments to manage exposure to these risks, and designate certain derivative instruments as fair value or cash flow hedges for accounting purposes. As discussed in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivatives are deferred as regulatory assets or regulatory liabilities until the related transactions impact earnings. See Note 6 for further information about fair value measurements and associated valuation methods for derivatives. Derivative assets and liabilities are presented gross on the Companies’ Consolidated Balance Sheets. Dominion Energy’s derivative contracts include both over-the-counter over-the-counter Over-the-counter over-the-counter In general, most over-the-counter over-the-counter D OMINION NERGY Balance Sheet Presentation The tables below present Dominion Energy’s derivative asset and liability balances by type of financial instrument, before and after the effects of offsetting: December 31, 2017 December 31, 2016 Gross Amounts of Assets Gross Amounts Offset in the Net Amounts of Presented in the Gross Amounts of Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet (millions) Commodity contracts: Over-the-counter $174 $— $174 $211 $— $211 Exchange 80 — 80 44 — 44 Interest rate contracts: Over-the-counter 17 — 17 17 — 17 Foreign currency contracts: Over-the-counter 32 — 32 — — — Total derivatives, subject to a master netting or similar arrangement 303 — 303 272 — 272 Total derivatives, not subject to a master netting or similar arrangement 4 — 4 7 — 7 Total $307 $— $307 $279 $— $279 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Net Amounts of Assets Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Received Net Amounts Net Amounts of Assets Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Received Net Amounts (millions) Commodity contracts: Over-the-counter $174 $ 9 $— $165 $211 $14 $— $197 Exchange 80 80 — — 44 44 — — Interest rate contracts: Over-the-counter 17 8 — 9 17 9 — 8 Foreign currency contracts: Over-the-counter 32 2 — 30 — — — — Total $303 $99 $— $204 $272 $67 $— $205 December 31, 2017 December 31, 2016 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $ 76 $— $ 76 $ 23 $— $ 23 Exchange 120 — 120 71 — 71 Interest rate contracts: Over-the-counter 85 — 85 53 — 53 Foreign currency contracts: Over-the-counter 2 — 2 6 — 6 Total derivatives, subject to a master netting or similar arrangement 283 — 283 153 — 153 Total derivatives, not subject to a master netting or similar arrangement 1 — 1 2 — 2 Total $284 $— $284 $155 $— $155 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Paid Net Amounts Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Paid Net Amounts (millions) Commodity contracts: Over-the-counter $ 76 $ 9 $ 6 $ 61 $ 23 $14 $— $ 9 Exchange 120 80 40 — 71 44 27 — Interest rate contracts: Over-the-counter 85 8 — 77 53 9 — 44 Foreign currency contracts: Over-the-counter 2 2 — — 6 — — 6 Total $283 $99 $46 $138 $153 $67 $27 $59 Volumes The following table presents the volume of Dominion Energy’s derivative activity as of December 31, 2017. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions, except in the case of offsetting transactions, for which they represent the absolute value of the net volume of their long and short positions. Current Noncurrent Natural Gas (bcf): Fixed price (1) 77 19 Basis 163 600 Electricity (MWh): Fixed price 10,552,363 364,990 FTRs 46,494,865 — Liquids (Gal) (2) 44,153,704 10,087,200 Interest rate (3) $ 1,950,000,000 $ 4,192,517,177 Foreign currency (3)(4) $ — $ 280,000,000 (1) Includes options. (2) Includes NGLs and oil. (3) Maturity is determined based on final settlement period. (4) Euro equivalent volumes are € 250,000,000. Ineffectiveness and AOCI For the years ended December 31, 2017, 2016 and 2015, gains or losses on hedging instruments determined to be ineffective and amounts excluded from the assessment of effectiveness were not material. Amounts excluded from the assessment of effectiveness include gains or losses attributable to changes in the time value of options and changes in the differences between spot prices and forward prices. The following table presents selected information related to gains (losses) on cash flow hedges included in AOCI in Dominion Energy’s Consolidated Balance Sheet at December 31, 2017: AOCI After-Tax Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax Maximum Term (millions) Commodities: Gas $ (2 ) $ (3 ) 34 months Electricity (55 ) (55 ) 12 months Other (4 ) (4 ) 15 months Interest rate (246 ) (10 ) 384 months Foreign currency 5 (1 ) 102 months Total $(302 ) $(73 ) The amounts that will be reclassified from AOCI to earnings will generally be offset by the recognition of the hedged transactions (e.g., anticipated sales) in earnings, thereby achieving the realization of prices contemplated by the underlying risk management strategies and will vary from the expected amounts presented above as a result of changes in market prices, interest rates and foreign currency exchange rates. Fair Value and Gains and Losses on Derivative Instruments The following tables present the fair values of Dominion Energy’s derivatives and where they are presented in its Consolidated Balance Sheets: Fair Value – Derivatives Hedge Accounting Fair Value – Derivatives Hedge Accounting Total (millions) At December 31, 2017 ASSETS Current Assets Commodity $ 5 $158 $ 163 Interest rate 6 — 6 Total current derivative assets (1) 11 158 169 Noncurrent Assets Commodity — 95 95 Interest rate 11 — 11 Foreign currency 32 — 32 Total noncurrent derivative assets (2) 43 95 138 Total derivative assets $ 54 $253 $ 307 LIABILITIES Current Liabilities Commodity $103 $ 92 $ 195 Interest rate 53 — 53 Foreign currency 2 — 2 Total current derivative liabilities (3) 158 92 250 Noncurrent Liabilities Commodity 1 1 2 Interest rate 32 — 32 Total noncurrent derivative liabilities (4) 33 1 34 Total derivative liabilities $191 $ 93 $ 284 At December 31, 2016 ASSETS Current Assets Commodity $ 29 $101 $ 130 Interest rate 10 — 10 Total current derivative assets (1) 39 101 140 Noncurrent Assets Commodity — 132 132 Interest rate 7 — 7 Total noncurrent derivative assets (2) 7 132 139 Total derivative assets $ 46 $233 $ 279 LIABILITIES Current Liabilities Commodity $ 51 $ 41 $ 92 Interest rate 33 — 33 Foreign currency 3 — 3 Total current derivative liabilities (3) 87 41 128 Noncurrent Liabilities Commodity 1 3 4 Interest rate 20 — 20 Foreign currency 3 — 3 Total noncurrent derivative liabilities (4) 24 3 27 Total derivative liabilities $111 $ 44 $ 155 (1) Current derivative assets are presented in other current assets in Dominion Energy’s Consolidated Balance Sheets. (2) Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy’s Consolidated Balance Sheets. (3) Current derivative liabilities are presented in other current liabilities in Dominion Energy’s Consolidated Balance Sheets. (4) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy’s Consolidated Balance Sheets. The following table presents the gains and losses on Dominion Energy’s derivatives, as well as where the associated activity is presented in its Consolidated Balance Sheets and Statements of Income: Derivatives in cash flow hedging relationships Amount of in AOCI on Derivatives Portion) (1) Amount of From AOCI Increase (Decrease) in Derivatives Subject to Regulatory (2) (millions) Year Ended December 31, 2017 Derivative type and location of gains (losses): Commodity: Operating revenue $ 81 Purchased gas (2 ) Total commodity $ 1 $ 79 $ — Interest rate (3) (8 ) (52 ) (58 ) Foreign currency (4) 18 20 — Total $ 11 $ 47 $(58 ) Year Ended December 31, 2016 Derivative type and location of gains (losses): Commodity: Operating revenue $330 Purchased gas (13 ) Electric fuel and other energy-related purchases (10 ) Total commodity $164 $307 $ — Interest rate (3) (66 ) (31 ) (26 ) Foreign currency (4) (6 ) (17 ) — Total $ 92 $259 $(26 ) Year Ended December 31, 2015 Derivative type and location of gains (losses): Commodity: Operating revenue $203 Purchased gas (15 ) Electric fuel and other energy-related purchases (1 ) Total commodity $230 $187 $ 4 Interest rate (3) (46 ) (11 ) (13 ) Total $184 $176 $ (9 ) (1) Amounts deferred into AOCI have no associated effect in Dominion Energy’s Consolidated Statements of Income. (2) Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion Energy’s Consolidated Statements of Income. (3) Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in interest and related charges. (4) Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in other income. Derivatives not designated as hedging instruments Amount of Gain (Loss) Recognized in Income on Derivatives (1) Year Ended December 31, 2017 2016 2015 (millions) Derivative type and location of gains (losses): Commodity: Operating revenue $ 18 $ 2 $ 24 Purchased gas (3 ) 4 (14 ) Electric fuel and other energy-related purchases (59 ) (70 ) (14 ) Other operations & maintenance (1 ) 1 — Interest rate (2) — — (1 ) Total $(45 ) $(63 ) $ (5 ) (1) Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion Energy’s Consolidated Statements of Income. (2) Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in interest and related charges. V IRGINIA OWER Balance Sheet Presentation The tables below present Virginia Power’s derivative asset and liability balances by type of financial instrument, before and after the effects of offsetting: December 31, 2017 December 31, 2016 Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets Presented Consolidated Balance Sheet Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $155 $— $155 $147 $— $147 Interest rate contracts: Over-the-counter — — — 6 — 6 Total derivatives, subject to a master netting or similar arrangement 155 — 155 153 — 153 Total derivatives, not subject to a master netting or similar arrangement 11 — 11 41 — 41 Total $166 $— $166 $194 $— $194 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Net Amounts of in the Consolidated Balance Sheet Financial Cash Collateral Received Net Amounts Net Amounts of Assets Presented in Balance Sheet Financial Instruments Cash Collateral Received Net Amounts (millions) Commodity contracts: Over-the-counter $155 $ 4 $— $151 $147 $ 2 $— $145 Interest rate contracts: Over-the-counter — — — — 6 — — 6 Total $155 $ 4 $— $151 $153 $ 2 $— $151 December 31, 2017 December 31, 2016 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $ 4 $— $ 4 $ 2 $— $ 2 Interest rate contracts: Over-the-counter 57 — 57 21 — 21 Total derivatives, subject to a master netting or similar arrangement 61 — 61 23 — 23 Total derivatives, not subject to a master netting or similar arrangement 5 — 5 8 — 8 Total $66 $— $66 $31 $— $31 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Gross Amounts Not Offset in the Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Paid Net Amounts Net Amounts of Liabilities Presented Financial Instruments Cash Collateral Paid Net Amounts (millions) Commodity contracts: Over-the-counter $ 4 $ 4 $— $— $ 2 $ 2 $— $— Interest rate contracts: Over-the-counter 57 — — 57 21 — — 21 Total $61 $ 4 $— $57 $23 $ 2 $— $21 Volumes The following table presents the volume of Virginia Power’s derivative activity at December 31, 2017. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions, except in the case of offsetting transactions, for which they represent the absolute value of the net volume of their long and short positions. Current Noncurrent Natural Gas (bcf): Fixed price (1) 33 5 Basis 79 540 Electricity (MWh): Fixed price (1) 1,453,910 364,990 FTRs 42,582,981 — Interest rate (2) $ 1,150,000,000 $ 300,000,000 (1) Includes options. (2) Maturity is determined based on final settlement period. Ineffectiveness and AOCI For the years ended December 31, 2017, 2016 and 2015, gains or losses on hedging instruments determined to be ineffective were not material. The following table presents selected information related to losses on cash flow hedges included in AOCI in Virginia Power’s Consolidated Balance Sheet at December 31, 2017: AOCI After-Tax Amounts Expected After-Tax Maximum (millions) Interest rate $(12 ) $(1 ) 384 months Total $(12 ) $(1 ) The amounts that will be reclassified from AOCI to earnings will generally be offset by the recognition of the hedged transactions (e.g., interest payments) in earnings, thereby achieving the realization of interest rates contemplated by the underlying risk management strategies and will vary from the expected amounts presented above as a result of changes in interest rates. Fair Value and Gains and Losses on Derivative Instruments The following tables present the fair values of Virginia Power’s derivatives and where they are presented in its Consolidated Balance Sheets: Fair Value - Derivatives under Hedge Accounting Fair Value - Derivatives not under Hedge Accounting Total Fair Value (millions) At December 31, 2017 ASSETS Current Assets Commodity $— $ 75 $ 75 Total current derivative assets (1) — 75 75 Noncurrent Assets Commodity — 91 91 Total noncurrent derivative assets — 91 91 Total derivative assets $— $166 $166 LIABILITIES Current Liabilities Commodity $— $ 9 $ 9 Interest rate 44 — 44 Total current derivative liabilities (2) 44 9 53 Noncurrent Liabilities Interest rate 13 — 13 Total noncurrent derivatives liabilities (3) 13 — 13 Total derivative liabilities $57 $ 9 $ 66 At December 31, 2016 ASSETS Current Assets Commodity $— $ 60 $ 60 Interest rate 6 — 6 Total current derivative assets (1) 6 60 66 Noncurrent Assets Commodity — 128 128 Total noncurrent derivative assets — 128 128 Total derivative assets $6 $188 $194 LIABILITIES Current Liabilities Commodity $— $ 10 $ 10 Interest rate 8 — 8 Total current derivative liabilities (2) 8 10 18 Noncurrent Liabilities Interest rate 13 — 13 Total noncurrent derivative liabilities (3) 13 — 13 Total derivative liabilities $21 $ 10 $ 31 (1) Current derivative assets are presented in other current assets in Virginia Power’s Consolidated Balance Sheets. (2) Current derivative liabilities are presented in other current liabilities in Virginia Power’s Consolidated Balance Sheets. (3) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Virginia Power’s Consolidated Balance Sheets. The following tables present the gains and losses on Virginia Power’s derivatives, as well as where the associated activity is presented in its Consolidated Balance Sheets and Statements of Income: Derivatives in cash flow hedging Amount of Gain (Loss) Recognized in AOCI on (Effective Portion) (1) Amount of Gain (Loss) Reclassified From AOCI to Income Increase (2) (millions) Year Ended December 31, 2017 Derivative type and location of gains (losses): Interest rate (3) $(8 ) $(1 ) $(58 ) Total $(8 ) $(1 ) $(58 ) Year Ended December 31, 2016 Derivative type and location of gains (losses): Interest rate (3) $(3 ) $(1 ) $(26 ) Total $(3 ) $(1 ) $(26 ) Year Ended December 31, 2015 Derivative type and location of gains (losses): Commodity: Electric fuel and other energy-related purchases $(1 ) Total commodity $— $(1 ) $ 4 Interest rate (3) (3 ) — (13 ) Total $(3 ) $(1 ) $ (9 ) (1) Amounts deferred into AOCI have no associated effect in Virginia Power’s Consolidated Statements of Income. (2) Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power’s Consolidated Statements of Income. (3) Amounts recorded in Virginia Power’s Consolidated Statements of Income are classified in interest and related charges. Derivatives not designated as hedging instruments Amount of Gain (Loss) Recognized in Income on Derivatives (1) Year Ended December 31, 2017 2016 2015 (millions) Derivative type and location of gains (losses): Commodity (2) $(57 ) $(70 ) $(13 ) Total $(57 ) $(70 ) $(13 ) (1) Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power’s Consolidated Statements of Income. (2) Amounts recorded in Virginia Power’s Consolidated Statements of Income are classified in electric fuel and other energy-related purchases. D OMINION NERGY AS Balance Sheet Presentation The tables below present Dominion Energy Gas’ derivative asset and liability balances by type of financial instrument, before and after the effects of offsetting: December 31, 2017 December 31, 2016 Gross Amounts of Assets Gross Amounts Offset in the Net Amounts of Gross Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Presented in the Balance Sheet (millions) Foreign currency contracts: Over-the-counter $32 $— $32 $— $— $— Total derivatives, subject to a master netting or similar arrangement $32 $— $32 $— $— $— December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Balance Sheet Net Amounts of Balance Sheet Financial Instruments Cash Collateral Received Net Amounts Net Amounts of Balance Sheet Financial Instruments Cash Collateral Received Net Amounts (millions) Foreign currency contracts: Over-the-counter $32 $2 $— $30 $— $— $— $— Total $32 $2 $— $30 $— $— $— $— December 31, 2017 December 31, 2016 Gross Amounts of Gross Amounts Offset in the Net Amounts of Liabilities Presented in the Consolidated Gross Amounts of Gross Amounts Offset in the Net Amounts of Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $6 $— $6 $ 5 $— $ 5 Foreign currency contracts: Over-the-counter 2 — 2 6 — 6 Total derivatives, subject to a master netting or similar arrangement $8 $— $8 $11 $— $11 December 31, 2017 December 31, 2016 Gross Amounts Not Offset Gross Amounts Not Offset in the Consolidated Net Amounts of Financial Cash Collateral Paid Net Amounts Net Amounts of Financial Cash Collateral Paid Net Amounts (millions) Commodity contracts Over-the-counter $6 $— $— $ 6 $ 5 $— $— $ 5 Foreign currency contracts: Over-the-counter 2 2 — — 6 — — 6 Total $8 $ 2 $— $ 6 $11 $— $— $11 Volumes The following table presents the volume of Dominion Energy Gas’ derivative activity at December 31, 2017. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions, except in the case of offsetting transactions, for which they represent the absolute value of the net volume of their long and short positions. Current Noncurrent Natural Gas (bcf): Basis 1 — NGLs (Gal) 40,961,704 8,491,200 Foreign currency (1) $ — $ 280,000,000 (1) Maturity is determined based on final settlement period. Euro equivalent volumes are €250,000,000. Ineffectiveness and AOCI For the years ended December 31, 2017, 2016 and 2015, gains or losses on hedging instruments determined to be ineffective were not material. The following table presents selected information related to gains (losses) on cash flow hedges included in AOCI in Dominion Energy Gas’ Consolidated Balance Sheet at December 31, 2017: AOCI After-Tax Amounts Expected After-Tax Maximum (millions) Commodities: NGLs $ (4 ) $(4 ) 15 months Interest rate (25 ) (3 ) 324 months Foreign currency 6 (1 ) 102 months Total $(23 ) $(8 ) The amounts that will be reclassified from AOCI to earnings will generally be offset by the recognition of the hedged transactions (e.g., anticipated sales) in earnings, thereby achieving the realization of prices contemplated by the underlying risk management strategies and will vary from the expected amounts presented above as a result of changes in market prices, interest rates, and foreign currency exchange rates. Fair Value and Gains and Losses on Derivative Instruments The following tables present the fair values of Dominion Energy Gas’ derivatives and where they are presented in its Consolidated Balance Sheets: Fair Value- Under Accounting Fair Value- Not Under Accounting Total Fair Value (millions) At December 31, 2017 ASSETS Noncurrent Assets Foreign currency $32 $— $32 Total noncurrent derivative assets (1) 32 — 32 Total derivative assets $32 $— $32 LIABILITIES Current Liabilities Commodity $ 6 $— $ 6 Foreign currency 2 — 2 Total current derivative liabilities (2) 8 — 8 Total derivative liabilities $ 8 $— $ 8 At December 31, 2016 LIABILITIES Current Liabilities Commodity $ 4 $— $ 4 Foreign currency 3 — 3 Total current derivative liabilities (2) 7 — 7 Noncurrent Liabilities Commodity 1 — 1 Foreign currency 3 — 3 Total noncurrent derivative liabilities (3) 4 — 4 Total derivative liabilities $11 $— $11 (1) Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy Gas’ Consolidated Balance Sheets. (2) Current derivative liabilities are presented in other current liabilities in Dominion Energy Gas’ Consolidated Balance Sheets. (3) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy Gas’ Consolidated Balance Sheets. Combined Notes to Consolidated Financial Statements, Continued The following tables present the gains and losses on Dominion Energy Gas’ derivatives, as well as where the associated activity is presented in its Consolidated Balance Sheets and Statements of Income: Derivatives in cash flow hedging relationships Amount of Gain Derivatives (1) Amount of (millions) Year Ended December 31, 2017 Derivative Type and Location of Gains (Losses): Commodity: Operating revenue $ (8 ) Total commodity $(10 ) $ (8 ) Interest rate (2) — (5 ) Foreign currency (3) 18 20 Total $ 8 $ 7 Year Ended December 31, 2016 Derivative Type and Location of Gains (Losses): Commodity: Operating revenue $ 4 Total commodity $(12 ) $ 4 Interest rate (2) (8 ) (2 ) Foreign currency (3) (6 ) (17 ) Total $(26 ) $(15 ) Year Ended December 31, 2015 Derivative Type and Location of Gains (Losses): Commodity: Operating revenue $ 6 Total commodity $ 16 $ 6 Interest rate (2) (6) — Total $ 10 $ 6 (1) Amounts deferred into AOCI have no associated effect in Dominion Energy Gas’ Consolidated Statements of Income. (2) Amounts recorded in Dominion Energy Gas’ Consolidated Statements of Income are classified in interest and related charges. (3) Amounts recorded in Dominion Energy Gas’ Consolidated Statements of Income are classified in other income. Derivatives not designated as hedging instruments Amount of Gain (Loss) Recognized in Income on Derivatives Year Ended December 31, 2017 2016 2015 (millions) Derivative type and location of gains (losses): Commodity Operating revenue $— $1 $6 Total $— $1 $6

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	N OTE ARNINGS ER HARE The following table presents the calculation of Dominion Energy’s basic and diluted EPS: 2017 2016 2015 (millions, except EPS) Net income attributable to Dominion Energy $ 2,999 $ 2,123 $ 1,899 Average shares of common stock outstanding – Basic 636.0 616.4 592.4 Net effect of dilutive securities (1) — 0.7 1.3 Average shares of common stock outstanding – Diluted 636.0 617.1 593.7 Earnings Per Common Share – Basic $ 4.72 $ 3.44 $ 3.21 Earnings Per Common Share – Diluted $ 4.72 $ 3.44 $ 3.20 (1) Dilutive securities consist primarily of the 2013 Equity Units for 2016 and 2015. See Note 17 for more information. The 2014 Equity Units were excluded from the calculation of diluted EPS for the years ended December 31, 2016 and 2015, as the dilutive stock price threshold was not met. The 2016 Equity Units were excluded from the calculation of diluted EPS for the year ended December 31, 2017 and 2016, as the dilutive stock price threshold was not met. See Note 17 for more information. The Dominion Energy Midstream convertible preferred units are potentially dilutive securities but had no effect on the calculation of diluted EPS for the years ended December 31, 2017 and 2016. See Note 19 for more information.

Investments

Investments	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Investments	N OTE NVESTMENTS D OMINION NERGY Equity and Debt Securities R ABBI RUST ECURITIES Marketable equity and debt securities and cash equivalents held in Dominion Energy’s rabbi trusts and classified as trading totaled $112 million and $104 million at December 31, 2017 and 2016, respectively. D ECOMMISSIONING RUST ECURITIES Dominion Energy holds marketable equity and debt securities (classified as available-for-sale), Amortized Cost Total Unrealized Gains (1) Total Unrealized Losses (1) Fair (millions) At December 31, 2017 Marketable equity securities: U.S. $1,569 $1,857 $ — $3,426 Fixed income: Corporate debt instruments 430 15 (1 ) 444 Government securities 1,039 27 (5 ) 1,061 Common/collective trust funds 60 — — 60 Cost method investments 68 — — 68 Cash equivalents and other (2) 34 — — 34 Total $3,200 $1,899 $ (6 ) (3) $5,093 At December 31, 2016 Marketable equity securities: U.S. $1,449 $1,408 $ — $2,857 Fixed income: Corporate debt instruments 478 13 (4 ) 487 Government securities 978 22 (8) 992 Common/collective trust funds 67 — — 67 Cost method investments 69 — — 69 Cash equivalents and other (2) 12 — — 12 Total $3,053 $1,443 $(12 ) (3) $4,484 (1) Included in AOCI and the nuclear decommissioning trust regulatory liability as discussed in Note 2. (2) Includes pending sales of securities of $5 million and $9 million at December 31, 2017 and 2016, respectively. (3) The fair value of securities in an unrealized loss position was $565 million and $576 million at December 31, 2017 and 2016, respectively. The fair value of Dominion Energy’s marketable debt securities held in nuclear decommissioning trust funds at December 31, 2017 by contractual maturity is as follows: Amount (millions) Due in one year or less $ 151 Due after one year through five years 385 Due after five years through ten years 370 Due after ten years 659 Total $ 1,565 Presented below is selected information regarding Dominion Energy’s marketable equity and debt securities held in nuclear decommissioning trust funds: Year Ended December 31, 2017 2016 2015 (millions) Proceeds from sales $ 1,831 $ 1,422 $ 1,340 Realized gains (1) 166 128 219 Realized losses (1) 71 55 84 (1) Includes realized gains and losses recorded to the nuclear decommissioning trust regulatory liability as discussed in Note 2. Dominion Energy recorded other-than-temporary impairment losses on investments held in nuclear decommissioning trust funds as follows: Year Ended December 31, 2017 2016 2015 (millions) Total other-than-temporary impairment losses (1) $ 44 $ 51 $ 66 Losses recorded to the nuclear decomissioning trust regulatory liability (16 ) (16 ) (26 ) Losses recognized in other comprehensive income (before taxes) (5 ) (12 ) (9 ) Net impairment losses recognized in earnings $ 23 $ 23 $ 31 (1) Amounts include other-than-temporary impairment losses for debt securities of $5 million, $13 million and $9 million at December 31, 2017, 2016 and 2015, respectively. V IRGINIA OWER Virginia Power holds marketable equity and debt securities (classified as available-for-sale), Amortized Cost Total Gains (1) Total Losses (1) Fair (millions) At December 31, 2017 Marketable equity securities: U.S. $ 734 $831 $— $1,565 Fixed income: Corporate debt instruments 216 8 — 224 Government securities 482 13 (2 ) 493 Common/collective trust funds 27 — — 27 Cost method investments 68 — — 68 Cash equivalents and other (2) 22 — — 22 Total $1,549 $852 $(2 ) (3) $2,399 At December 31, 2016 Marketable equity securities: U.S. $ 677 $624 $— $1,301 Fixed income: Corporate debt instruments 274 6 (4 ) 276 Government securities 420 9 (2 ) 427 Common/collective trust funds 26 — — 26 Cost method investments 69 — — 69 Cash equivalents and other (2) 7 — — 7 Total $1,473 $639 $(6 ) (3) $2,106 (1) Included in AOCI and the nuclear decommissioning trust regulatory liability as discussed in Note 2. (2) Includes pending sales of securities of $6 million and $7 million at December 31, 2017 and 2016, respectively. (3) The fair value of securities in an unrealized loss position was $234 million and $287 million at December 31, 2017 and 2016, respectively. The fair value of Virginia Power’s marketable debt securities at December 31, 2017, by contractual maturity is as follows: Amount (millions) Due in one year or less $ 32 Due after one year through five years 165 Due after five years through ten years 199 Due after ten years 348 Total $744 Presented below is selected information regarding Virginia Power’s marketable equity and debt securities held in nuclear decommissioning trust funds. Year Ended December 31, 2017 2016 2015 (millions) Proceeds from sales $ 849 $ 733 $ 639 Realized gains (1) 75 63 110 Realized losses (1) 30 27 43 (1) Includes realized gains and losses recorded to the nuclear decommissioning trust regulatory liability as discussed in Note 2. Virginia Power recorded other-than-temporary impairment losses on investments held in nuclear decommissioning trust funds as follows: Year Ended December 31, 2017 2016 2015 (millions) Total other-than-temporary impairment losses (1) $ 20 $ 26 $ 36 Losses recorded to the nuclear decomissioning trust regulatory liability (16 ) (16 ) (26 ) Losses recognized in other comprehensive income (before taxes) (2 ) (7 ) (6 ) Net impairment losses recognized in earnings $ 2 $ 3 $ 4 (1) Amounts include other-than-temporary impairment losses for debt securities of $2 million, $8 million and $6 million at December 31, 2017, 2016 and 2015, respectively. Equity Method Investments D OMINION NERGY AND OMINION NERGY AS Investments that Dominion Energy and Dominion Energy Gas account for under the equity method of accounting are as follows: Company Ownership % Investment Balance Description As of December 31, 2017 2016 (millions) Dominion Energy Blue Racer 50 % $ 691 $ 677 Midstream gas and Iroquois 50 % (1) 311 316 Gas transmission system Atlantic Coast Pipeline 48 % 382 256 Gas transmission system Fowler Ridge 50 % 81 116 Wind-powered merchant NedPower 50 % — (2) 112 Wind-powered merchant Other various 79 84 Total $ 1,544 $ 1,561 Dominion Energy Gas Iroquois 24.07 % $ 95 $ 98 Gas transmission system Total $ 95 $ 98 (1) Comprised of Dominion Energy Midstream’s interest of 25.93% and Dominion Energy Gas’ interest of 24.07%. See Note 15 for more information. (2) Liability of $17 million associated with NedPower recorded to other deferred credits and other liabilities, on the Consolidated Balance Sheets as of December 31, 2017. See additional discussion of NedPower below. Dominion Energy’s equity earnings on its investments totaled $14 million, $111 million and $56 million in 2017, 2016 and 2015, respectively, included in other income in Dominion Energy’s Consolidated Statements of Income. Dominion Energy received distributions from these investments of $419 million, $104 million and $83 million in 2017, 2016 and 2015, respectively. As of December 31, 2017 and 2016, the carrying amount of Dominion Energy’s investments exceeded its share of underlying equity in net assets by $249 million and $260 million, respectively. These differences are comprised at both December 31, 2017 and 2016 of $176 million, reflecting equity method goodwill that is not being amortized and at December 31, 2017 and 2016, of $73 million and $84 million related to basis differences from Dominion Energy’s investments in Blue Racer and wind projects, which are being amortized over the useful lives of the underlying assets, and in Atlantic Coast Pipeline, which is being amortized over the term of the credit facility. Dominion Energy Gas’ equity earnings on its investment totaled $21 million in 2017 and 2016 and $23 million in 2015. Dominion Energy Gas received distributions from its investment of $24 million, $22 million and $28 million in 2017, 2016 and 2015, respectively. As of December 31, 2017 and 2016, the carrying amount of Dominion Energy Gas’ investment exceeded its share of underlying equity in net assets by $8 million. The difference reflects equity method goodwill and is not being amortized. In May 2016, Dominion Energy Gas sold 0.65% of the noncontrolling partnership interest in Iroquois to TransCanada for approximately $7 million, which resulted in a $5 million ($3 million after-tax) D OMINION NERGY B LUE ACER In December 2012, Dominion Energy formed a joint venture with Caiman to provide midstream services to natural gas producers operating in the Utica Shale region in Ohio and portions of Pennsylvania. Blue Racer is an equal partnership between Dominion Energy and Caiman, with Dominion Energy contributing midstream assets and Caiman contributing private equity capital. In December 2016, Dominion Energy Gas repurchased a portion of the Western System from Blue Racer for $10 million, which is included in property, plant and equipment in Dominion Energy Gas’ Consolidated Balance Sheets. A TLANTIC OAST IPELINE In September 2014, Dominion Energy, along with Duke and Southern Company Gas, announced the formation of Atlantic Coast Pipeline. The Atlantic Coast Pipeline partnership agreement includes provisions to allow Dominion Energy an option to purchase additional ownership interest in Atlantic Coast Pipeline to maintain a leading ownership percentage. In October 2016, Dominion Energy purchased an additional 3% membership interest in Atlantic Coast Pipeline from Duke for $14 million. As of December 31, 2017, the members hold the following membership interests: Dominion Energy, 48%; Duke, 47%; and Southern Company Gas, 5%. Atlantic Coast Pipeline is focused on constructing an approximately 600-mile 20-year 20-year DETI provides services to Atlantic Coast Pipeline which totaled $129 million, $95 million and $74 million in 2017, 2016 and 2015, respectively, included in operating revenue in Dominion Energy and Dominion Energy Gas’ Consolidated Statements of Income. Amounts receivable related to these services were $12 million and $10 million at December 31, 2017 and 2016, respectively, composed entirely of accrued unbilled revenue, included in other receivables in Dominion Energy and Dominion Energy Gas’ Consolidated Balance Sheets. In October 2017, Dominion Energy entered into a guarantee agreement to support a portion of Atlantic Coast Pipeline’s obligation under its credit facility. See Note 22 for more information. Dominion Energy contributed $310 million, $184 million and $38 million during 2017, 2016 and 2015, respectively, to Atlantic Coast Pipeline. Dominion Energy received distributions of $270 million in 2017 from Atlantic Coast Pipeline. No distributions were received in 2016 or 2015. F OWLER IDGE ED OWER In the fourth quarter of 2017, Dominion Energy recorded a charge of $126 million ($76 million after-tax) As a result of the impairment recorded by NedPower, Dominion Energy evaluated its equity method investment in Fowler Ridge, a similar wind-powered merchant generation facility, determined its fair value was other than-temporarily impaired and recorded an impairment charge of $32 million ($20 million after-tax)

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	N OTE ROPERTY LANT AND QUIPMENT Major classes of property, plant and equipment and their respective balances for the Companies are as follows: At December 31, 2017 2016 (millions) Dominion Energy Utility: Generation $ 17,602 $ 17,147 Transmission 15,335 14,315 Distribution 17,408 16,381 Storage 2,887 2,814 Nuclear fuel 1,599 1,537 Gas gathering and processing 219 216 Oil and gas 1,720 1,652 General and other 1,514 1,450 Plant under construction 7,765 6,254 Total utility 66,049 61,766 Nonutility: Merchant generation-nuclear 1,452 1,419 Merchant generation-other 4,992 4,149 Nuclear fuel 968 897 Gas gathering and processing 630 619 Other-including plant under construction 732 706 Total nonutility 8,774 7,790 Total property, plant and equipment $ 74,823 $ 69,556 Virginia Power Utility: Generation $ 17,602 $ 17,147 Transmission 8,332 7,871 Distribution 11,151 10,573 Nuclear fuel 1,599 1,537 General and other 794 745 Plant under construction 2,840 2,146 Total utility 42,318 40,019 Nonutility-other 11 11 Total property, plant and equipment $ 42,329 $ 40,030 Dominion Energy Gas Utility: Transmission $ 4,732 $ 4,231 Distribution 3,267 3,019 Storage 1,688 1,627 Gas gathering and processing 202 198 General and other 216 184 Plant under construction 293 448 Total utility 10,398 9,707 Nonutility: Gas gathering and processing 630 $ 619 Other-including plant under construction 145 149 Total nonutility 775 768 Total property, plant and equipment $ 11,173 $ 10,475 D OMINION NERGY AND IRGINIA OWER Jointly-Owned Power Stations Dominion Energy’s and Virginia Power’s proportionate share of jointly-owned power stations at December 31, 2017 is as follows: Bath County Pumped Storage Station (1) North Anna Units 1 and 2 (1) Clover Power Station (1) Millstone Unit 3 (2) (millions, except percentages) Ownership interest 60 % 88.4 % 50 % 93.5 % Plant in service $ 1,059 $ 2,504 $ 589 $ 1,217 Accumulated depreciation (612 ) (1,263 ) (231 ) (381 ) Nuclear fuel — 745 — 552 Accumulated amortization of nuclear fuel — (607 ) — (427 ) Plant under construction 2 92 6 68 (1) Units jointly owned by Virginia Power. (2) Unit jointly owned by Dominion Energy. The co-owners Acquisition of Solar Projects In September 2017, Virginia Power entered into agreements to acquire two solar development projects in North Carolina. The first acquisition is expected to close prior to the project commencing commercial operations, which is expected by the end of 2018, and cost approximately $140 million once constructed, including the initial acquisition cost. The second acquisition is expected to close prior to the project commencing commercial operations, which is expected by the end of 2019, and cost approximately $140 million once constructed, including the initial acquisition cost. The projects are expected to generate approximately 155 MW combined. Virginia Power anticipates claiming federal investment tax credits on these solar projects. Assignment of Tower Rental Portfolio Virginia Power rents space on certain of its electric transmission towers to various wireless carriers for communications antennas and other equipment. In March 2017, Virginia Power sold its rental portfolio to Vertical Bridge Towers II, LLC for $91 million in cash. The proceeds are subject to Virginia Power’s FERC-regulated tariff, under which it is required to return half of the proceeds to customers. Virginia Power recognized $11 million during 2017, with the remaining $35 million to be recognized ratably through 2023. D OMINION NERGY AND OMINION NERGY AS Assignments of Shale Development Rights In December 2013, Dominion Energy Gas closed on agreements with two natural gas producers to convey over time approximately 100,000 acres of Marcellus Shale development rights underneath several of its natural gas storage fields. The agreements provide for payments to Dominion Energy Gas, subject to customary adjustments, of approximately $200 million over a period of nine years, and an overriding royalty interest in gas produced from the acreage. In 2013, Dominion Energy Gas received approximately $100 million in cash proceeds. In 2014, Dominion Energy Gas received $16 million in additional cash proceeds resulting from post-closing adjustments. In March 2015, Dominion Energy Gas and one of the natural gas producers closed on an amendment to the agreement, which included the immediate conveyance of approximately 9,000 acres of Marcellus Shale development rights and a two-year after-tax) after-tax) after-tax) after-tax) after-tax) In November 2014, Dominion Energy Gas closed an agreement with a natural gas producer to convey over time approximately 24,000 acres of Marcellus Shale development rights underneath one of its natural gas storage fields. The agreement provided for payments to Dominion Energy Gas, subject to customary adjustments, of approximately $120 million over a period of four years, and an overriding royalty interest in gas produced from the acreage. In November 2014, Dominion Energy Gas closed on the agreement and received proceeds of $60 million associated with an initial conveyance of approximately 12,000 acres. In connection with that agreement, in 2016, Dominion Energy Gas conveyed a 50% interest in approximately 4,000 acres of Marcellus Shale development rights and received proceeds of $10 million and an overriding royalty interest in gas produced from the acreage. These transactions resulted in a $10 million ($6 million after-tax) after-tax) after-tax) In March 2015, Dominion Energy Gas conveyed to a natural gas producer approximately 11,000 acres of Marcellus Shale development rights underneath one of its natural gas storage fields and received proceeds of $27 million and an overriding royalty interest in gas produced from the acreage. This transaction resulted in a $27 million ($16 million after-tax) In September 2015, Dominion Energy Gas closed on an agreement with a natural gas producer to convey approximately 16,000 acres of Utica and Point Pleasant Shale development rights underneath one of its natural gas storage fields. The agreement provided for a payment to Dominion Energy Gas, subject to customary adjustments, of $52 million and an overriding royalty interest in gas produced from the acreage. In September 2015, Dominion Energy Gas received proceeds of $52 million associated with the conveyance of the acreage, resulting in a $52 million ($29 million after-tax) D OMINION NERGY Sale of Certain Retail Energy Marketing Assets In October 2017, Dominion Energy entered into an agreement to sell certain assets associated with its nonregulated retail energy marketing operations for total consideration of $143 million, subject to customary approvals and certain adjustments. In December 2017, the first phase of the agreement closed for $79 million, which resulted in the recognition of a $78 million ($48 million after-tax) after-tax) ten-year

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	N OTE OODWILL AND NTANGIBLE SSETS Goodwill The changes in Dominion Energy’s and Dominion Energy Gas’ carrying amount and segment allocation of goodwill are presented below: Power Gas Power Corporate and Other (1) Total (millions) Dominion Energy Balance at December 31, 2015 (2) $1,422 $ 946 $926 $— $3,294 Dominion Energy Questar Combination — 3,105 (3) — — 3,105 Balance at December 31, 2016 (2) $1,422 $4,051 $926 $— $6,399 Dominion Energy Questar Combination — 6 (3) — — 6 Balance at December 31, 2017 (2) $1,422 $4,057 $926 $— $6,405 Dominion Energy Gas Balance at December 31, 2015 (2) $ — $ 542 $ — $— $ 542 No events affecting goodwill — — — — — Balance at December 31, 2016 (2) $ — $ 542 $ — $— $ 542 No events affecting goodwill — — — — — Balance at December 31, 2017 (2) $ — $ 542 $ — $— $ 542 (1) Goodwill recorded at the Corporate and Other segment is allocated to the primary operating segments for goodwill impairment testing purposes. (2) Goodwill amounts do not contain any accumulated impairment losses. (3) See Note 3. Other Intangible Assets The Companies’ other intangible assets are subject to amortization over their estimated useful lives. Dominion Energy’s amortization expense for intangible assets was $80 million, $73 million and $78 million for 2017, 2016 and 2015, respectively. In 2017, Dominion Energy acquired $147 million of intangible assets, primarily representing software and right-of-use 2017 2016 At December 31, Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization (millions) Dominion Energy Software, licenses and other $1,043 $358 $955 $337 Virginia Power Software, licenses and other $ 347 $114 $326 $101 Dominion Energy Gas Software, licenses and other $ 165 $ 56 $147 $ 49 Annual amortization expense for these intangible assets is estimated to be as follows: 2018 2019 2020 2021 2022 (millions) Dominion Energy $ 78 $ 68 $ 56 $ 43 $ 37 Virginia Power $ 30 $ 26 $ 20 $ 13 $ 9 Dominion Energy Gas $ 13 $ 13 $ 12 $ 11 $ 10

Regulatory Assets and Liabiliti

Regulatory Assets and Liabilities	12 Months Ended
	Dec. 31, 2017
Regulated Operations [Abstract]
Regulatory Assets and Liabilities	N OTE EGULATORY SSETS ND IABILITIES Regulatory assets and liabilities include the following: At December 31, 2017 2016 (millions) Dominion Energy Regulatory assets: Deferred rate adjustment clause costs (1) $ 70 $ 63 Deferred nuclear refueling outage costs (2) 54 71 Unrecovered gas costs (3) 38 19 Deferred cost of fuel used in electric generation (4) 23 — Other 109 91 Regulatory assets-current 294 244 Unrecognized pension and other postretirement benefit costs (5) 1,336 1,401 Deferred rate adjustment clause costs (1) 401 329 Derivatives (6) 223 174 PJM transmission rates (7) 222 192 Utility reform legislation (8) 147 99 Income taxes recoverable through future rates (9) 32 123 Other 119 155 Regulatory assets-noncurrent 2,480 2,473 Total regulatory assets $ 2,774 $ 2,717 Regulatory liabilities: Provision for future cost of removal and AROs (10) $ 101 $ — PIPP (11) 20 28 Deferred cost of fuel used in electric generation (4) 8 61 Other 64 74 Regulatory liabilities-current (12) 193 163 Income taxes refundable through future rates (13) 4,058 — Provision for future cost of removal and AROs (10) 1,384 1,427 Nuclear decommissioning trust (14) 1,121 902 Derivatives (6) 69 69 Other 284 224 Regulatory liabilities-noncurrent 6,916 2,622 Total regulatory liabilities $ 7,109 $ 2,785 Virginia Power Regulatory assets: Deferred rate adjustment clause costs (1) $ 56 $ 51 Deferred nuclear refueling outage costs (2) 54 71 Deferred cost of fuel used in electric generation (4) 23 — Other 72 57 Regulatory assets-current 205 179 Deferred rate adjustment clause costs (1) 312 246 PJM transmission rates (7) 222 192 Derivatives (6) 190 133 Income taxes recoverable through future rates (9) — 76 Other 86 123 Regulatory assets-noncurrent 810 770 Total regulatory assets $ 1,015 $ 949 Regulatory liabilities: Provision for future cost of removal (10) $ 80 $ — Deferred cost of fuel used in electric generation (4) 8 61 Other 39 54 Regulatory liabilities-current (12) 127 115 Income taxes refundable through future rates (13) 2,581 — Nuclear decommissioning trust (14) 1,121 902 Provision for future cost of removal (10) 915 946 Derivatives (6) 69 69 Other 74 45 Regulatory liabilities-noncurrent 4,760 1,962 Total regulatory liabilities $ 4,887 $ 2,077 Dominion Energy Gas Regulatory assets: Deferred rate adjustment clause costs (1) $ 14 $ 12 Unrecovered gas costs (3) 8 12 Other 4 2 Regulatory assets-current (15) 26 26 Unrecognized pension and other postretirement benefit costs (5) 258 358 Utility reform legislation (8) 147 99 Deferred rate adjustment clause costs (1) 89 79 Income taxes recoverable through future rates (9) — 23 Other 17 18 Regulatory assets-noncurrent 511 577 Total regulatory assets $ 537 $ 603 Regulatory liabilities: PIPP (11) $ 20 $ 28 Provision for future cost of removal and AROs (10) 13 — Other 5 7 Regulatory liabilities-current (12) 38 35 Income taxes refundable through future rates (13) 998 — Provision for future cost of removal and AROs (10) 160 174 Other 69 45 Regulatory liabilities-noncurrent 1,227 219 Total regulatory liabilities $ 1,265 $ 254 (1) Primarily reflects deferrals under the electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects for Virginia Power and deferrals of costs associated with certain current and prospective rider projects for Dominion Energy Gas. See Note 13 for more information. (2) Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months. (3) Reflects unrecovered gas costs at regulated gas operations, which are recovered through filings with the applicable regulatory authority. (4) Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Dominion Energy’s and Virginia Power’s generation operations. See Note 13 for more information. (5) Represents unrecognized pension and other postretirement employee benefit costs expected to be recovered through future rates generally over the expected remaining service period of plan participants by certain of Dominion Energy’s and Dominion Energy Gas’ rate-regulated subsidiaries. (6) As discussed under Derivative Instruments in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers. (7) Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information. (8) Ohio legislation under House Bill 95, which became effective in September 2011. This law updates natural gas legislation by enabling gas companies to include more up-to-date (9) Amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity and depreciation of property, plant and equipment for which deferred income taxes were not recognized for ratemaking purposes, including amounts attributable to tax rate changes. See below for discussion of the 2017 Tax Reform Act. (10) Rates charged to customers by the Companies’ regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement. (11) Under PIPP, eligible customers can make reduced payments based on their ability to pay. The difference between the customer’s total bill and the PIPP plan amount is deferred and collected or returned annually under the PIPP rate adjustment clause according to East Ohio tariff provisions. See Note 13 for more information. (12) Current regulatory liabilities are presented in other current liabilities in the Consolidated Balance Sheets of the Companies. (13) Amounts recorded to pass the effect of reduced income tax rates from the 2017 Tax Reform Act to customers in future periods, which will reverse at the weighted average tax rate that was used to build the reserves over the remaining book life of the property, net of amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity. (14) Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon) for the future decommissioning of Virginia Power’s utility nuclear generation stations, in excess of the related AROs. (15) Current regulatory assets are presented in other current assets in the Consolidated Balance Sheets of Dominion Energy Gas. At December 31, 2017, $390 million of Dominion Energy’s, $273 million of Virginia Power’s and $11 million of Dominion Energy Gas’ regulatory assets represented past expenditures on which they do not currently earn a return. With the exception of the $222 million PJM transmission cost allocation matter, the majority of these expenditures are expected to be recovered within the next two years.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2017
Regulated Operations [Abstract]
Regulatory Matters	N OTE EGULATORY ATTERS Regulatory Matters Involving Potential Loss Contingencies As a result of issues generated in the ordinary course of business, the Companies are involved in various regulatory matters. Certain regulatory matters may ultimately result in a loss; however, as such matters are in an initial procedural phase, involve uncertainty as to the outcome of pending reviews or orders, and/or involve significant factual issues that need to be resolved, it is not possible for the Companies to estimate a range of possible loss. For matters for which the Companies cannot estimate a range of possible loss, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the regulatory process such that the Companies are able to estimate a range of possible loss. For regulatory matters for which the Companies are able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any estimated range is based on currently available information, involves elements of judgment and significant uncertainties and may not represent the Companies’ maximum possible loss exposure. The circumstances of such regulatory matters will change from time to time and actual results may vary significantly from the current estimate. For current matters not specifically reported below, management does not anticipate that the outcome from such matters would have a material effect on the Companies’ financial position, liquidity or results of operations. FERC—E LECTRIC Under the Federal Power Act, FERC regulates wholesale sales and transmission of electricity in interstate commerce by public util-ities. Dominion Energy’s merchant generators sell electricity in the PJM, MISO, CAISO and ISO-NE Rates In April 2008, FERC granted an application for Virginia Power’s electric transmission operations to establish a forward-looking formula rate mechanism that updates transmission rates on an annual basis and approved an ROE of 11.4%, effective as of January 1, 2008. The formula rate is designed to recover the expected revenue requirement for each calendar year and is updated based on actual costs. The FERC-approved formula method, which is based on projected costs, allows Virginia Power to earn a current return on its growing investment in electric transmission infrastructure. In March 2010, ODEC and North Carolina Electric Membership Corporation filed a complaint with FERC against Virginia Power claiming, among other issues, that the incremental costs of undergrounding certain transmission line projects were unjust, unreasonable and unduly discriminatory or preferential and should be excluded from Virginia Power’s transmission formula rate. A settlement of the other issues raised in the complaint was approved by FERC in May 2012. In March 2014, FERC issued an order excluding from Virginia Power’s transmission rates for wholesale transmission customers located outside Virginia the incremental costs of undergrounding certain transmission line projects. FERC found it is not just and reasonable for non-Virginia In October 2017, FERC issued an order determining the calculation of the incremental costs of undergrounding the transmission projects and affirming that the costs are to be recovered from the wholesale transmission customers with loads located in Virginia. FERC directed Virginia Power to rebill all wholesale transmission customers retroactively to March 2010 within 30 days of when the proceeding becomes final and no longer subject to rehearing. In November 2017, Virginia Power, North Carolina Electric Membership Corporation and the wholesale transmission customers filed petitions for rehearing. While Virginia Power cannot predict the outcome of the matter, it is not expected to have a material effect on results of operations. PJM Transmission Rates In April 2007, FERC issued an order regarding its transmission rate design for the allocation of costs among PJM transmission customers, including Virginia Power, for transmission service provided by PJM. For new PJM-planned In August 2009, the court issued its decision affirming the FERC order with regard to the existing facilities, but remanded to FERC the issue of the cost allocation associated with the new facilities 500 kV and above for further consideration by FERC. On remand, FERC reaffirmed its earlier decision to allocate the costs of new facilities 500 kV and above according to the customer’s share of the region’s load. A number of parties filed appeals of the order to the U.S. Court of Appeals for the Seventh Circuit. In June 2014, the court again remanded the cost allocation issue to FERC. In December 2014, FERC issued an order setting an evidentiary hearing and settlement proceeding regarding the cost allocation issue. The hearing only concerns the costs of new facilities approved by PJM prior to February 1, 2013. Transmission facilities approved after February 1, 2013 are allocated on a hybrid cost allocation method approved by FERC and not subject to any court review. In June 2016, PJM, the PJM transmission owners and state commissions representing substantially all of the load in the PJM market submitted a settlement to FERC to resolve the outstanding issues regarding this matter. Under the terms of the settlement, Virginia Power would be required to pay approximately $200 million to PJM over the next 10 years. Although the settlement agreement has not been accepted by FERC, and the settlement is opposed by a small group of parties to the proceeding, Virginia Power believes it is probable it will be required to make payment as an outcome of the settlement. Accordingly, as of December 31, 2017, Virginia Power has a contingent liability of $231 million in other deferred credits and other liabilities, which is offset by a $222 million regulatory asset for the amount that will be recovered through retail rates in Virginia. FERC—G AS In July 2017, FERC audit staff communicated to DETI that it had substantially completed an audit of DETI’s compliance with the accounting and reporting requirements of FERC’s Uniform System of Accounts and provided a description of matters and preliminary recommendations. In November 2017, the FERC audit staff issued its audit report which could have the potential to result in adjustments which could be material to Dominion Energy and Dominion Energy Gas’ results of operations. In December 2017, DETI provided its response to the audit report. DETI requested FERC review of contested findings and submitted its plan for compliance with the uncontested portions of the report. In connection with one uncontested issue, DETI recognized a charge of $15 million ($9 million after-tax) write-off 2017 T AX EFORM CT Subsequent to the enactment of the 2017 Tax Reform Act, the Companies’ state regulators issued orders requesting that public utilities evaluate the total tax impact on the entity’s cost of service and accrue a regulatory liability attributable to the benefits of the reduction in the corporate income tax rate. Certain of the orders requested that the public utilities submit a response to the state regulatory commissions detailing the total tax impact on the utility’s cost of service. Virginia Power submitted a response to the North Carolina Commission detailing the impact of the 2017 Tax Reform Act on base non-fuel cost of service and Virginia Power’s excess deferred income taxes clarifying that the amounts have been deferred to a regulatory liability. Questar Gas submitted a response to the Utah Commission detailing the impact of the 2017 Tax Reform Act on base rates and the infrastructure rider, and proposing that the benefits be passed back to customers. These filings are pending. Dominion Energy plans to respond to the remaining state regulatory commissions in accordance with the due dates on the issued orders. The Companies will begin to reserve the impacts of the cost of service reduction as a regulatory liability beginning in 2018 until the rates are reset. To date, the FERC has not issued guidance on how and when to reflect the impacts of the 2017 Tax Reform Act in customer rates. The Companies have recorded a reasonable estimate of net income taxes refundable through future rates in the jurisdictions in which they operate. Through actions by FERC or state regulators the estimates may be subject to changes that could have a material impact on the Companies’ results of operations, financial condition and/or cash flows. Other Regulatory Matters E LECTRIC EGULATION IN IRGINIA The Regulation Act enacted in 2007 instituted a cost-of-service The Regulation Act authorizes stand-alone rate adjustment clauses for recovery of costs for new generation projects, FERC-approved transmission costs, underground distribution lines, environmental compliance, conservation and energy efficiency programs and renewable energy programs, and also contains statutory provisions directing Virginia Power to file annual fuel cost recovery cases with the Virginia Commission. As amended, it provides for enhanced returns on capital expenditures on specific newly-proposed generation projects. If the Virginia Commission’s future rate decisions, including actions relating to Virginia Power’s rate adjustment clause filings, differ materially from Virginia Power’s expectations, it may adversely affect its results of operations, financial condition and cash flows. Regulation Act Legislation In February 2015, the Virginia Governor signed legislation into law which will keep Virginia Power’s base rates unchanged until at least December 1, 2022. In addition, no biennial reviews will be conducted by the Virginia Commission for the five successive 12-month US-2 In February 2016, certain industrial customers of APCo petitioned the Virginia Commission to issue a declaratory judgment that Virginia legislation enacted in 2015 keeping APCo’s base rates unchanged until at least 2020 (and Virginia Power’s base rates unchanged until at least 2022) is unconstitutional, and to require APCo to make biennial review filings in 2016 and 2018. Virginia Power intervened to support the constitutionality of this legislation. In July 2016, the Virginia Commission held in a divided opinion that this legislation is constitutional, and the industrial customers appealed this order to the Supreme Court of Virginia. In November 2016, the Supreme Court of Virginia granted the appeal as a matter of right and consolidated it for oral argument with other similar appeals from the Virginia Commission’s order. In September 2017, the Supreme Court of Virginia affirmed that the legislation is constitutional. In March 2017, as required by Regulation Act legislation enacted in February 2015, Virginia Power filed an application for the Virginia Commission to determine the general ROE for Virginia Power’s non-transmission 2015 Biennial Review In November 2015, the Virginia Commission issued the 2015 Biennial Review Order. After deciding several contested regulatory earnings adjustments, the Virginia Commission ruled that Virginia Power earned on average an ROE of approximately 10.89% on its generation and distribution services for the combined 2013 and 2014 test periods. Because this ROE was more than 70 basis points above Virginia Power’s authorized ROE of 10.0%, the Virginia Commission ordered that approximately $20 million in excess earnings be credited to customer bills based on usage in 2013 and 2014 over a six-month Virginia Fuel Expenses In May 2017, Virginia Power submitted its annual fuel factor to the Virginia Commission to recover an estimated $1.6 billion in Virginia jurisdictional projected fuel expenses for the rate year beginning July 1, 2017. Virginia Power’s proposed fuel rate represented a fuel revenue increase of $279 million when applied to projected kilowatt-hour sales for the period July 1, 2017 to June 30, 2018. In June 2017, the Virginia Commission approved Virginia Power’s proposed fuel rate. Solar Facility Projects In February 2017, Virginia Power received approval from the Virginia Commission for a CPCN to construct and operate the Remington solar facility and related distribution interconnection facilities. The 20 MW facility began operations in October 2017 at a total cost of $45 million, excluding financing costs. The facility is the subject of a public-private partnership whereby the Commonwealth of Virginia, a non-jurisdictional In March 2017, Virginia Power received Virginia Commission approval for a CPCN to construct and operate the Oceana solar facility and related distribution interconnection facilities. The 18 MW facility began operations in December 2017 at a total cost of $40 million, excluding financing costs. The facility is the subject of a public-private partnership whereby the Commonwealth of Virginia, a non-jurisdictional Rate Adjustment Clauses Below is a discussion of significant riders associated with various Virginia Power projects: • The Virginia Commission previously approved Rider T1 concerning transmission rates. In May 2017, Virginia Power proposed a $625 million total revenue requirement consisting of $490 million for the transmission component of Virginia Power’s base rates and $135 million for Rider T1. This total revenue requirement represents a $55 million decrease versus the revenues to be produced during the rate year under current rates. In July 2017, the Virginia Commission approved the proposed total revenue requirement, including Rider T1, subject to true-up, • The Virginia Commission previously approved Rider S in conjunction with the Virginia City Hybrid Energy Center. In February 2017, the Virginia Commission approved a $243 million revenue requirement, subject to true-up, • The Virginia Commission previously approved Rider W in conjunction with Warren County. In February 2017, the Virginia Commission approved a $121 million revenue requirement, subject to true-up, • The Virginia Commission previously approved Rider R in conjunction with Bear Garden. In February 2017, the Virginia Commission approved a $72 million revenue requirement, subject to true-up, true-up, • The Virginia Commission previously approved Rider B in conjunction with the conversion of three power stations to biomass. In February 2017, the Virginia Commission approved a $27 million revenue requirement for the rate year beginning April 1, 2017. It also established an 11.4% ROE effective April 1, 2017. In June 2017, Virginia Power proposed a $42 million revenue requirement for the rate year beginning April 1, 2018, which represents a $15 million increase over the previous year. This case is pending. • The Virginia Commission previously approved Rider U in conjunction with cost recovery to move certain electric distribution facilities underground as authorized by prior Virginia legislation. In September 2017, the Virginia Commission approved a total $22 million annual revenue requirement effective October 1, 2017, using a 9.4% ROE, and a total capital investment of $40 million for second phase conversions. • The Virginia Commission previously approved Riders C1A and C2A in connection with cost recovery for DSM programs. In June 2017, the Virginia Commission approved a $28 million revenue requirement, subject to true-up, • The Virginia Commission previously approved Rider BW in conjunction with Brunswick County. In April 2017, the Virginia Commission established a 10.4% ROE for Rider BW effective September 1, 2017. In June 2017, it approved a $127 million revenue requirement, subject to true-up, • The Virginia Commission previously approved Rider US-2 US-2 true-up, • The Virginia Commission previously approved Rider GV in conjunction with Greensville County. In February 2017, the Virginia Commission approved an $82 million revenue requirement, subject to true-up, Electric Transmission Projects In November 2013, the Virginia Commission issued an order granting Virginia Power a CPCN to construct approximately 7 miles of new overhead 500 kV transmission line from the existing Surry switching station in Surry County to a new Skiffes Creek switching station in James City County, and approximately 20 miles of new 230 kV transmission line in James City County, York County, and the City of Newport News from the proposed new Skiffes Creek switching station to Virginia Power’s existing Whealton substation in the City of Hampton. As of July 2017, Virginia Power has received all major required permits and approvals and is proceeding with construction of the project. In connection with the receipt of the permit from the U.S. Army Corps of Engineers in July 2017, Virginia Power was required to make payments totaling approximately $90 million to fund improvements to historical and cultural resources near the project. Accordingly, in July 2017, Virginia Power recorded an increase to property, plant and equipment and a corresponding liability for these payment obligations. Through December 31, 2017, Virginia Power had made $90 million of such payments. Also in July 2017, the National Parks Conservation Association filed a lawsuit in U.S. District Court for the D.C. Circuit seeking to set aside the permit granted by the U.S. Army Corps of Engineers for the project and requested a preliminary injunction against the permit. In August 2017, the National Trust for Historic Preservation and Preservation Virginia filed a similar lawsuit in U.S. District Court for the D.C. Circuit. In October 2017, the preliminary injunction requests were denied. These lawsuits are pending. In November 2015, Virginia Power filed an application with the Virginia Commission for a CPCN to convert an existing transmission line to 230 kV in Prince William County, Virginia, and Loudoun County, Virginia, and to construct and operate a new approximately five mile overhead 230 kV double circuit transmission line between a tap point near the Gainesville substation and a new to-be-constructed rights-of-way. In November 2015, Virginia Power filed an application with the Virginia Commission for a CPCN to construct and operate in multiple Virginia counties an approximately 38 mile overhead 230 kV transmission line between the Remington and Gordonsville substations, along with associated facilities. In August 2017, the Virginia Commission granted a CPCN for the project. The total estimated cost of the project is approximately $105 million. In March 2016, Virginia Power filed an application with the Virginia Commission for a CPCN to rebuild and operate in multiple Virginia counties approximately 33 miles of the existing 500 kV transmission line between the Cunningham switching station and the Dooms substation, along with associated station work. In May 2017, the Virginia Commission granted a CPCN to construct and operate the project. The total estimated cost of the project is approximately $60 million. In August 2016, Virginia Power filed an application with the Virginia Commission for a CPCN to rebuild and operate in multiple Virginia counties approximately 28 miles of the existing 500 kV transmission line between the Carson switching station and a terminus located near the Rogers Road switching station under construction in Greensville County, Virginia, along with associated work at the Carson switching station. In March 2017, the Virginia Commission granted a CPCN to construct and operate the project. The total estimated cost of the project is approximately $55 million. In January 2017, Virginia Power filed an application with the Virginia Commission for a CPCN to rebuild and rearrange its Idylwood substation in Fairfax County, Virginia. In September 2017, the Virginia Commission granted a CPCN for the project. The total estimated cost of the project is approximately $110 million. In June 2017, Virginia Power filed an application with the Virginia Commission for a CPCN to rebuild and operate in Prince William County, Virginia, approximately 9 miles of existing 115 kV transmission lines between Possum Point Switching Station and NOVEC’s Smoketown delivery point, utilizing 230 kV design on the majority of the route, for total estimated cost of approximately $20 million. In February 2018, the Virginia Commission granted a CPCN for the project. In September 2017, Virginia Power filed an application with the Virginia Commission for a CPCN to rebuild and operate in Augusta County, Virginia approximately 18 miles of the existing 500 kV transmission line between the Dooms substation and the Valley substation, along with associated substation work, for a total estimated cost of approximately $65 million. This case is pending. In November 2017, Virginia Power filed an application with the Virginia Commission for a CPCN to build and operate in Fairfax County, Virginia approximately 4 miles of 230 kV transmission line between the Idylwood and Tysons substations, along with associated substation work. The total estimated cost of the project is approximately $125 million. This case is pending. In February 2016, Virginia Power filed an application with the Virginia Commission for a CPCN to rebuild and operate in Lancaster County, Virginia and Middlesex County, Virginia and across the Rappahannock River, approximately 2 miles of existing 115 kV transmission lines between Harmony Village Substation and White Stone Substation. In December 2017, the Virginia Commission granted a CPCN for the project to be constructed under the Rappahannock River. The total estimated cost of the project is approximately $85 million. North Anna Virginia Power is considering the construction of a third nuclear unit at a site located at North Anna nuclear power station. If Virginia Power decides to build a new unit, it would require a COL from the NRC, approval of the Virginia Commission and certain environmental permits and other approvals. In June 2017, the NRC issued the COL. Virginia Power has not yet committed to building a new nuclear unit at North Anna nuclear power station. Requests by BREDL for a contested NRC hearing on Virginia Power’s COL application were dismissed, and in September 2016, the U.S. Court of Appeals for the D.C. Circuit dismissed with prejudice petitions for judicial review that BREDL and other organizations had filed challenging the NRC’s reliance on a rule generically assessing the environmental impacts of continued onsite storage of spent nuclear fuel in various licensing proceedings, including Virginia Power’s COL proceeding. This dismissal followed the Court’s June 2016 decision in New York v. NRC, upholding the NRC’s continued storage rule and August 2016 denial of requests for rehearing en banc. Therefore, the contested portion of the COL proceeding was closed. The NRC is required to conduct a hearing in all COL proceedings. This mandatory NRC hearing was held in March 2017, was uncontested and the resulting NRC decision authorized issuance of the COL. In August 2016, Virginia Power received a 60-day N ORTH AROLINA EGULATION In August 2017, Virginia Power submitted its annual filing to the North Carolina Commission to adjust the fuel component of its electric rates. Virginia Power proposed a total $15 million increase to the fuel component of its electric rates for the rate year beginning January 1, 2018. In January 2018, the North Carolina Commission approved Virginia Power’s proposed fuel charge adjustment. O HIO EGULATION PIR Program In 2008, East Ohio began PIR, aimed at replacing approximately 25% of its pipeline system. In March 2015, East Ohio filed an application with the Ohio Commission requesting approval to extend the PIR program for an additional five years and to increase the annual capital investment, with corresponding increases in the annual rate-increase caps. In September 2016, the Ohio Commission approved a stipulation filed jointly by East Ohio and the Staff of the Ohio Commission to settle East Ohio’s pending application. As requested, the PIR program and associated cost recovery will continue for another five-year term, calendar years 2017 through 2021, and East Ohio will be permitted to increase its annual capital expenditures to $200 million by 2018 and 3% per year thereafter subject to the cost recovery rate increase caps proposed by East Ohio. In April 2017, the Ohio Commission approved East Ohio’s application to adjust the PIR cost recovery rates for 2016 costs. The filing reflects gross plant investment for 2016 of $188 million, cumulative gross plant investment of $1.2 billion and a revenue requirement of $157 million. AMR Program In 2007, East Ohio began installing automated meter reading technology for its 1.2 million customers in Ohio. The AMR program approved by the Ohio Commission was completed in 2012. Although no further capital investment will be added, East Ohio is approved to recover depreciation, property taxes, carrying charges and a return until East Ohio has another rate case. In April 2017, the Ohio Commission approved East Ohio’s application to adjust its AMR cost recovery rate for 2016 costs. The filing reflects a revenue requirement of approximately $6 million. PIPP Plus Program Under the Ohio PIPP Plus Program, eligible customers can make reduced payments based on their ability to pay their bill. The difference between the customer’s total bill and the PIPP amount is deferred and collected under the PIPP Rider in accordance with the rules of the Ohio Commission. In July 2017, East Ohio’s annual update of the PIPP Rider was automatically approved by the Ohio Commission after a 45-day UEX Rider East Ohio has approval for a UEX Rider through which it recovers the bad debt expense of most customers not participating in the PIPP Plus Program. The UEX Rider is adjusted annually to achieve dollar for dollar recovery of East Ohio’s actual write-offs of uncollectible amounts. In September 2017, the Ohio Commission approved East Ohio’s application requesting approval of its UEX Rider to reflect a refund of over-recovered accumulated bad debt expense of approximately $12 million as of March 31, 2017, and recovery of prospective net bad debt expense projected to total approximately $22 million for the twelve-month period from April 2017 to March 2018. Ohio Legislation In March 2017, the Governor of Ohio signed legislation into law that allows utilities to file an application to recover infrastructure development costs associated with economic development projects. The new cost recovery provision allows for projects totaling up to $22 million for East Ohio subject to Ohio Commission approval. DSM Rider East Ohio has approval for a DSM rider through which it recovers expenditures related to its DSM programs. In December 2017, East Ohio filed an application with the Ohio Commission seeking approval of an adjustment to the DSM rider to recover a total of $5 million, which includes an under-recovery of costs during the preceding 12-month period. This application is pending. W EST IRGINIA EGULATION In October 2017, the West Virginia Commission approved Hope’s application for new PREP customer rates, for the year beginning November 1, 2017, that provide for projected revenue of $4 million related to capital investments of $21 million, $27 million and $31 million for 2016, 2017 and 2018, respectively. U TAH AND YOMING EGULATION In October 2017, Questar Gas submitted filings with both the Utah Commission and the Wyoming Commission for an approximately $25 million gas cost increase reflecting forecasted increases in commodity and transportation costs. The Utah Commission and the Wyoming Commission both approved the filings in October 2017 with rates effective November 2017. FERC—G AS Cove Point In November 2016, pursuant to the terms of a previous settlement, Cove Point filed a general rate case for its FERC-jurisdictional services, with 23 proposed rates to be effective January 1, 2017. Cove Point proposed an annual cost-of-service DETI In September 2017, DETI submitted its annual transportation cost rate adjustment to FERC requesting approval to recover $39 million. Also in September 2017, DETI submitted its annual electric power cost adjustment to FERC requesting approval to recover $6 million. In October 2017, FERC approved these adjustments.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	N OTE SSET ETIREMENT BLIGATIONS AROs represent obligations that result from laws, statutes, contracts and regulations related to the eventual retirement of certain of the Companies’ long-lived assets. Dominion Energy’s and Virginia Power’s AROs are primarily associated with the decommissioning of their nuclear generation facilities and ash pond and landfill closures. Dominion Energy Gas’ AROs primarily include plugging and abandonment of gas and oil wells and the interim retirement of natural gas gathering, transmission, distribution and storage pipeline components. The Companies have also identified, but not recognized, AROs related to the retirement of Dominion Energy’s LNG facility, Dominion Energy’s and Dominion Energy Gas’ storage wells in their underground natural gas storage network, certain Virginia Power electric transmission and distribution assets located on property with easements, rights of way, franchises and lease agreements, Virginia Power’s hydroelectric generation facilities and the abatement of certain asbestos not expected to be disturbed in Dominion Energy’s and Virginia Power’s generation facilities. The Companies currently do not have sufficient information to estimate a reasonable range of expected retirement dates for any of these assets since the economic lives of these assets can be extended indefinitely through regular repair and maintenance and they currently have no plans to retire or dispose of any of these assets. As a result, a settlement date is not determinable for these assets and AROs for these assets will not be reflected in the Consolidated Financial Statements until sufficient information becomes available to determine a reasonable estimate of the fair value of the activities to be performed. The Companies continue to monitor operational and strategic developments to identify if sufficient information exists to reasonably estimate a retirement date for these assets. The changes to AROs during 2016 and 2017 were as follows: Amount (millions) Dominion Energy AROs at December 31, 2015 $ 2,103 Obligations incurred during the period (1) 204 Obligations settled during the period (171 ) Revisions in estimated cash flows (2) 245 Accretion 104 AROs at December 31, 2016 (3) $ 2,485 Obligations incurred during the period 37 Obligations settled during the period (214 ) Revisions in estimated cash flows 7 Accretion 117 AROs at December 31, 2017 (3) $ 2,432 Virginia Power AROs at December 31, 2015 $ 1,247 Obligations incurred during the period 9 Obligations settled during the period (115 ) Revisions in estimated cash flows (2) 245 Accretion 57 AROs at December 31, 2016 $ 1,443 Obligations incurred during the period 11 Obligations settled during the period (152 ) Revisions in estimated cash flows (1 ) Accretion 64 AROs at December 31, 2017 $ 1,365 Dominion Energy Gas AROs at December 31, 2015 $ 149 Obligations incurred during the period 6 Obligations settled during the period (8 ) Accretion 9 AROs at December 31, 2016 (4) $ 156 Obligations incurred during the period 2 Obligations settled during the period (7 ) Accretion 9 AROs at December 31, 2017 (4) $ 160 (1) Primarily reflects AROs assumed in the Dominion Energy Questar Combination. See Note 3 for further information. (2) Primarily reflects future ash pond and landfill closure costs at certain utility generation facilities. See Note 22 for further information. (3) Includes $249 million and $263 million reported in other current liabilities at December 31, 2016, and 2017, respectively. (4) Includes $147 million and $146 million reported in other deferred credits and other liabilities, with the remainder recorded in other current liabilities, at December 31, 2016 and 2017, respectively. Dominion Energy and Virginia Power have established trusts dedicated to funding the future decommissioning of their nuclear plants. At December 31, 2017 and 2016, the aggregate fair value of Dominion Energy’s trusts, consisting primarily of equity and debt securities, totaled $5.1 billion and $4.5 billion, respectively. At December 31, 2017 and 2016, the aggregate fair value of Virginia Power’s trusts, consisting primarily of debt and equity securities, totaled $2.4 billion and $2.1 billion, respectively.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	N OTE ARIABLE NTEREST NTITIES The primary beneficiary of a VIE is required to consolidate the VIE and to disclose certain information about its significant variable interests in the VIE. The primary beneficiary of a VIE is the entity that has both 1) the power to direct the activities that most significantly impact the entity’s economic performance and 2) the obligation to absorb losses or receive benefits from the entity that could potentially be significant to the VIE. D OMINION NERGY At December 31, 2017, Dominion Energy owns the general partner, 50.6% of the common and subordinated units and 37.5% of the convertible preferred interests in Dominion Energy Midstream, which owns a preferred equity interest and the general partner interest in Cove Point. Additionally, Dominion Energy owns the manager and 67% of the membership interest in certain merchant solar facilities, as discussed in Note 2. Dominion Energy has concluded that these entities are VIEs due to the limited partners or members lacking the characteristics of a controlling financial interest. In addition, in 2016 Dominion Energy created a wholly owned subsidiary, SBL Holdco, as a holding company of its interest in the VIE merchant solar facilities and accordingly SBL Holdco is a VIE. Dominion Energy is the primary beneficiary of Dominion Energy Midstream, SBL Holdco and the merchant solar facilities, and Dominion Energy Midstream is the primary beneficiary of Cove Point, as they have the power to direct the activities that most significantly impact their economic performance as well as the obligation to absorb losses and benefits which could be significant to them. Dominion Energy’s securities due within one year and long-term debt include $30 million and $332 million, respectively, of debt issued in 2016 by SBL Holdco net of issuance costs that is nonrecourse to Dominion Energy and is secured by SBL Holdco’s interest in the merchant solar facilities. Dominion Energy owns a 48% membership interest in Atlantic Coast Pipeline. See Note 9 for more details regarding the nature of this entity. Dominion Energy concluded that Atlantic Coast Pipeline is a VIE because it has insufficient equity to finance its activities without additional subordinated financial support. Dominion Energy has concluded that it is not the primary beneficiary of Atlantic Coast Pipeline as it does not have the power to direct the activities of Atlantic Coast Pipeline that most significantly impact its economic performance, as the power to direct is shared among multiple unrelated parties. Dominion Energy is obligated to provide capital contributions based on its ownership percentage. Dominion Energy’s maximum exposure to loss is limited to its current and future investment as well as any obligations under a guarantee provided. See Note 22 for more information. D OMINION NERGY AND IRGINIA OWER Dominion Energy’s and Virginia Power’s nuclear decommissioning trust funds and Dominion Energy’s rabbi trusts hold investments in limited partnerships or similar type entities (see Note 9 for further details). Dominion Energy and Virginia Power concluded that these partnership investments are VIEs due to the limited partners lacking the characteristics of a controlling financial interest. Dominion Energy and Virginia Power have concluded neither is the primary beneficiary as they do not have the power to direct the activities that most significantly impact these VIEs’ economic performance. Dominion Energy and Virginia Power are obligated to provide capital contributions to the partnerships as required by each partnership agreement based on their ownership percentages. Dominion Energy and Virginia Power’s maximum exposure to loss is limited to their current and future investments. D OMINION NERGY AND OMINION NERGY AS Dominion Energy previously concluded that Iroquois was a VIE because a non-affiliated V IRGINIA OWER Virginia Power had long-term power and capacity contracts with five non-utility non-utility D OMINION NERGY AS DETI has been engaged to oversee the construction of, and to subsequently operate and maintain, the projects undertaken by Atlantic Coast Pipeline based on the overall direction and oversight of Atlantic Coast Pipeline’s members. An affiliate of DETI holds a membership interest in Atlantic Coast Pipeline, therefore DETI is considered to have a variable interest in Atlantic Coast Pipeline. The members of Atlantic Coast Pipeline hold the power to direct the construction, operations and maintenance activities of the entity. DETI has concluded it is not the primary beneficiary of Atlantic Coast Pipeline as it does not have the power to direct the activities of Atlantic Coast Pipeline that most significantly impact its economic performance. DETI has no obligation to absorb any losses of the VIE. See Note 24 for information about associated related party receivable balances. V IRGINIA OWER AND OMINION NERGY AS Virginia Power and Dominion Energy Gas purchased shared services from DES, an affiliated VIE, of $340 million and $126 million, $346 million and $123 million, and $318 million and $115 million for the years ended December 31, 2017, 2016 and 2015, respectively. Virginia Power and Dominion Energy Gas determined that neither is the primary beneficiary of DES as neither has both the power to direct the activities that most significantly impact its economic performance as well as the obligation to absorb losses and benefits which could be significant to it. DES provides accounting, legal, finance and certain administrative and technical services to all Dominion Energy subsidiaries, including Virginia Power and Dominion Energy Gas. Virginia Power and Dominion Energy Gas have no obligation to absorb more than their allocated shares of DES costs.

Short-Term Debt and Credit Agre

Short-Term Debt and Credit Agreements	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Short-Term Debt and Credit Agreements	N OTE HORT TERM EBT AND REDIT GREEMENTS The Companies use short-term debt to fund working capital requirements and as a bridge to long-term debt financings. The levels of borrowing may vary significantly during the course of the year, depending upon the timing and amount of cash requirements not satisfied by cash from operations. In addition, Dominion Energy utilizes cash and letters of credit to fund collateral requirements. Collateral requirements are impacted by commodity prices, hedging levels, Dominion Energy’s credit ratings and the credit quality of its counterparties. D OMINION NERGY Commercial paper and letters of credit outstanding, as well as capacity available under credit facilities, were as follows: Facility Limit Outstanding Commercial Paper (2) Outstanding Letters of Credit Facility Capacity Available (millions) At December 31, 2017 Joint revolving credit facility (1) $ 5,000 $3,298 $ $ 1,702 Joint revolving credit facility (1) 500 — 76 424 Total $ 5,500 $3,298 $76 $ 2,126 At December 31, 2016 Joint revolving credit facility (1) $ 5,000 $3,155 $ $ 1,845 Joint revolving credit facility (1) 500 — 85 415 Total $ 5,500 $3,155 $85 $ 2,260 (1) These credit facilities mature in April 2020 and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $2.0 billion of letters of credit. (2) The weighted-average interest rates of the outstanding commercial paper supported by Dominion Energy’s credit facilities were 1.61% and 1.05% at December 31, 2017 and 2016, respectively. Questar Gas’ short-term financing is supported through its access as co-borrower sub-limit Dominion Energy has indicated its intention to replace the existing two joint revolving credit facilities with a $6.0 billion joint revolving credit facility in the first quarter of 2018. Terms and covenants of the new credit facility are expected to be similar to the existing credit facilities, including that Virginia Power, Dominion Energy Gas and Questar Gas will remain as co-borrowers, co-borrower, In addition to the credit facilities mentioned above, SBL Holdco has $30 million of credit facilities which have an original stated maturity date of December 2017 with automatic one-year one-year In February 2018, Dominion Energy borrowed $950 million under a 364-Day V IRGINIA OWER Virginia Power’s short-term financing is supported through its access as co-borrower Virginia Power’s share of commercial paper and letters of credit outstanding under its joint credit facilities with Dominion Energy, Dominion Energy Gas and Questar Gas were as follows: Facility Limit (1) Outstanding Commercial Paper (2) Outstanding Letters of Credit (millions) At December 31, 2017 Joint revolving credit facility (1) $5,000 $542 $— Joint revolving credit facility (1) 500 — — Total $5,500 $542 $— At December 31, 2016 Joint revolving credit facility (1) $5,000 $ 65 $— Joint revolving credit facility (1) 500 — 1 Total $5,500 $ 65 $ 1 (1) The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Sub-limits sub-limit sub-limit, sub-limit sub-limit, (2) The weighted-average interest rates of the outstanding commercial paper supported by these credit facilities were 1.65% and 0.97% at December 31, 2017 and 2016, respectively. In addition to the credit facility commitments mentioned above, Virginia Power also has a $100 million credit facility with a maturity date of April 2020. As of December 31, 2017, this facility supports $100 million of certain variable rate tax-exempt tax-exempt D OMINION NERGY AS Dominion Energy Gas’ short-term financing is supported by its access as co-borrower Dominion Energy Gas’ share of commercial paper and letters of credit outstanding under its joint credit facilities with Dominion Energy, Virginia Power and Questar Gas were as follows: Facility Limit (1) Outstanding Commercial Paper (2) Outstanding Letters of Credit (millions) At December 31, 2017 Joint revolving credit facility (1) $1,000 $629 $— Joint revolving credit facility (1) 500 — — Total $1,500 $629 $— At December 31, 2016 Joint revolving credit facility (1) $1,000 $460 $— Joint revolving credit facility (1) 500 — — Total $1,500 $460 $— (1) A maximum of a combined $1.5 billion of the facilities is available to Dominion Energy Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Sub-limits sub-limit sub-limit, sub-limit sub-limit, (2) The weighted-average interest rate of the outstanding commercial paper supported by these credit facilities was 1.57% and 1.00% at December 31, 2017 and 2016, respectively.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	N OTE ONG TERM EBT At December 31, 2017 Weighted- average Coupon (1) 2017 2016 (millions, except percentages) Dominion Energy Gas Holdings, LLC: Unsecured Senior Notes: 2.5% and 2.8%, due 2019 and 2020 2.68 % $ 1,150 $ 1,150 2.875% to 4.8%, due 2023 to 2044 (2) 3.90 % 2,450 2,413 Dominion Energy Gas Holdings, LLC total principal $ 3,600 $ 3,563 Unamortized discount and debt issuance costs (30 ) (35 ) Dominion Energy Gas Holdings, LLC total long-term debt $ 3,570 $ 3,528 Virginia Electric and Power Company: Unsecured Senior Notes: 1.2% to 7.25%, due 2017 to 2022 3.92 % $ 1,950 $ 2,554 2.75% to 8.875%, due 2023 to 2047 4.53 % 8,690 7,190 Tax-Exempt (3) Variable rates, due 2017 to 2027 1.27 % 100 175 1.75% to 5.6%, due 2023 to 2041 2.25 % 678 678 Virginia Electric and Power Company total principal $ 11,418 $ 10,597 Securities due within one year 4.17 % (850 ) (678 ) Unamortized discount, premium and debt issuances costs, net (72 ) (67 ) Virginia Electric and Power Company total long-term debt $ 10,496 $ 9,852 Dominion Energy, Inc.: Unsecured Senior Notes: Variable rates, due 2019 and 2020 1.99 % $ 800 $ — 1.25% to 6.4%, due 2017 to 2022 2.95 % 5,800 5,750 2.85% to 7.0%, due 2024 to 2044 4.72 % 5,049 4,649 Tax-Exempt (4) — 75 Unsecured Junior Subordinated Notes: 2.579% to 4.104%, due 2019 to 2021 3.08 % 2,100 1,100 Payable to Affiliated Trust, 8.4% due 2031 8.40 % 10 10 Enhanced Junior Subordinated Notes: 5.25% and 5.75%, due 2054 and 2076 5.48 % 1,485 1,485 Variable rates, due 2066 4.15 % 422 422 Remarketable Subordinated Notes, 1.5% and 2.0%, due 2020 to 2024 2.00 % 1,400 2,400 Unsecured Debentures and Senior Notes ( 5 ) 6.8% and 6.875%, due 2026 and 2027 6.81 % 89 89 Term Loan, variable rate, due 2017 ( 6 ) — 250 Unsecured Senior and Medium-Term Notes (6) 5.31% to 6.85%, due 2017 and 2018 5.72 % 120 135 2.98% to 7.20%, due 2024 to 2051 4.37 % 600 500 Term Loans, variable rates, due 2023 and 2024 ( 7 ) 3.74 % 638 405 Tax-Exempt ( 8 ) 1.55 % 27 27 Dominion Energy Midstream Partners, LP: Term Loan, variable rate, due 2019 2.74 % 300 300 Unsecured Senior and Medium-Term Notes, 5.83% and 6.48%, due 2018 (9) 5.84 % 255 255 Unsecured Senior Notes, 4.875%, due 2041 ( 9 ) 4.88 % 180 180 Dominion Energy Gas Holdings, LLC total principal (from above) 3,600 3,563 Virginia Electric and Power Company total principal (from above) 11,418 10,597 Dominion Energy, Inc. total principal $ 34,293 $ 32,192 Fair value hedge valuation ( 10 ) (22 ) (1 ) Securities due within one year ( 11) (12 ) 3.44 % (3,078 ) (1,709 ) Unamortized discount, premium and debt issuance costs, net (245 ) (251 ) Dominion Energy, Inc. total long-term debt $ 30,948 $ 30,231 (1) Represents weighted-average coupon rates for debt outstanding as of December 31, 2017. (2) Amount includes foreign currency remeasurement adjustments. (3) These financings relate to certain pollution control equipment at Virginia Power’s generating facilities. As of December 31, 2017, certain variable rate tax-exempt tax-exempt (4) Represents variable rate Massachusetts Development Finance Agency Solid Waste Disposal Revenue Bonds due in 2041 repaid in August 2017. (5) Represents debt assumed by Dominion Energy from the merger of its former CNG subsidiary. (6) Represents debt obligations of Dominion Energy Questar or Questar Gas. See Note 3 for more information. (7) Represents debt associated with SBL Holdco and Dominion Solar Projects III, Inc. The debt is nonrecourse to Dominion Energy and is secured by SBL Holdco’s and Dominion Solar Projects III, Inc.’s interest in certain merchant solar facilities. (8) Represents debt obligations of a DGI subsidiary. (9) Represents debt obligations of Dominion Energy Questar Pipeline. See Note 3 for more information. (10) Represents the valuation of certain fair value hedges associated with Dominion Energy’s fixed rate debt. (11) Excludes $250 million of Dominion Energy Questar Pipeline’s senior notes that matured in February 2018 which were repaid using proceeds from the January 2018 issuance, through private placement, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively. (12) Includes $20 million of estimated mandatory prepayments due within one year based on estimated cash flows in excess of debt service at SBL Holdco and Dominion Solar Projects III, Inc. Based on stated maturity dates rather than early redemption dates that could be elected by instrument holders, the scheduled principal payments of long-term debt at December 31, 2017, were as follows: 2018 2019 2020 2021 2022 Thereafter Total (millions, except percentages) Dominion Energy Gas $ — $ 450 $ 700 $ — $ — $ 2,450 $ 3,600 Weighted-average Coupon 2.50 % 2.80 % 3.90 % Virginia Power Unsecured Senior Notes $ 850 $ 350 $ — $ — $ 750 $ 8,690 $ 10,640 Tax-Exempt — — — — — 778 778 Total $ 850 $ 350 $ — $ — $ 750 $ 9,468 $ 11,418 Weighted-average Coupon 4.17 % 5.00 % 3.15 % 4.33 % Dominion Energy Term Loans (1) $ 36 $ 336 $ 35 $ 35 $ 34 $ 462 $ 938 Unsecured Senior Notes ( 2 ) 3,275 3,400 1,000 900 1,500 17,058 27,133 Tax-Exempt — — — — — 805 805 Unsecured Junior Subordinated Notes Payable to Affiliated Trusts — — — — — 10 10 Unsecured Junior Subordinated Notes — 550 1,000 550 — — 2,100 Enhanced Junior Subordinated Notes — — — — — 1,907 1,907 Remarketable Subordinated Notes — — — 700 — 700 1,400 Total $ 3,311 $ 4,286 $ 2,035 $ 2,185 $ 1,534 $ 20,942 $ 34,293 Weighted-average Coupon 3.62 % 2.89 % 2.58 % 3.12 % 2.97 % 4.38 % (1) Excludes mandatory prepayments associated with SBL Holdco and Dominion Solar Projects III, Inc. based on cash flows in excess of debt service. At December 31, 2017, $20 million of estimated mandatory prepayments due within one year were included in securities due within one year in Dominion Energy’s Consolidated Balance Sheets. (2) In February 2018, $250 million of Dominion Energy Questar Pipeline’s senior notes were repaid using proceeds from the January 2018 issuance, through private placements, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively. As a result, at December 31, 2017, $250 million was included in long-term debt in the Consolidated Balance Sheets. The Companies short-term credit facilities and long-term debt agreements contain customary covenants and default provisions. As of December 31, 2017, there were no events of default under these covenants. Enhanced Junior Subordinated Notes In June 2006 and September 2006, Dominion Energy issued $300 million of June 2006 hybrids and $500 million of September 2006 hybrids, respectively. Beginning June 30, 2016, the June 2006 hybrids bear interest at three-month LIBOR plus 2.825%, reset quarterly. Previously, interest was fixed at 7.5% per year. The September 2006 hybrids bear interest at the three-month LIBOR plus 2.3%, reset quarterly. In October 2014, Dominion Energy issued $685 million of October 2014 hybrids that will bear interest at 5.75% per year until October 1, 2024. Thereafter, they will bear interest at the three-month LIBOR plus 3.057%, reset quarterly. Dominion Energy may defer interest payments on the hybrids on one or more occasions for up to 10 consecutive years. If the interest payments on the hybrids are deferred, Dominion Energy may not make distributions related to its capital stock, including dividends, redemptions, repurchases, liquidation payments or guarantee payments during the deferral period. Also, during the deferral period, Dominion Energy may not make any payments on or redeem or repurchase any debt securities that are equal in right of payment with, or subordinated to, the hybrids. Dominion Energy executed RCCs in connection with its issuance of the June 2006 hybrids and the September 2006 hybrids. Under the terms of the RCCs, Dominion Energy covenants to and for the benefit of designated covered debtholders, as may be designated from time to time, that Dominion Energy shall not redeem, repurchase, or defease all or any part of the hybrids, and shall not cause its majority owned subsidiaries to purchase all or any part of the hybrids, on or before their applicable RCC termination date, unless, subject to certain limitations, during the 180 days prior to such activity, Dominion Energy has received a specified amount of proceeds as set forth in the RCCs from the sale of qualifying securities that have equity-like characteristics that are the same as, or more equity-like than the applicable characteristics of the hybrids at that time, as more fully described in the RCCs. In September 2011, Dominion Energy amended the RCCs of the June 2006 hybrids and September 2006 hybrids to expand the measurement period for consideration of proceeds from the sale of common stock issuances from 180 days to 365 days. The proceeds Dominion Energy receives from the replacement offering, adjusted by a predetermined factor, must equal or exceed the redemption or repurchase price. In 2015, Dominion Energy purchased and cancelled $14 million and $3 million of the June 2006 hybrids and the September 2006 hybrids, respectively. In the first quarter of 2016, Dominion Energy purchased and cancelled $38 million and $4 million of the June 2006 hybrids and the September 2006 hybrids, respectively. In July 2016, Dominion Energy launched a tender offer to purchase up to $200 million in aggregate of additional June 2006 hybrids and September 2006 hybrids, which expired on August 1, 2016. In connection with the tender offer, Dominion Energy purchased and cancelled $125 million and $74 million of the June 2006 hybrids and the September 2006 hybrids, respectively. All purchases were conducted in compliance with the applicable RCC. Also in July 2016, Dominion Energy issued $800 million of 5.25% July 2016 hybrids. The proceeds were used for general corporate purposes, including to finance the tender offer. The July 2016 hybrids are listed on the NYSE under the symbol DRUA. Remarketable Subordinated Notes In June 2013, Dominion Energy issued $550 million of 2013 Series A 6.125% Equity Units and $550 million of 2013 Series B 6.0% Equity Units, initially in the form of Corporate Units. In July 2014, Dominion Energy issued $1.0 billion of 2014 Series A 6.375% Equity Units, initially in the form of Corporate Units. The Corporate Units were listed on the NYSE under the symbols DCUA, DCUB and DCUC respectively. Each Corporate Unit consisted of a stock purchase contract and 1/20 interest in a RSN issued by Dominion Energy. The stock purchase contracts obligated the holders to purchase shares of Dominion Energy common stock at a future settlement date prior to the relevant RSN maturity date. The purchase price paid under the stock purchase contracts was $50 per Corporate Unit and the number of shares purchased was determined under a formula based upon the average closing price of Dominion Energy common stock near the settlement date. The RSNs were pledged as collateral to secure the purchase of common stock under the related stock purchase contracts. In May 2017, Dominion Energy successfully remarketed the $1.0 billion 2014 Series A 1.50% RSNs due 2020 pursuant to the terms of the related 2014 Equity Units. In connection with the remarketing, the interest rate on the junior subordinated notes was reset to 2.579%, payable on a semi-annual basis and Dominion Energy ceased to have the ability to redeem the notes at its option or defer interest payments. In March 2016 and May 2016, Dominion Energy successfully remarketed the $550 million 2013 Series A 1.07% RSNs due 2021 and the $550 million 2013 Series B 1.18% RSNs due 2019, respectively, pursuant to the terms of the related 2013 Equity Units. In connection with the remarketings, the interest rate on the Series A and Series B junior subordinated notes was reset to 4.104% and 2.962%, respectively, payable on a semi-annual basis and Dominion Energy ceased to have the ability to redeem the notes at its option or defer interest payments. At December 31, 2017, the securities are included in junior subordinated notes in Dominion Energy’s Consolidated Balance Sheets. Dominion Energy did not receive any proceeds from the remarketings. Remarketing proceeds belonged to the investors holding the related equity units and were temporarily used to purchase a portfolio of treasury securities. Upon maturity of each portfolio, the proceeds were applied on behalf of investors on the related stock purchase contract settlement date to pay the purchase price to Dominion Energy for issuance of 12.5 million shares of its common stock in July 2017 and 8.5 million shares of its common stock in both April 2016 and July 2016. See Issuance of Common Stock below for a description of common stock issued by Dominion Energy under the stock purchase contracts. In August 2016, Dominion Energy issued $1.4 billion of 2016 Series A 6.75% Equity Units, initially in the form of Corporate Units. The Corporate Units are listed on the NYSE under the symbol DCUD. The net proceeds from the 2016 Equity Units were used to finance the Dominion Energy Questar Combination. See Note 3 for more information. Each 2016 Series A Corporate Unit consists of a stock purchase contract, a 1/40 interest in a 2016 Series A-1 A-2 Dominion Energy makes quarterly interest payments on the RSNs and quarterly contract adjustment payments on the stock purchase contracts, at the rates described below. Dominion Energy may defer payments on the stock purchase contracts and the RSNs for one or more consecutive periods but generally not beyond the purchase contract settlement date. If payments are deferred, Dominion Energy may not make any cash distributions related to its capital stock, including dividends, redemptions, repurchases, liquidation payments or guarantee payments. Also, during the deferral period, Dominion Energy may not make any payments on or redeem or repurchase any debt securities that are equal in right of payment with, or subordinated to, the RSNs. Dominion Energy has recorded the present value of the stock purchase contract payments as a liability offset by a charge to equity. Interest payments on the RSNs are recorded as interest expense and stock purchase contract payments are charged against the liability. Accretion of the stock purchase contract liability is recorded as imputed interest expense. In calculating diluted EPS, Dominion Energy applies the treasury stock method to the equity units. Pursuant to the terms of the 2016 Equity Units, Dominion Energy expects to remarket both the 2016 Series A-1 A-2 Under the terms of the stock purchase contracts, assuming no anti-dilution or other adjustments, Dominion Energy will issue between 15.0 million and 18.8 million shares in August 2019. A total of 23.1 million shares of Dominion Energy’s common stock has been reserved for issuance in connection with the stock purchase contracts. Selected information about Dominion Energy’s equity units is presented below: Issuance Date Units Issued Total Net Proceeds Total Long-term Debt RSN Annual Interest Rate Stock Purchase Contract Annual Rate Stock Purchase Contract Liability (1) Stock Purchase Settlement Date (millions, except interest rates) 8/15/2016 (2) 28 $ 1,374.8 $1,400.0 2.000 % (3) 4.750 % $190.6 8/15/2019 (1) Payments of $101 million and $94 million were made in 2017 and 2016, respectively, including payments for the remarketed 2013 Series A and B notes and the remarketed 2014 Series A notes. The stock purchase contract liability was $111 million and $212 million at December 31, 2017 and 2016, respectively. (2) The maturity dates of the $700 million Series A-1 A-2 (3) Annual interest rate applies to each of the Series A-1 A-2

PREFERRED STOCK

PREFERRED STOCK	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
PREFERRED STOCK	N OTE REFERRED TOCK Dominion Energy is authorized to issue up to 20 million shares of preferred stock; however, none were issued and outstanding at December 31, 2017 or 2016. Virginia Power is authorized to issue up to 10 million shares of preferred stock, $100 liquidation preference; however, none were issued and outstanding at December 31, 2017 or 2016.

EQUITY

EQUITY	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
EQUITY	N OTE QUITY Issuance of Common Stock D OMINION NERGY Dominion Energy maintains Dominion Energy Direct ® During 2017, Dominion Energy received cash proceeds, net of fees and commissions, of $1.3 billion from the issuance of approximately 17 million shares of common stock through various programs resulting in approximately 645 million shares of common stock outstanding at December 31, 2017. These proceeds include cash of $302 million received from the issuance of 3.8 million of such shares through Dominion Energy Direct ® In July 2017, Dominion Energy issued 12.5 million shares under the related stock purchase contracts entered into as part of Dominion Energy’s 2014 Equity Units and received proceeds of $1.0 billion. In both April 2016 and July 2016, Dominion Energy issued 8.5 million shares under the related stock purchase contracts entered into as part of Dominion Energy’s 2013 Equity Units and received $1.1 billion of total proceeds. Additionally, Dominion Energy completed a market issuance of equity in April 2016 of 10.2 million shares and received proceeds of $756 million through a registered underwritten public offering. A portion of the net proceeds was used to finance the Dominion Energy Questar Combination. See Note 3 for more information. In June 2017, Dominion Energy filed an SEC shelf registration for the sale of debt and equity securities including the ability to sell common stock through an at-the-market at-the-market V IRGINIA OWER In 2017, 2016 and 2015, Virginia Power did not issue any shares of its common stock to Dominion Energy. Shares Reserved for Issuance At December 31, 2017, Dominion Energy had approximately 67 million shares reserved and available for issuance for Dominion Energy Direct ® Repurchase of Common Stock Dominion Energy did not repurchase any shares in 2017 or 2016 and does not plan to repurchase shares during 2018, except for shares tendered by employees to satisfy tax withholding obligations on vested restricted stock, which do not count against its stock repurchase authorization. Purchase of Dominion Energy Midstream Units In September 2015, Dominion Energy initiated a program to purchase from the market up to $50 million of common units representing limited partner interests in Dominion Energy Midstream, which expired in September 2016. Dominion Energy purchased approximately 658,000 common units for $17 million and 887,000 common units for $25 million for the years ended December 31, 2016 and 2015, respectively. Issuance of Dominion Energy Midstream Units In 2017, Dominion Energy Midstream received $18 million of proceeds from the issuance of common units through its at-the-market In 2016, Dominion Energy Midstream received $482 million of proceeds from the issuance of common units and $490 million of proceeds from the issuance of convertible preferred units. The net proceeds were primarily used to finance a portion of the acquisition of Dominion Energy Questar Pipeline from Dominion Energy. See Note 3 for more information. The holders of the convertible preferred units are entitled to receive cumulative quarterly distributions payable in cash or additional convertible preferred units, subject to certain conditions. The units are convertible into Dominion Energy Midstream common units on a one-for-one Accumulated Other Comprehensive Income (Loss) Presented in the table below is a summary of AOCI by component: At December 31, 2017 2016 (millions) Dominion Energy Net deferred losses on derivatives-hedging activities, net of tax of $188 and $173 $ (301 ) $ (280 ) Net unrealized gains on nuclear decommissioning trust funds, net of tax of $(419) and $(318) 747 569 Net unrecognized pension and other postretirement benefit costs, net of tax of $692 and $691 (1,101 ) (1,082 ) Other comprehensive loss from equity method investees, net of tax of $2 and $4 (3 ) (6 ) Total AOCI, including noncontrolling interest $ (658 ) $ (799 ) Less other comprehensive income attributable to noncontrolling interest 1 — Total AOCI, excluding noncontrolling interest $ (659 ) $ (799 ) Virginia Power Net deferred losses on derivatives-hedging activities, net of tax of $8 and $5 $ (12 ) $ (8 ) Net unrealized gains on nuclear decommissioning trust funds, net of tax of $(47) and $(35) 74 54 Total AOCI $ 62 $ 46 Dominion Energy Gas Net deferred losses on derivatives-hedging activities, net of tax of $15 and $15 $ (23 ) $ (24 ) Net unrecognized pension costs, net of tax of $59 and $68 (75 ) (99 ) Total AOCI $ (98 ) $ (123 ) D OMINION NERGY The following table presents Dominion Energy’s changes in AOCI by component, net of tax: Deferred gains and losses on derivatives- hedging activities Unrealized gains and losses on investment securities Unrecognized pension and other postretirement benefit costs Other comprehensive loss from equity method investees Total (millions) Year Ended December 31, 2017 Beginning balance $(280 ) $569 $(1,082 ) $(6 ) $(799 ) Other comprehensive income before reclassifications: gains (losses) 8 215 (69 ) 3 157 Amounts reclassified from AOCI: (gains) losses (1) (29 ) (37) 50 — (16 ) Net current period other comprehensive income (loss) (21 ) 178 (19 ) 3 141 Less other comprehensive income attributable to noncontrolling interest 1 — — — 1 Ending balance $(302 ) $747 $(1,101 ) $(3 ) $(659 ) Year Ended December 31, 2016 Beginning balance $(176 ) $504 $ (797 ) $(5 ) $(474 ) Other comprehensive income before reclassifications: gains (losses) 55 93 (319 ) (1 ) (172 ) Amounts reclassified from AOCI: (gains) losses (1) (159 ) (28) 34 — (153 ) Net current period other comprehensive income (loss) (104 ) 65 (285 ) (1 ) (325 ) Ending balance $(280 ) $569 $(1,082 ) $(6 ) $(799 ) (1) See table below for details about these reclassifications. The following table presents Dominion Energy’s reclassifications out of AOCI by component: Details about AOCI components Amounts reclassified from AOCI Affected line item in the Consolidated Statements of Income (millions) Year Ended December 31, 2017 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $ (81 ) Operating revenue 2 Purchased gas Interest rate contracts 52 Interest and related charges Foreign currency contracts (20 ) Other Income Total (47 ) Tax 18 Income tax expense Total, net of tax $ (29 ) Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $ (81 ) Other income Impairment 23 Other income Total (58 ) Tax 21 Income tax expense Total, net of tax $ (37 ) Unrecognized pension and other postretirement benefit costs: Amortization of prior-service costs (credits) $ (21 ) Other income Amortization of actuarial losses 103 Other income Total 82 Tax (32 ) Income tax expense Total, net of tax $ 50 Year Ended December 31, 2016 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $(330 ) Operating revenue 13 Purchased gas 10 Electric fuel and other Interest rate contracts 31 Interest and related charges Foreign currency contracts 17 Other Income Total (259 ) Tax 100 Income tax expense Total, net of tax $(159 ) Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $ (66 ) Other income Impairment 23 Other income Total (43 ) Tax 15 Income tax expense Total, net of tax $ (28 ) Unrecognized pension and other postretirement benefit costs: Prior-service costs (credits) $ (15 ) Other income Actuarial losses 71 Other income Total 56 Tax (22 ) Income tax expense Total, net of tax $ 34 V IRGINIA OWER The following table presents Virginia Power’s changes in AOCI by component, net of tax: Deferred gains and losses on derivatives- hedging activities Unrealized gains and losses on investment securities Total (millions) Year Ended December 31, 2017 Beginning balance $ (8 ) $54 $46 Other comprehensive income before reclassifications: gains (losses) (5 ) 24 19 Amounts reclassified from AOCI: (gains) losses (1) 1 (4 ) (3 ) Net current period other comprehensive income (loss) (4 ) 20 16 Ending balance $(12) $74 $62 Year Ended December 31, 2016 Beginning balance $ (7 ) $47 $40 Other comprehensive income before reclassifications: gains (losses) (2 ) 11 9 Amounts reclassified from AOCI: (gains) losses (1) 1 (4 ) (3 ) Net current period other comprehensive income (loss) (1 ) 7 6 Ending balance $ (8 ) $54 $46 (1) See table below for details about these reclassifications. The following table presents Virginia Power’s reclassifications out of AOCI by component: Details about AOCI components Amounts reclassified from AOCI Affected line item in the Consolidated Statements of Income (millions) Year Ended December 31, 2017 (Gains) losses on cash flow hedges: Interest rate contracts $ 1 Interest and related charges Total 1 Tax — Income tax expense Total, net of tax $ 1 Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $(9 ) Other income Impairment 2 Other income Total (7 ) Tax 3 Income tax expense Total, net of tax $(4 ) Year Ended December 31, 2016 (Gains) losses on cash flow hedges: Interest rate contracts $ 1 Interest and related charges Total 1 Tax — Income tax expense Total, net of tax $ 1 Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $(9 ) Other income Impairment 3 Other income Total (6 ) Tax 2 Income tax expense Total, net of tax $(4 ) D OMINION NERGY AS The following table presents Dominion Energy Gas’ changes in AOCI by component, net of tax: Deferred gains and losses on derivatives- hedging activities Unrecognized pension costs Total (millions) Year Ended December 31, 2017 Beginning balance $(24 ) $(99 ) $(123 ) Other comprehensive income before reclassifications: gains (losses) 5 20 25 Amounts reclassified from AOCI (1) (4 ) 4 — Net current period other comprehensive income (loss) 1 24 25 Ending balance $(23 ) $(75 ) $ (98 ) Year Ended December 31, 2016 Beginning balance $(17 ) $(82 ) $ (99 ) Other comprehensive income before reclassifications: gains (losses) (16 ) (20 ) (36 ) Amounts reclassified from AOCI (1) 9 3 12 Net current period other comprehensive income (loss) (7 ) (17 ) (24 ) Ending balance $(24 ) $(99 ) $(123 ) (1) See table below for details about these reclassifications. The following table presents Dominion Energy Gas’ reclassifications out of AOCI by component: Details about AOCI components Amounts from AOCI Affected line item in the Consolidated Statements of Income (millions) Year Ended December 31, 2017 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $ 8 Operating revenue Interest rate contracts 5 Interest and related charges Foreign currency contracts (20 ) Other income Total (7) Tax 3 Income tax expense Total, net of tax $ (4 ) Unrecognized pension costs: Actuarial losses $ 6 Other income Total 6 Tax (2 ) Income tax expense Total, net of tax $ 4 Year Ended December 31, 2016 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $ (4 ) Operating revenue Interest rate contracts 2 Interest and related charges Foreign currency contracts 17 Other income Total 15 Tax (6 ) Income tax expense Total, net of tax $ 9 Unrecognized pension costs: Actuarial losses $ 5 Other income Total 5 Tax (2 ) Income tax expense Total, net of tax $ 3 Stock-Based Awards The 2005 and 2014 Incentive Compensation Plans permit stock-based awards that include restricted stock, performance grants, goal-based stock, stock options, and stock appreciation rights. The Non-Employee non-employee Goal-based stock awards are granted in lieu of cash-based performance grants to certain officers who have not achieved a certain targeted level of share ownership. As of December 31, 2017, unrecognized compensation cost related to nonvested goal-based stock awards was immaterial. Dominion Energy measures and recognizes compensation expense relating to share-based payment transactions over the vesting period based on the fair value of the equity or liability instruments issued. Dominion Energy’s results for the years ended December 31, 2017, 2016 and 2015 include $45 million, $33 million, and $39 million, respectively, of compensation costs and $16 million, $11 million, and $14 million, respectively of income tax benefits related to Dominion Energy’s stock-based compensation arrangements. Stock-based compensation cost is reported in other operations and maintenance expense in Dominion Energy’s Consolidated Statements of Income. Excess Tax Benefits are classified as a financing cash flow. R ESTRICTED TOCK Restricted stock grants are made to officers under Dominion Energy’s LTIP and may also be granted to certain key non-officer Shares Weighted - average Grant Date Fair Value (thousands) Nonvested at December 31, 2014 1,065 $56.74 Granted 302 73.26 Vested (510 ) 50.71 Cancelled and forfeited (2 ) 62.62 Nonvested at December 31, 2015 855 $66.16 Granted 372 71.67 Vested (301 ) 56.83 Cancelled and forfeited (40 ) 71.75 Nonvested at December 31, 2016 886 $71.40 Granted 454 74.24 Vested (287 ) 68.90 Cancelled and forfeited (10 ) 72.37 Nonvested at December 31, 2017 1,043 $73.32 As of December 31, 2017, unrecognized compensation cost related to nonvested restricted stock awards totaled $42 million and is expected to be recognized over a weighted-average period of 2.0 years. The fair value of restricted stock awards that vested was $21 million, $21 million, and $37 million in 2017, 2016 and 2015, respectively. Employees may elect to have shares of restricted stock withheld upon vesting to satisfy tax withholding obligations. The number of shares withheld will vary for each employee depending on the vesting date fair market value of Dominion Energy stock and the applicable federal, state and local tax withholding rates. C ASH ASED ERFORMANCE RANTS Cash-based performance grants are made to Dominion Energy’s officers under Dominion Energy’s LTIP. The actual payout of cash-based performance grants will vary between zero and 200% of the targeted amount based on the level of performance metrics achieved. In February 2015, a cash-based performance grant was made to officers. Payout of the performance grant occurred in January 2017 based on the achievement of two performance metrics during 2015 and 2016: TSR relative to that of companies listed as members of the Philadelphia Utility Index as of the end of the performance period and ROIC. The total of the payout under the grant was $10 million. In February 2016, a cash-based performance grant was made to officers. Payout of the performance grant occurred in January 2018 based on the achievement of two performance metrics during 2016 and 2017: TSR relative to that of companies listed as members of the Philadelphia Utility Index as of the end of the performance period and ROIC. The total of the payout under the grant was $12 million. In February 2017, two cash-based performance grants were made to officers as the Company transitioned from a two-year two-year two-year

Dividend Restrictions

Dividend Restrictions	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Dividend Restrictions	N OTE IVIDEND ESTRICTIONS The Virginia Commission may prohibit any public service company, including Virginia Power, from declaring or paying a dividend to an affiliate if found to be detrimental to the public interest. At December 31, 2017, the Virginia Commission had not restricted the payment of dividends by Virginia Power. The Ohio Commission may prohibit any public service company, including East Ohio, from declaring or paying a dividend to an affiliate if found to be detrimental to the public interest. At December 31, 2017, the Ohio Commission had not restricted the payment of dividends by East Ohio. The Utah Commission may prohibit any public service company, including Questar Gas, from declaring or paying a dividend to an affiliate if found to be detrimental to the public interest. At December 31, 2017, the Utah Commission had not restricted the payment of dividends by Questar Gas. Certain agreements associated with the Companies’ credit facilities contain restrictions on the ratio of debt to total capitalization. These limitations did not restrict the Companies’ ability to pay dividends or receive dividends from their subsidiaries at December 31, 2017. As part of the SCANA Merger Agreement, Dominion Energy shall not declare, set aside or pay any dividends on, or make any other distributions (whether in cash, stock or property) in respect of, any of its capital stock, other than regular quarterly cash dividends. See Note 17 for a description of potential restrictions on dividend payments by Dominion Energy in connection with the deferral of interest payments on certain junior subordinated notes and equity units, initially in the form of corporate units.

EMPLOYEE BENEFITPLANS

EMPLOYEE BENEFITPLANS	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
EMPLOYEE BENEFITPLANS	N OTE MPLOYEE ENEFIT LANS Dominion Energy and Dominion Energy Gas—Defined Benefit Plans Dominion Energy provides certain retirement benefits to eligible active employees, retirees and qualifying dependents. Dominion Energy Gas participates in a number of the Dominion Energy-sponsored retirement plans. Under the terms of its benefit plans, Dominion Energy reserves the right to change, modify or terminate the plans. From time to time in the past, benefits have changed, and some of these changes have reduced benefits. Dominion Energy maintains qualified noncontributory defined benefit pension plans covering virtually all employees. Retirement benefits are based primarily on years of service, age and the employee’s compensation. Dominion Energy’s funding policy is to contribute annually an amount that is in accordance with the provisions of ERISA. The pension programs also provide benefits to certain retired executives under company-sponsored nonqualified employee benefit plans. The nonqualified plans are funded through contributions to grantor trusts. Dominion Energy also provides retiree healthcare and life insurance benefits with annual employee premiums based on several factors such as age, retirement date and years of service. Pension benefits for Dominion Energy Gas employees not represented by collective bargaining units are covered by the Dominion Energy Pension Plan, a defined benefit pension plan sponsored by Dominion Energy that provides benefits to multiple Dominion Energy subsidiaries. Pension benefits for Dominion Energy Gas employees represented by collective bargaining units are covered by separate pension plans for East Ohio and, for DETI, a plan that provides benefits to employees of both DETI and Hope. Employee compensation is the basis for allocating pension costs and obligations between DETI and Hope and determining East Ohio’s share of total pension costs. Retiree healthcare and life insurance benefits for Dominion Energy Gas employees not represented by collective bargaining units are covered by the Dominion Retiree Health and Welfare Plan, a plan sponsored by Dominion Energy that provides certain retiree healthcare and life insurance benefits to multiple Dominion Energy subsidiaries. Retiree healthcare and life insurance benefits for Dominion Energy Gas employees represented by collective bargaining units are covered by separate other postretirement benefit plans for East Ohio and, for DETI, a plan that provides benefits to both DETI and Hope. Employee headcount is the basis for allocating other postretirement benefit costs and obligations between DETI and Hope and determining East Ohio’s share of total other postretirement benefit costs. Pension and other postretirement benefit costs are affected by employee demographics (including age, compensation levels and years of service), the level of contributions made to the plans and earnings on plan assets. These costs may also be affected by changes in key assumptions, including expected long-term rates of return on plan assets, discount rates, healthcare cost trend rates, mortality rates and the rate of compensation increases. Dominion Energy uses December 31 as the measurement date for all of its employee benefit plans, including those in which Dominion Energy Gas participates. Dominion Energy uses the market-related value of pension plan assets to determine the expected return on plan assets, a component of net periodic pension cost, for all pension plans, including those in which Dominion Energy Gas participates. The market-related value recognizes changes in fair value on a straight-line basis over a four-year period, which reduces year-to-year Dominion Energy’s pension and other postretirement benefit plans hold investments in trusts to fund employee benefit payments. Dominion Energy’s pension and other postretirement plan assets experienced aggregate actual returns of $1.6 billion and $534 million in 2017 and 2016, respectively, versus expected returns of $767 million and $691 million, respectively. Dominion Energy Gas’ pension and other postretirement plan assets for employees represented by collective bargaining units experienced aggregate actual returns of $335 million and $130 million in 2017 and 2016, respectively, versus expected returns of $165 million and $157 million, respectively. Differences between actual and expected returns on plan assets are accumulated and amortized during future periods. As such, any investment-related declines in these trusts will result in future increases in the net periodic cost recognized for such employee benefit plans and will be included in the determination of the amount of cash to be contributed to the employee benefit plans. In October 2014, the Society of Actuaries published new mortality tables and mortality improvement scales. Such tables and scales are used to develop mortality assumptions for use in determining pension and other postretirement benefit liabilities and expense. Following evaluation of the new tables, Dominion Energy changed its assumption for mortality rates to reflect a generational improvement scale. This change in assumption increased net periodic benefit cost for Dominion Energy and Dominion Energy Gas (for employees represented by collective bargaining units) by $25 million and $3 million, respectively, for 2015. During 2016, Dominion Energy and Dominion Energy Gas (for employees represented by collective bargaining units) engaged their actuary to conduct an experience study of their employees demographics over a five-year period as compared to significant assumptions that were being used to determine pension and other postretirement benefit obligations and periodic costs. These assumptions primarily included mortality, retirement rates, termination rates, and salary increase rates. The changes in assumptions implemented as a result of the experience study resulted in increases of $290 million and $38 million in the pension and other postretirement benefits obligations, respectively, at December 31, 2016 for Dominion Energy and $24 million and $9 million in the pension and other postretirement benefits obligations, respectively, at December 31, 2016 for Dominion Energy Gas. In addition, these changes increased net periodic benefit costs $42 million for Dominion Energy during 2017. The increase in net periodic benefit costs for Dominion Energy Gas during 2017 was immaterial. P LAN MENDMENTS AND EMEASUREMENTS In the fourth quarter of 2017, Dominion Energy remeasured its pension and other postretirement benefit plans as a result of voluntary and involuntary separation programs at Dominion Energy Questar. The settlement and related remeasurement resulted in a reduction in the pension benefit obligation of approximately $75 million and an increase in the accumulated postretirement benefit obligation of approximately $2 million. The discount rates used for the 2017 pension cost and related settlement were 4.46% as of December 31, 2016, 4.51% as of January 31, 2017 and 4.05% as of June 30 and September 30, 2017. All other assumptions used were consistent with the measurement as of December 31, 2016. In the first quarter of 2017, Dominion Energy and Dominion Energy Gas remeasured an other postretirement benefit plan as a result of an amendment that changed post-65 Also during the first quarter of 2017, Dominion Energy recorded a $7 million ($4 million after-tax) after-tax) In the third quarter of 2016, Dominion Energy remeasured an other postretirement benefit plan as a result of an amendment that changed post-65 F UNDED TATUS The following table summarizes the changes in pension plan and other postretirement benefit plan obligations and plan assets and includes a statement of the plans’ funded status for Dominion Energy and Dominion Energy Gas (for employees represented by collective bargaining units): Pension Benefits Other Postretirement Benefits Year Ended December 31, 2017 2016 2017 2016 (millions, except percentages) Dominion Energy Changes in benefit obligation: Benefit obligation at beginning of year $ 8,132 $ 6,391 $ 1,478 $ 1,430 Dominion Energy Questar Combination — 817 — 85 Service cost 138 118 26 31 Interest cost 345 317 60 65 Benefits paid (323 ) (286 ) (83 ) (83 ) Actuarial (gains) losses during the year 830 784 119 166 Plan amendments (1) 5 — (73 ) (216 ) Settlements and curtailments (2) (75 ) (9 ) 2 — Benefit obligation at end of year $ 9,052 $ 8,132 $ 1,529 $ 1,478 Changes in fair value of plan assets: Fair value of plan assets at beginning of year $ 7,016 $ 6,166 $ 1,512 $ 1,382 Dominion Energy Questar Combination — 704 — 45 Actual return (loss) on plan assets 1,327 426 236 108 Employer contributions 118 15 13 12 Benefits paid (323 ) (286 ) (32 ) (35 ) Settlements (2) (76 ) (9 ) — — Fair value of plan assets at end of year $ 8,062 $ 7,016 $ 1,729 $ 1,512 Funded status at end of year $ (990 ) $ (1,116 ) $ 200 $ 34 Amounts recognized in the Consolidated Balance Sheets at December 31: Noncurrent pension and other postretirement benefit assets $ 1,117 $ 930 $ 261 $ 148 Other current liabilities (8 ) (43 ) — (5 ) Noncurrent pension and other postretirement benefit liabilities (2,099 ) (2,003 ) (61 ) (109 ) Net amount recognized $ (990 ) $ (1,116 ) $ 200 $ 34 Significant assumptions used to determine benefit obligations as of December 31: Discount rate 3.80%–3.81 % 3.31%–4.50 % 3.76% 3.92%–4.47 % Weighted average rate of increase for compensation 4.09 % 4.09 % 3.95%-4.11% 3.29 % Dominion Energy Gas Changes in benefit obligation: Benefit obligation at beginning of year $ 683 $ 608 $ 320 $ 292 Service cost 15 13 4 5 Interest cost 30 30 12 14 Benefits paid (33 ) (32 ) (19 ) (19 ) Actuarial (gains) losses during the year 78 64 34 28 Plan amendments (1) — — (61 ) — Benefit obligation at end of year $ 773 $ 683 $ 290 $ 320 Changes in fair value of plan assets: Fair value of plan assets at beginning of year $ 1,542 $ 1,467 $ 299 $ 283 Actual return (loss) on plan assets 294 107 41 23 Employer contributions — — 12 12 Benefits paid (33 ) (32 ) (19 ) (19 ) Fair value of plan assets at end of year $ 1,803 $ 1,542 $ 333 $ 299 Funded status at end of year $ 1,030 $ 859 $ 43 $ (21 ) Amounts recognized in the Consolidated Balance Sheets at December 31: Noncurrent pension and other postretirement benefit assets $ 1,030 $ 859 $ 57 $ — Noncurrent pension and other postretirement benefit liabilities (3) — — (14 ) (21 ) Net amount recognized $ 1,030 $ 859 $ 43 $ (21 ) Significant assumptions used to determine benefit obligations as of December 31: Discount rate 3.81 % 4.50 % 3.76 % 4.47 % Weighted average rate of increase for compensation 4.11 % 4.11 % n/a n/a (1) 2017 amounts relate primarily to a plan amendment that changed post-65 post-65 (2) 2017 amount relates primarily to settlement and curtailment as a result of the voluntary and involuntary separation programs at Dominion Energy Questar. 2016 amount relates primarily to a settlement for certain executives. (3) Reflected in other deferred credits and other liabilities in Dominion Energy Gas’ Consolidated Balance Sheets. The ABO for all of Dominion Energy’s defined benefit pension plans was $8.2 billion and $7.3 billion at December 31, 2017 and 2016, respectively. The ABO for the defined benefit pension plans covering Dominion Energy Gas employees represented by collective bargaining units was $724 million and $640 million at December 31, 2017 and 2016, respectively. Under its funding policies, Dominion Energy evaluates plan funding requirements annually, usually in the fourth quarter after receiving updated plan information from its actuary. Based on the funded status of each plan and other factors, Dominion Energy determines the amount of contributions for the current year, if any, at that time. During 2017, Dominion Energy and Dominion Energy Gas made no contributions to the qualified defined benefit pension plans other than a $75 million contribution to Dominion Energy’s qualified pension plan to satisfy a regulatory condition to closing of the Dominion Energy Questar Combination and no contributions are currently expected in 2018. In July 2012, the MAP 21 Act was signed into law. This Act includes an increase in the interest rates used to determine plan sponsors’ pension contributions for required funding purposes. In 2014, the HATFA of 2014 was signed into law. Similar to the MAP 21 Act, the HATFA of 2014 adjusts the rules for calculating interest rates used in determining funding obligations. It is estimated that the new interest rates will reduce required pension contributions through 2019. Dominion Energy believes that required pension contributions will rise subsequent to 2019, resulting in an estimated $200 million reduction in net cumulative required contributions over a 10-year Certain regulatory authorities have held that amounts recovered in utility customers’ rates for other postretirement benefits, in excess of benefits actually paid during the year, must be deposited in trust funds dedicated for the sole purpose of paying such benefits. Accordingly, certain of Dominion Energy’s subsidiaries, including Dominion Energy Gas, fund other postretirement benefit costs through VEBAs. Dominion Energy’s remaining subsidiaries do not prefund other postretirement benefit costs but instead pay claims as presented. Dominion Energy’s contributions to VEBAs, all of which pertained to Dominion Energy Gas employees, totaled $12 million for both 2017 and 2016, and Dominion Energy expects to contribute approximately $12 million to the Dominion Energy VEBAs in 2018, all of which pertains to Dominion Energy Gas employees. Dominion Energy and Dominion Energy Gas do not expect any pension or other postretirement plan assets to be returned during 2018. The following table provides information on the benefit obligations and fair value of plan assets for plans with a benefit obligation in excess of plan assets for Dominion Energy and Dominion Energy Gas (for employees represented by collective bargaining units): Pension Benefits Other Postretirement Benefits As of December 31, 2017 2016 2017 2016 (millions) Dominion Energy Benefit obligation $ 8,209 $ 7,386 $191 $470 Fair value of plan assets 6,103 5,340 156 356 Dominion Energy Gas Benefit obligation $ — $ — $157 $320 Fair value of plan assets — — 143 299 The following table provides information on the ABO and fair value of plan assets for Dominion Energy’s pension plans with an ABO in excess of plan assets: As of December 31, 2017 2016 (millions) Accumulated benefit obligation $ 7,392 $ 5,987 Fair value of plan assets 6,103 4,653 The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans: Estimated Future Benefit Payments Pension Benefits Other Postretirement Benefits (millions) Dominion Energy 2018 $373 $ 99 2019 378 101 2020 402 102 2021 418 102 2022 434 102 2023-2027 2,437 486 Dominion Energy Gas 2018 $ 35 $ 19 2019 37 19 2020 38 20 2021 39 20 2022 41 20 2023-2027 214 94 P LAN SSETS Dominion Energy’s overall objective for investing its pension and other postretirement plan assets is to achieve appropriate long-term rates of return commensurate with prudent levels of risk. As a participating employer in various pension plans sponsored by Dominion Energy, Dominion Energy Gas is subject to Dominion Energy’s investment policies for such plans. To minimize risk, funds are broadly diversified among asset classes, investment strategies and investment advisors. The strategic target asset allocations for Dominion Energy’s pension funds are 28% U.S. equity, 18% non-U.S. large-cap, mid-cap small-cap Non-U.S. large-cap small-cap non-U.S. Dominion Energy also utilizes common/collective trust funds as an investment vehicle for its defined benefit plans. A common/collective trust fund is a pooled fund operated by a bank or trust company for investment of the assets of various organizations and individuals in a well-diversified portfolio. Common/collective trust funds are funds of grouped assets that follow various investment strategies. Strategic investment policies are established for Dominion Energy’s prefunded benefit plans based upon periodic asset/liability studies. Factors considered in setting the investment policy include employee demographics, liability growth rates, future discount rates, the funded status of the plans and the expected long-term rate of return on plan assets. Deviations from the plans’ strategic allocation are a function of Dominion Energy’s assessments regarding short-term risk and reward opportunities in the capital markets and/or short-term market movements which result in the plans’ actual asset allocations varying from the strategic target asset allocations. Through periodic rebalancing, actual allocations are brought back in line with the target. Future asset/liability studies will focus on strategies to further reduce pension and other postretirement plan risk, while still achieving attractive levels of returns. Financial derivatives may be used to obtain or manage market exposures and to hedge assets and liabilities. For fair value measurement policies and procedures related to pension and other postretirement benefit plan assets, see Note 6. The fair values of Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) pension plan assets by asset category are as follows: At December 31, 2017 2016 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (millions) Dominion Energy Cash and cash equivalents $ 18 $ — $— $ 18 $ 12 $ 2 $— $ 14 Common and preferred stocks: U.S. 1,902 — — 1,902 1,705 — — 1,705 International 1,151 — — 1,151 928 — — 928 Insurance contracts — 352 — 352 — 334 — 334 Corporate debt instruments 41 729 — 770 35 682 — 717 Government securities 9 676 — 685 13 522 — 535 Total recorded at fair value $ 3,121 $ 1,757 $— $ 4,878 $ 2,693 $ 1,540 $— $ 4,233 Assets recorded at NAV (1) Common/collective trust funds 2,272 1,960 Alternative investments: Real estate funds 111 121 Private equity funds 606 506 Debt funds 161 153 Hedge funds 19 25 Total recorded at NAV $ 3,169 $ 2,765 Total investments (2) $ 8,047 $ 6,998 Dominion Energy Gas Cash and cash equivalents $ 4 $ — $— $ 4 $ 3 $ — $— $ 3 Common and preferred stocks: U.S. 425 — — 425 375 — — 375 International 257 — — 257 203 — — 203 Insurance contracts — 79 — 79 — 73 — 73 Corporate debt instruments 9 163 — 172 8 150 — 158 Government securities 2 151 — 153 3 115 — 118 Total recorded at fair value $ 697 $ 393 $— $ 1,090 $ 592 $ 338 $— $ 930 Assets recorded at NAV (1) Common/collective trust funds 509 430 Alternative investments: Real estate funds 25 27 Private equity funds 135 111 Debt funds 36 34 Hedge funds 4 6 Total recorded at NAV $ 709 $ 608 Total investments (3) $ 1,799 $ 1,538 (1) These investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy. (2) Excludes net assets related to pending sales of securities of $11 million, net accrued income of $19 million, and includes net assets related to pending purchases of securities of $15 million at December 31, 2017. Excludes net assets related to pending sales of securities of $46 million, net accrued income of $19 million, and includes net assets related to pending purchases of securities of $47 million at December 31, 2016. (3) Excludes net assets related to pending sales of securities of $3 million, net accrued income of $4 million, and includes net assets related to pending purchases of securities of $3 million at December 31, 2017. Excludes net assets related to pending sales of securities of $10 million, net accrued income of $4 million, and includes net assets related to pending purchases of securities of $10 million at December 31, 2016. The fair values of Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) other postretirement plan assets by asset category are as follows: At December 31, 2017 2016 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (millions) Dominion Energy Cash and cash equivalents $ 1 $ 2 $— $ 3 $ 1 $ 1 $— $ 2 Common and preferred stocks: U.S. 636 — — 636 571 — — 571 International 196 — — 196 143 — — 143 Insurance contracts — 21 — 21 — 19 — 19 Corporate debt instruments 2 44 — 46 2 40 — 42 Government securities 1 41 — 42 1 30 — 31 Total recorded at fair value $836 $108 $— $ 944 $718 $90 $— $ 808 Assets recorded at NAV (1) Common/collective trust funds 689 621 Alternative investments: Real estate funds 9 9 Private equity funds 73 59 Debt funds 11 12 Hedge funds 1 1 Total recorded at NAV $ 783 $ 702 Total investments (2) $ 1,727 $1,510 Dominion Energy Gas Common and preferred stocks: U.S. $130 $ — $— $ 130 $121 $— $— $ 121 International 33 — — 33 24 — — 24 Total recorded at fair value $163 $ — $— $ 163 $145 $— $— $ 145 Assets recorded at NAV (1) Common/collective trust funds 154 140 Alternative investments: Real estate funds 1 1 Private equity funds 15 12 Debt funds — 1 Total recorded at NAV $ 170 $ 154 Total investments $ 333 $ 299 (1) These investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy. (2) Excludes net assets related to pending sales of securities of $1 million, net accrued income of $2 million, and includes net assets related to pending purchases of securities of $1 million at December 31, 2017. Excludes net assets related to pending sales of securities of $5 million, net accrued income of $2 million, and includes net assets related to pending purchases of securities of $5 million at December 31, 2016. The Plan’s investments are determined based on the fair values of the investments and the underlying investments, which have been determined as follows: • Cash and Cash Equivalents • Common and Preferred Stocks • Insurance Contracts • Corporate Debt Instruments • Government Securities • Common/Collective Trust Funds • Alternative Investments N ET ERIODIC ENEFIT REDIT OST The service cost component and non-service cost components of net periodic benefit (credit) cost are reflected in other operations and maintenance expense and other income, respectively, in the Consolidated Statements of Income. The components of the provision for net periodic benefit (credit) cost and amounts recognized in other comprehensive income and regulatory assets and liabilities for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans are as follows: Pension Benefits Other Postretirement Benefits Year Ended December 31, 2017 2016 2015 2017 2016 2015 (millions, except percentages) Dominion Energy Service cost $ 138 $ 118 $ 126 $ 26 $ 31 $ 40 Interest cost 345 317 287 60 65 67 Expected return on plan assets (639 ) (573 ) (531 ) (128 ) (118 ) (117 ) Amortization of prior service (credit) cost 1 1 2 (51 ) (35 ) (27 ) Amortization of net actuarial loss 162 111 160 13 8 6 Settlements and curtailments — 1 — — — — Net periodic benefit (credit) cost $ 7 $ (25 ) $ 44 $ (80 ) $ (49 ) $ (31 ) Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities: Current year net actuarial (gain) loss $ 142 $ 931 $ 159 $ 12 $ 178 $ (18 ) Prior service (credit) cost 5 — — (73 ) (216 ) (31 ) Settlements and curtailments 1 (1 ) — 2 — — Less amounts included in net periodic benefit cost: Amortization of net actuarial loss (162 ) (111 ) (160 ) (13 ) (8 ) (6 ) Amortization of prior service credit (cost) (1 ) (1 ) (2 ) 51 35 27 Total recognized in other comprehensive income and regulatory assets and liabilities $ (15 ) $ 818 $ (3 ) $ (21 ) $ (11 ) $ (28 ) Significant assumptions used to determine periodic cost: Discount rate 3.31%-4.50 % 2.87%-4.99 % 4.40 % 3.92%-4.47 % 3.56%-4.94 % 4.40 % Expected long-term rate of return on plan assets 8.75 % 8.75 % 8.75 % 8.50 % 8.50 % 8.50 % Weighted average rate of increase for compensation 4.09 % 4.22 % 4.22 % 3.29 % 4.22 % 4.22 % Healthcare cost trend rate (1) 7.00 % 7.00 % 7.00 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) (1) 5.00 % 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate (1)(2) 2021 2020 2019 Dominion Energy Gas Service cost $ 15 $ 13 $ 15 $ 4 $ 5 $ 7 Interest cost 30 30 27 12 14 14 Expected return on plan assets (141 ) (134 ) (126 ) (24 ) (23 ) (24 ) Amortization of prior service (credit) cost — — 1 (3 ) 1 (1 ) Amortization of net actuarial loss 16 13 20 2 1 2 Net periodic benefit (credit) cost $ (80 ) $ (78 ) $ (63 ) $ (9 ) $ (2 ) $ (2 ) Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities: Current year net actuarial (gain) loss $ (75 ) $ 91 $ 97 $ 18 $ 28 $ (9 ) Prior service cost — — — (61 ) — — Less amounts included in net periodic benefit cost: Amortization of net actuarial loss (16 ) (13 ) (20 ) (2 ) (1 ) (2 ) Amortization of prior service credit (cost) — — (1 ) 3 (1 ) 1 Total recognized in other comprehensive income and regulatory assets and liabilities $ (91 ) $ 78 $ 76 $ (42 ) $ 26 $ (10 ) Significant assumptions used to determine periodic cost: Discount rate 4.50 % 4.99 % 4.40 % 4.47 % 4.93 % 4.40 % Expected long-term rate of return on plan assets 8.75 % 8.75 % 8.75 % 8.50 % 8.50 % 8.50 % Weighted average rate of increase for compensation 4.11 % 3.93 % 3.93 % 4.11 % 3.93 % 3.93 % Healthcare cost trend rate (1) 7.00 % 7.00 % 7.00 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) (1) 5.00 % 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate (1)(2) 2021 2020 2019 (1) Assumptions used to determine net periodic cost for the following year. (2) The Society of Actuaries model used to determine healthcare cost trend rates was updated in 2014. The new model converges to the ultimate trend rate much more quickly than previous models. The components of AOCI and regulatory assets and liabilities for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans that have not been recognized as components of net periodic benefit (credit) cost are as follows: Pension Benefits Other Postretirement Benefits At December 31, 2017 2016 2017 2016 (millions) Dominion Energy Net actuarial loss $ 3,181 $ 3,200 $ 283 $ 283 Prior service (credit) cost 8 4 (440 ) (419 ) Total (1) $ 3,189 $ 3,204 $ (157 ) $ (136 ) Dominion Energy Gas Net actuarial loss $ 367 $ 458 $ 76 $ 60 Prior service (credit) cost — — (52 ) 7 Total (2) $ 367 $ 458 $ 24 $ 67 (1) As of December 31, 2017, of the $3.2 billion and $(157) million related to pension benefits and other postretirement benefits, $1.9 billion and $(87) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities. As of December 31, 2016, of the $3.2 billion and $(136) million related to pension benefits and other postretirement benefits, $1.9 billion and $(103) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities. (2) As of December 31, 2017, of the $367 million related to pension benefits, $134 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $24 million related to other postretirement benefits is included entirely in regulatory assets and liabilities. As of December 31, 2016, of the $458 million related to pension benefits, $167 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $67 million related to other postretirement benefits is included entirely in regulatory assets and liabilities. The following table provides the components of AOCI and regulatory assets and liabilities for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans as of December 31, 2017 that are expected to be amortized as components of net periodic benefit (credit) cost in 2018: Pension Benefits Other Benefits (millions) Dominion Energy Net actuarial loss $193 $ 11 Prior service (credit) cost 1 (52 ) Dominion Energy Gas Net actuarial loss $ 19 $ 3 Prior service (credit) cost — (4 ) The expected long-term rates of return on plan assets, discount rates, healthcare cost trend rates and mortality are critical assumptions in determining net periodic benefit (credit) cost. Dominion Energy develops non-investment Dominion Energy determines the expected long-term rates of return on plan assets for its pension plans and other postretirement benefit plans, including those in which Dominion Energy Gas participates, by using a combination of: • Expected inflation and risk-free interest rate assumptions; • Historical return analysis to determine long term historic returns as well as historic risk premiums for various asset classes; • Expected future risk premiums, asset volatilities and correlations; • Forward-looking return expectations derived from the yield on long-term bonds and the expected long-term returns of major stock market indices; and • Investment allocation of plan assets. Dominion Energy determines discount rates from analyses of AA/Aa rated bonds with cash flows matching the expected payments to be made under its plans, including those in which Dominion Energy Gas participates. Mortality rates are developed from actual and projected plan experience for postretirement benefit plans. Dominion Energy’s actuary conducts an experience study periodically as part of the process to select its best estimate of mortality. Dominion Energy considers both standard mortality tables and improvement factors as well as the plans’ actual experience when selecting a best estimate. During 2016, Dominion Energy conducted a new experience study as scheduled and, as a result, updated its mortality assumptions for all its plans, including those in which Dominion Energy Gas participates. Assumed healthcare cost trend rates have a significant effect on the amounts reported for Dominion Energy’s retiree healthcare plans, including those in which Dominion Energy Gas participates. A one percentage point change in assumed healthcare cost trend rates would have had the following effects for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) other postretirement benefit plans: Other Postretirement Benefits One percentage point increase One percentage point decrease (millions) Dominion Energy Effect on net periodic cost for 2018 $ 24 $ (15 ) Effect on other postretirement benefit obligation at December 31, 2017 158 (132 ) Dominion Energy Gas Effect on net periodic cost for 2018 $ 4 $ (3 ) Effect on other postretirement benefit obligation at December 31, 2017 31 (26 ) Dominion Energy Gas (Employees Not Represented by Collective Bargaining Units) and Virginia Power—Participation in Defined Benefit Plans Virginia Power employees and Dominion Energy Gas employees not represented by collective bargaining units are covered by the Dominion Energy Pension Plan described above. As participating employers, Virginia Power and Dominion Energy Gas are subject to Dominion Energy’s funding policy, which is to contribute annually an amount that is in accordance with ERISA. During 2017, Virginia Power and Dominion Energy Gas made no contributions to the Dominion Energy Pension Plan, and no contributions to this plan are currently expected in 2018. Virginia Power’s net periodic pension cost related to this plan was $110 million, $79 million and $97 million in 2017, 2016 and 2015, respectively. Dominion Energy Gas’ net periodic pension credit related to this plan was $(37) million, $(45) million and $(38) million in 2017, 2016 and 2015, respectively. Net periodic pension (credit) cost is reflected in other operations and maintenance expense in their respective Consolidated Statements of Income. The funded status of various Dominion Energy subsidiary groups and employee compensation are the basis for determining the share of total pension costs for participating Dominion Energy subsidiaries. See Note 24 for Virginia Power and Dominion Energy Gas amounts due to/from Dominion Energy related to this plan. Retiree healthcare and life insurance benefits, for Virginia Power employees and for Dominion Energy Gas employees not represented by collective bargaining units, are covered by the Dominion Energy Retiree Health and Welfare Plan described abov

COMMITMENTS ANDCONTINGENCIES

COMMITMENTS ANDCONTINGENCIES	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS ANDCONTINGENCIES	N OTE OMMITMENTS ND ONTINGENCIES As a result of issues generated in the ordinary course of business, the Companies are involved in legal proceedings before various courts and are periodically subject to governmental examinations (including by regulatory authorities), inquiries and investigations. Certain legal proceedings and governmental examinations involve demands for unspecified amounts of damages, are in an initial procedural phase, involve uncertainty as to the outcome of pending appeals or motions, or involve significant factual issues that need to be resolved, such that it is not possible for the Companies to estimate a range of possible loss. For such matters for which the Companies cannot estimate a range of possible loss, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the litigation or investigative processes such that the Companies are able to estimate a range of possible loss. For legal proceedings and governmental examinations for which the Companies are able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any accrued liability is recorded on a gross basis with a receivable also recorded for any probable insurance recoveries. Estimated ranges of loss are inclusive of legal fees and net of any anticipated insurance recoveries. Any estimated range is based on currently available information and involves elements of judgment and significant uncertainties. Any estimated range of possible loss may not represent the Companies’ maximum possible loss exposure. The circumstances of such legal proceedings and governmental examinations will change from time to time and actual results may vary significantly from the current estimate. For current proceedings not specifically reported below, management does not anticipate that the liabilities, if any, arising from such proceedings would have a material effect on the financial position, liquidity or results of operations of the Companies. Environmental Matters The Companies are subject to costs resulting from a number of federal, state and local laws and regulations designed to protect human health and the environment. These laws and regulations affect future planning and existing operations. They can result in increased capital, operating and other costs as a result of compliance, remediation, containment and monitoring obligations. A IR CAA The CAA, as amended, is a comprehensive program utilizing a broad range of regulatory tools to protect and preserve the nation’s air quality. At a minimum, states are required to establish regulatory programs to address all requirements of the CAA. However, states may choose to develop regulatory programs that are more restrictive. Many of the Companies’ facilities are subject to the CAA’s permitting and other requirements. MATS The MATS rule requires coal- and oil-fired one-year one-year 90-day Although litigation of the MATS rule is still pending, the regulation remains in effect and Virginia Power is complying with the applicable requirements of the rule and does not expect any adverse impacts to its operations at this time. Ozone Standards In October 2015, the EPA issued a final rule tightening the ozone standard from 75-ppb 70-ppb. X X X mid-2019 The statutory deadline for the EPA to complete attainment designations for a new standard was October 2017. States will have three years after final designations, certain of which were issued by the EPA in November 2017, to develop plans to address the new standard. Until the states have developed implementation plans for the standard, the Companies are unable to predict whether or to what extent the new rules will ultimately require additional controls. The expenditures required to implement additional controls could have a material impact on the Companies’ results of operations and cash flows. NO x In April 2016, the Pennsylvania Department of Environmental Protection issued final regulations, with an effective date of January 2017, to reduce NO X Oil and Gas NSPS In August 2012, the EPA issued an NSPS impacting new and modified facilities in the natural gas production and gathering sectors and made revisions to the NSPS for natural gas processing and transmission facilities. These rules establish equipment performance specifications and emissions standards for control of VOC emissions for natural gas production wells, tanks, pneumatic controllers, and compressors in the upstream sector. In June 2016, the EPA issued a new NSPS regulation, for the oil and natural gas sector, to regulate methane and VOC emissions from new and modified facilities in transmission and storage, gathering and boosting, production and processing facilities. All projects which commenced construction after September 2015 are required to comply with this regulation. In April 2017, the EPA issued a notice that it is reviewing the rule and, if appropriate, will issue a rulemaking to suspend, revise or rescind the June 2016 final NSPS for certain oil and gas facilities. In June 2017, the EPA published notice of reconsideration and partial stay of the rule for 90 days and proposed extending the stay for two years. In July 2017, the U.S. Court of Appeals for the D.C. Circuit vacated the 90-day two-year GHG R EGULATION Carbon Regulations In August 2016, the EPA issued a draft rule proposing to reaffirm that a source’s obligation to obtain a PSD or Title V permit for GHGs is triggered only if such permitting requirements are first triggered by non-GHG, 2 In addition, the EPA continues to evaluate its policy regarding the consideration of CO 2 Methane Emissions In July 2015, the EPA announced the next generation of its voluntary Natural Gas STAR Program, the Natural Gas STAR Methane Challenge Program. The program covers the entire natural gas sector from production to distribution, with more emphasis on transparency and increased reporting for both annual emissions and reductions achieved through implementation measures. In March 2016, East Ohio, Hope, DETI and Questar Gas joined the EPA as founding partners in the new Methane Challenge program and submitted implementation plans in September 2016. DECG joined the EPA’s voluntary Natural Gas STAR Program in July 2016 and submitted an implementation plan in September 2016. Dominion Energy and Dominion Energy Gas do not expect the costs related to these programs to have a material impact on their results of operations, financial condition and/or cash flows. W ATER The CWA, as amended, is a comprehensive program requiring a broad range of regulatory tools including a permit program to authorize and regulate discharges to surface waters with strong enforcement mechanisms. The Companies must comply with applicable aspects of the CWA programs at their operating facilities. In October 2014, the final regulations under Section 316(b) of the CWA that govern existing facilities and new units at existing facilities that employ a cooling water intake structure and that have flow levels exceeding a minimum threshold became effective. The rule establishes a national standard for impingement based on seven compliance options, but forgoes the creation of a single technology standard for entrainment. Instead, the EPA has delegated entrainment technology decisions to state regulators. State regulators are to make case-by-case case-by-case In September 2015, the EPA released a final rule to revise the Effluent Limitations Guidelines for the Steam Electric Power Generating Category. The final rule establishes updated standards for wastewater discharges that apply primarily at coal and oil steam generating stations. Affected facilities are required to convert from wet to dry or closed cycle coal ash management, improve existing wastewater treatment systems and/or install new wastewater treatment technologies in order to meet the new discharge limits. Virginia Power has eight facilities subject to the final rule. In April 2017, the EPA granted two separate petitions for reconsideration of the Effluent Limitations Guidelines final rule and stayed future compliance dates in the rule. Also in April 2017, the U.S. Court of Appeals for the Fifth Circuit granted the U.S.’s request for a stay of the pending consolidated litigation challenging the rule while the EPA addresses the petitions for reconsideration. In September 2017, the EPA signed a rule to postpone the earliest compliance dates for certain waste streams regulations in the Effluent Limitations Guidelines final rule from November 2018 to November 2020; however, the latest date for compliance for these regulations remains December 2023. The EPA is proposing to complete new rulemaking for these waste streams. While the impacts of this rule could be material to Dominion Energy’s and Virginia Power’s results of operations, financial condition and/or cash flows, the existing regulatory framework in Virginia provides rate recovery mechanisms that could substantially mitigate any such impacts for Virginia Power. W ASTE ANAGEMENT AND EMEDIATION The CERCLA, as amended, provides for immediate response and removal actions coordinated by the EPA in the event of threatened releases of hazardous substances into the environment and authorizes the U.S. government either to clean up sites at which hazardous substances have created actual or potential environmental hazards or to order persons responsible for the situation to do so. Under the CERCLA, as amended, generators and transporters of hazardous substances, as well as past and present owners and operators of contaminated sites, can be jointly, severally and strictly liable for the cost of cleanup. These potentially responsible parties can be ordered to perform a cleanup, be sued for costs associated with an EPA-directed From time to time, Dominion Energy, Virginia Power, or Dominion Energy Gas may be identified as a potentially responsible party to a Superfund site. The EPA (or a state) can either allow such a party to conduct and pay for a remedial investigation, feasibility study and remedial action or conduct the remedial investigation and action itself and then seek reimbursement from the potentially responsible parties. These parties can also bring contribution actions against each other and seek reimbursement from their insurance companies. As a result, Dominion Energy, Virginia Power, or Dominion Energy Gas may be responsible for the costs of remedial investigation and actions under the Superfund law or other laws or regulations regarding the remediation of waste. The Companies do not believe these matters will have a material effect on results of operations, financial condition and/or cash flows. Dominion Energy has determined that it is associated with 19 former manufactured gas plant sites, three of which pertain to Virginia Power and 12 of which pertain to Dominion Energy Gas. Studies conducted by other utilities at their former manufactured gas plant sites have indicated that those sites contain coal tar and other potentially harmful materials. None of the former sites with which the Companies are associated is under investigation by any state or federal environmental agency. At one of the former sites, Dominion Energy is conducting a state-approved post closure groundwater monitoring program and an environmental land use restriction has been recorded. Another site has been accepted into a state-based voluntary remediation program. Virginia Power is currently evaluating the nature and extent of the contamination from this site as well as potential remedial options. Preliminary costs for options under evaluation for the site range from $1 million to $22 million. Due to the uncertainty surrounding the other sites, the Companies are unable to make an estimate of the potential financial statement impacts. See below for discussion on ash pond and landfill closure costs. Other Legal Matters The Companies are defendants in a number of lawsuits and claims involving unrelated incidents of property damage and personal injury. Due to the uncertainty surrounding these matters, the Companies are unable to make an estimate of the potential financial statement impacts; however, they could have a material impact on results of operations, financial condition and/or cash flows. A PPALACHIAN ATEWAY Pipeline Contractor Litigation Following the completion of the Appalachian Gateway project in 2012, DETI received multiple change order requests and other claims for additional payments from a pipeline contractor for the project. In July 2015, the contractor filed a complaint against DETI in U.S. District Court for the Western District of Pennsylvania. In March 2016, the Pennsylvania court granted DETI’s motion to transfer the case to the U.S. District Court for the Eastern District of Virginia. In July 2016, DETI filed a motion to dismiss. In March 2017, the court dismissed three of eight counts in the complaint. In May 2017, the contractor withdrew one of the counts in the complaint. In November 2017, DETI and the contractor entered into a partial settlement agreement for a release of certain claims. This case is pending. At December 31, 2017, DETI has accrued a liability of $2 million for this matter. Dominion Energy Gas cannot currently estimate additional financial statement impacts, but there could be a material impact to its financial condition and/or cash flows. Gas Producers Litigation In connection with the Appalachian Gateway project, Dominion Energy Field Services, Inc. entered into contracts for firm purchase rights with a group of small gas producers. In June 2016, the gas producers filed a complaint in the Circuit Court of Marshall County, West Virginia against Dominion Energy, DETI and Dominion Energy Field Services, Inc., among other defendants, claiming that the contracts are unenforceable and seeking compensatory and punitive damages. During the third quarter of 2016, Dominion Energy, DETI and Dominion Energy Field Services, Inc. were served with the complaint. Also in the third quarter of 2016, Dominion Energy and DETI, with the consent of the other defendants, removed the case to the U.S. District Court for the Northern District of West Virginia. In October 2016, the defendants filed a motion to dismiss and the plaintiffs filed a motion to remand. In February 2017, the U.S. District Court entered an order remanding the matter to the Circuit Court of Marshall County, West Virginia. In March 2017, Dominion Energy was voluntarily dismissed from the case; however, DETI and Dominion Energy Field Services, Inc. remain parties to the matter. In April 2017, the case was transferred to the Business Court Division of West Virginia. In January 2018, the court granted the motion to dismiss filed by the defendants on two counts. All other claims are pending in the Business Court Division of West Virginia. Dominion Energy and Dominion Energy Gas cannot currently estimate financial statement impacts, but there could be a material impact to their financial condition and/or cash flows. A SH OND AND ANDFILL LOSURE OSTS In March 2015, the Sierra Club filed a lawsuit alleging CWA violations at Chesapeake power station. In March 2017, the U.S. District Court for the Eastern District of Virginia ruled that impacted groundwater associated with the on-site on-site In April 2015, the EPA enacted a final rule regulating CCR landfills, existing ash ponds that still receive and manage CCRs, and inactive ash ponds that do not receive, but still store, CCRs. Virginia Power currently operates inactive ash ponds, existing ash ponds, and CCR landfills subject to the final rule at eight different facilities. This rule created a legal obligation for Virginia Power to retrofit or close all of its inactive and existing ash ponds over a certain period of time, as well as perform required monitoring, corrective action, and post-closure care activities as necessary. In 2015, Virginia Power recorded a $386 million ARO related to future ash pond and landfill closure costs, which resulted in a $99 million incremental charge recorded in other operations and maintenance expense in its Consolidated Statement of Income, a $166 million increase in property, plant and equipment associated with asset retirement costs, and a $121 million reduction in other noncurrent liabilities from the reversal of a previously recorded contingent liability since the ARO obligation created by the final CCR rule represents similar activities. In 2016, Virginia Power recorded an increase to this ARO of $238 million, which resulted in a $197 million incremental charge recorded in other operations and maintenance expense in its Consolidated Statement of Income, a $17 million increase in property, plant and equipment and a $24 million increase in regulatory assets. In December 2016, legislation was enacted that creates a framework for EPA- In April 2017, the Virginia Governor signed legislation into law that places a moratorium on the VDEQ issuing solid waste permits for closure of ash ponds at Virginia Power’s Bremo, Chesapeake, Chesterfield and Possum Point power stations until May 2018. The law also required Virginia Power to conduct an assessment of closure alternatives for the ash ponds at these four stations, to include an evaluation of excavation for recycling or off-site C OVE OINT Dominion Energy has constructed the Liquefaction Project at the Cove Point facility, which, once commercially operational, would enable the facility to liquefy domestically-produced natural gas and export it as LNG. In September 2014, FERC issued an order granting authorization for Cove Point to construct, modify and operate the Liquefaction Project. Two parties have separately filed petitions for review of the FERC order in the U.S. Court of Appeals for the D.C. Circuit, which petitions were consolidated. Separately, one party requested a stay of the FERC order until the judicial proceedings are complete, which the court denied in June 2015. In July 2016, the court denied one party’s petition for review of the FERC order authorizing the Liquefaction Project. The court also issued a decision remanding the other party’s petition for review of the FERC order to FERC for further explanation of FERC’s decision that a previous transaction with an existing import shipper was not unduly discriminatory. In September 2017, FERC issued its order on remand from the U.S. Court of Appeals for the D.C. Circuit, and reaffirmed its ruling in its prior orders that Cove Point did not violate the prohibition against undue discrimination by agreeing to a capacity reduction and early contract termination with the existing import shipper. In October 2017, the party filed a request for rehearing of the FERC order on remand. This case is pending. In September 2013, the DOE granted Non-FTA In July 2017, Cove Point submitted an application for a temporary operating permit to the Maryland Department of the Environment, as required prior to the date of first production of LNG for commercial purposes of exporting LNG. The permit was received in December 2017. In February 2018, the Public Service Commission of Maryland issued an order approving Cove Point’s August 2017 application to amend the CPCN issued by the Public Service Commission of Maryland in May 2014 to make necessary updates. FERC FERC staff in the Office of Enforcement, Division of Investigations, is conducting a non-public day-ahead G REENSVILLE OUNTY Virginia Power is constructing Greensville County and related transmission interconnection facilities. In August 2016, the Sierra Club filed an administrative appeal in the Circuit Court for the City of Richmond challenging certain provisions in Greensville County’s PSD air permit issued by VDEQ in June 2016. In August 2017, the Circuit Court upheld the air permit, and no appeals were filed. Nuclear Matters In March 2011, a magnitude 9.0 earthquake and subsequent tsunami caused significant damage at the Fukushima Daiichi nuclear power station in northeast Japan. These events have resulted in significant nuclear safety reviews required by the NRC and industry groups such as the Institute of Nuclear Power Operations. Like other U.S. nuclear operators, Dominion Energy has been gathering supporting data and participating in industry initiatives focused on the ability to respond to and mitigate the consequences of design-basis and beyond-design-basis events at its stations. In July 2011, an NRC task force provided initial recommendations based on its review of the Fukushima Daiichi accident and in October 2011 the NRC staff prioritized these recommendations into Tiers 1, 2 and 3, with the Tier 1 recommendations consisting of actions which the staff determined should be started without unnecessary delay. In December 2011, the NRC Commissioners approved the agency staff’s prioritization and recommendations, and that same month an appropriations act directed the NRC to require reevaluation of external hazards (not limited to seismic and flooding hazards) as soon as possible. Based on the prioritized recommendations, in March 2012, the NRC issued orders and information requests requiring specific reviews and actions to all operating reactors, construction permit holders and combined license holders based on the lessons learned from the Fukushima Daiichi event. The orders applicable to Dominion Energy requiring implementation of safety enhancements related to mitigation strategies to respond to extreme natural events resulting in the loss of power at plants, and enhancing spent fuel pool instrumentation have been implemented. The information requests issued by the NRC request each reactor to reevaluate the seismic and external flooding hazards at their site using present-day Nuclear Operations N UCLEAR ECOMMISSIONING INIMUM INANCIAL SSURANCE The NRC requires nuclear power plant owners to annually update minimum financial assurance amounts for the future decommissioning of their nuclear facilities. Decommissioning involves the decontamination and removal of radioactive contaminants from a nuclear power station once operations have ceased, in accordance with standards established by the NRC. The 2017 calculation for the NRC minimum financial assurance amount, aggregated for Dominion Energy’s and Virginia Power’s nuclear units, excluding joint owners’ assurance amounts and Millstone Unit 1 and Kewaunee, as those units are in a decommissioning state, was $2.7 billion and $1.8 billion, respectively, and has been satisfied by a combination of the funds being collected and deposited in the nuclear decommissioning trusts and the real annual rate of return growth of the funds allowed by the NRC. The 2017 NRC minimum financial assurance amounts above were calculated using preliminary December 31, 2017 U.S. Bureau of Labor Statistics indices. Dominion Energy believes that the amounts currently available in its decommissioning trusts and their expected earnings will be sufficient to cover expected decommissioning costs for the Millstone and Kewaunee units. Virginia Power also believes that the decommissioning funds and their expected earnings for the Surry and North Anna units will be sufficient to cover decommissioning costs, particularly when combined with future ratepayer collections and contributions to these decommissioning trusts, if such future collections and contributions are required. This reflects a positive long-term outlook for trust fund investment returns as the decommissioning of the units will not be complete for decades. Dominion Energy and Virginia Power will continue to monitor these trusts to ensure they meet the NRC minimum financial assurance requirement, which may include, if needed, the use of parent company guarantees, surety bonding or other financial instruments recognized by the NRC. See Note 9 for additional information on nuclear decommissioning trust investments. N UCLEAR NSURANCE The Price-Anderson Amendments Act of 1988 provides the public up to $13.44 billion of liability protection per nuclear incident, via obligations required of owners of nuclear power plants, and allows for an inflationary provision adjustment every five years. Dominion Energy and Virginia Power have purchased $450 million of coverage from commercial insurance pools for each reactor site with the remainder provided through a mandatory industry retrospective rating plan. In the event of a nuclear incident at any licensed nuclear reactor in the U.S., the Companies could be assessed up to $127 million for each of their licensed reactors not to exceed $19 million per year per reactor. There is no limit to the number of incidents for which this retrospective premium can be assessed. However, the NRC granted an exemption in March 2015 to remove Kewaunee from the Secondary Financial Protection program. The current levels of nuclear property insurance coverage for Dominion Energy’s and Virginia Power’s nuclear units are as follows: Coverage (billions) Dominion Energy Millstone $1.70 Kewaunee 1.06 Virginia Power (1) Surry $1.70 North Anna 1.70 (1) Surry and North Anna share a blanket property limit of $200 million. Dominion Energy’s and Virginia Power’s nuclear property insurance coverage for Millstone, Surry and North Anna exceeds the NRC minimum requirement for nuclear power plant licensees of $1.06 billion per reactor site. Kewaunee meets the NRC minimum requirement of $1.06 billion. This includes coverage for premature decommissioning and functional total loss. The NRC requires that the proceeds from this insurance be used first, to return the reactor to and maintain it in a safe and stable condition and second, to decontaminate the reactor and station site in accordance with a plan approved by the NRC. Nuclear property insurance is provided by NEIL, a mutual insurance company, and is subject to retrospective premium assessments in any policy year in which losses exceed the funds available to the insurance company. Dominion Energy’s and Virginia Power’s maximum retrospective premium assessment for the current policy period is $86 million and $50 million, respectively. Based on the severity of the incident, the Board of Directors of the nuclear insurer has the discretion to lower or eliminate the maximum retrospective premium assessment. Dominion Energy and Virginia Power have the financial responsibility for any losses that exceed the limits or for which insurance proceeds are not available because they must first be used for stabilization and decontamination. Millstone and Virginia Power also purchase accidental outage insurance from NEIL to mitigate certain expenses, including replacement power costs, associated with the prolonged outage of a nuclear unit due to direct physical damage. Under this program, Dominion Energy and Virginia Power are subject to a retrospective premium assessment for any policy year in which losses exceed funds available to NEIL. Dominion Energy’s and Virginia Power’s maximum retrospective premium assessment for the current policy period is $22 million and $10 million, respectively. ODEC, a part owner of North Anna, and Massachusetts Municipal and Green Mountain, part owners of Millstone’s Unit 3, are responsible to Dominion Energy and Virginia Power for their share of the nuclear decommissioning obligation and insurance premiums on applicable units, including any retrospective premium assessments and any losses not covered by insurance. S PENT UCLEAR UEL Dominion Energy and Virginia Power entered into contracts with the DOE for the disposal of spent nuclear fuel under provisions of the Nuclear Waste Policy Act of 1982. The DOE failed to begin accepting the spent fuel on January 31, 1998, the date provided by the Nuclear Waste Policy Act and by Dominion Energy’s and Virginia Power’s contracts with the DOE. Dominion Energy and Virginia Power have previously received damages award payments and settlement payments related to these contracts. By mutual agreement of the parties, the settlement agreements are extendable to provide for resolution of damages incurred after 2013. The settlement agreements for the Surry, North Anna and Millstone plants have been extended to provide for periodic payments for damages incurred through December 31, 2016, and have been extended to provide for periodic payment of damages through December 31, 2019. Pursuit of or possible settlement of the Kewaunee claims for damages incurred after December 31, 2013 is being evaluated. In 2017, Virginia Power and Dominion Energy received payments of $22 million for resolution of claims incurred at North Anna and Surry for the period of January 1, 2015 through December 31, 2015, and $14 million for resolution of claims incurred at Millstone for the period of July 1, 2015 through June 30, 2016. In 2016, Virginia Power and Dominion Energy received payments of $30 million for resolution of claims incurred at North Anna and Surry for the period of January 1, 2014 through December 31, 2014, and $22 million for resolution of claims incurred at Millstone for the period of July 1, 2014 through June 30, 2015. In 2015, Virginia Power and Dominion Energy received payments of $8 million for resolution of claims incurred at North Anna and Surry for the period of January 1, 2013 through December 31, 2013, and $17 million for resolution of claims incurred at Millstone for the period of July 1, 2013 through June 30, 2014. Dominion Energy and Virginia Power continue to recognize receivables for certain spent nuclear fuel-related costs that they believe are probable of recovery from the DOE. Dominion Energy’s receivables for spent nuclear fuel-related costs totaled $46 million and $56 million at December 31, 2017 and 2016, respectively. Virginia Power’s receivables for spent nuclear fuel-related costs totaled $30 million and $37 million at December 31, 2017 and 2016, respectively. Dominion Energy and Virginia Power will continue to manage their spent fuel until it is accepted by the DOE. Long-Term Purchase Agreements At December 31, 2017, Virginia Power had the following long-term commitments that are noncancelable or are cancelable only under certain conditions, and that a third party has used to secure financing for the facility that will provide the contracted goods or services: 2018 2019 2020 2021 2022 Thereafter Total (millions) Purchased electric capacity (1) $ 93 $ 61 $ 52 $ 46 $— $— $ 252 (1) Commitments represent estimated amounts payable for capacity under a power purchase contract with a qualifying facility and an independent power producer, which ends in 2021. Capacity payments under the contract are generally based on fixed dollar amounts per month, subject to escalation using broad-based economic indices. At December 31, 2017, the present value of Virginia Power’s total commitment for capacity payments is $221 million. Capacity payments totaled $114 million, $248 million, and $305 million, and energy payments totaled $72 million, $126 million, and $198 million for the years ended 2017, 2016 and 2015, respectively. Lease Commitments The Companies lease real estate, vehicles and equipment primarily under operating leases. Payments under certain leases are escalated based on an index such as the consumer price index. Future minimum lease payments under noncancelable operating and capital leases that have initial or remaining lease terms in excess of one year as of December 31, 2017 are as follows: 2018 2019 2020 2021 2022 Thereafter Total (millions) Dominion Energy (1) $ 68 $ 63 $ 56 $ 48 $ 39 $361 $ 635 Virginia Power $ 34 $ 31 $ 27 $ 22 $ 15 $ 28 $ 157 Dominion Energy Gas $ 15 $ 13 $ 10 $ 9 $ 7 $ 41 $ 95 (1) Amounts include a lease agreement for the Dominion Energy Questar corporate office, which is accounted for as a capital lease. At December 31, 2017 and 2016, the Consolidated Balance Sheets include $27 million and $30 million, respectively, in property, plant and equipment and $33 million and $35 million, respectively, in other deferred credits and other liabilities. The Consolidated Statements of Income include $3 million and less than $1 million recorded in depreciation, depletion and amortization for the years ended December 31, 2017 and 2016. Rental expense for Dominion Energy totaled $113 million, $104 million, and $99 million for 2017, 2016 and 2015, respectively. Rental expense for Virginia Power totaled $57 million, $52 million, and $51 million for 2017, 2016 and 2015, respectively. Rental expense for Dominion Energy Gas totaled $34 million, $37 million, and $37 million for 2017, 2016 and 2015, respectively. The majority of rental expense i

Credit Risk

Credit Risk	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Credit Risk	N OTE REDIT ISK Credit risk is the risk of financial loss if counterparties fail to perform their contractual obligations. In order to minimize overall credit risk, credit policies are maintained, including the evaluation of counterparty financial condition, collateral requirements and the use of standardized agreements that facilitate the netting of cash flows associated with a single counterparty. In addition, counterparties may make available collateral, including letters of credit or cash held as margin deposits, as a result of exceeding agreed-upon credit limits, or may be required to prepay the transaction. The Companies maintain a provision for credit losses based on factors surrounding the credit risk of their customers, historical trends and other information. Management believes, based on credit policies and the December 31, 2017 provision for credit losses, that it is unlikely that a material adverse effect on financial position, results of operations or cash flows would occur as a result of counterparty nonperformance. General D OMINION NERGY As a diversified energy company, Dominion Energy transacts primarily with major companies in the energy industry and with commercial and residential energy consumers. These transactions principally occur in the Northeast, mid-Atlantic, Dominion Energy’s exposure to credit risk is concentrated primarily within its energy marketing and price risk management activities, as Dominion Energy transacts with a smaller, less diverse group of counterparties and transactions may involve large notional volumes and potentially volatile commodity prices. Energy marketing and price risk management activities include marketing of merchant generation output, structured transactions and the use of financial contracts for enterprise-wide hedging purposes. Gross credit exposure for each counterparty is calculated as outstanding receivables plus any unrealized on- off-balance non-investment V IRGINIA OWER Virginia Power sells electricity and provides distribution and transmission services to customers in Virginia and northeastern North Carolina. Management believes that this geographic concentration risk is mitigated by the diversity of Virginia Power’s customer base, which includes residential, commercial and industrial customers, as well as rural electric cooperatives and municipalities. Credit risk associated with trade accounts receivable from energy consumers is limited due to the large number of customers. Virginia Power’s exposure to potential concentrations of credit risk results primarily from sales to wholesale customers. Virginia Power’s gross credit exposure for each counterparty is calculated as outstanding receivables plus any unrealized on- off-balance non-investment D OMINION NERGY AS Dominion Energy Gas transacts mainly with major companies in the energy industry and with residential and commercial energy consumers. These transactions principally occur in the Northeast, mid-Atlantic on- off-balance non-investment In 2017, DETI provided service to 289 customers with approximately 96% of its storage and transportation revenue being provided through firm services. The ten largest customers provided approximately 38% of the total storage and transportation revenue and the thirty largest provided approximately 68% of the total storage and transportation revenue. East Ohio distributes natural gas to residential, commercial and industrial customers in Ohio using rates established by the Ohio Commission. Approximately 98% of East Ohio revenues are derived from its regulated gas distribution services. East Ohio’s bad debt risk is mitigated by the regulatory framework established by the Ohio Commission. See Note 13 for further information about Ohio’s PIPP and UEX Riders that mitigate East Ohio’s overall credit risk. Credit-Related Contingent Provisions The majority of Dominion Energy’s derivative instruments contain credit-related contingent provisions. These provisions require Dominion Energy to provide collateral upon the occurrence of specific events, primarily a credit downgrade. If the credit-related contingent features underlying these instruments that are in a liability position and not fully collateralized with cash were fully triggered as of December 31, 2017 and 2016, Dominion Energy would have been required to post an additional $62 million and $3 million, respectively, of collateral to its counterparties. The collateral that would be required to be posted includes the impacts of any offsetting asset positions and any amounts already posted for derivatives, non-derivative non-derivative

RELATED-PARTYTRANSACTIONS

RELATED-PARTYTRANSACTIONS	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
RELATED-PARTYTRANSACTIONS	N OTE ELATED PARTY RANSACTIONS Virginia Power and Dominion Energy Gas engage in related party transactions primarily with other Dominion Energy subsidiaries (affiliates). Virginia Power’s and Dominion Energy Gas’ receivable and payable balances with affiliates are settled based on contractual terms or on a monthly basis, depending on the nature of the underlying transactions. Virginia Power and Dominion Energy Gas are included in Dominion Energy’s consolidated federal income tax return and, where applicable, combined income tax returns for Dominion Energy are filed in various states. See Note 2 for further information. Dominion Energy’s transactions with equity method investments are described in Note 9. A discussion of significant related party transactions follows. V IRGINIA OWER Transactions with Affiliates Virginia Power transacts with affiliates for certain quantities of natural gas and other commodities in the ordinary course of business. Virginia Power also enters into certain commodity derivative contracts with affiliates. Virginia Power uses these contracts, which are principally comprised of commodity swaps, to manage commodity price risks associated with purchases of natural gas. See Notes 7 and 19 for more information. As of December 31, 2017, Virginia Power’s derivative assets and liabilities with affiliates were $11 million and $5 million, respectively. As of December 31, 2016, Virginia Power’s derivative assets and liabilities with affiliates were $41 million and $8 million, respectively. Virginia Power participates in certain Dominion Energy benefit plans as described in Note 21. At December 31, 2017 and 2016, Virginia Power’s amounts due to Dominion Energy asso-ciated with the Dominion Energy Pension Plan and reflected in noncurrent pension and other postretirement benefit liabilities in the Consolidated Balance Sheets were $505 million and $396 million, respectively. At December 31, 2017 and 2016, Virginia Power’s amounts due from Dominion Energy associated with the Dominion Energy Retiree Health and Welfare Plan and reflected in noncurrent pension and other postretirement benefit assets in the Consolidated Balance Sheets were $199 million and $130 million, respectively. DES and other affiliates provide accounting, legal, finance and certain administrative and technical services to Virginia Power. In addition, Virginia Power provides certain services to affiliates, including charges for facilities and equipment usage. The financial statements for all years presented include costs for certain general, administrative and corporate expenses assigned by DES to Virginia Power on the basis of direct and allocated methods in accordance with Virginia Power’s services agreements with DES. Where costs incurred cannot be determined by specific identification, the costs are allocated based on the proportional level of effort devoted by DES resources that is attributable to the entity, determined by reference to number of employees, salaries and wages and other similar measures for the relevant DES service. Management believes the assumptions and methodologies underlying the allocation of general corporate overhead expenses are reasonable. Presented below are significant transactions with DES and other affiliates: Year Ended December 31, 2017 2016 2015 (millions) Commodity purchases from affiliates $ 674 $ 571 $ 555 Services provided by affiliates (1) 453 454 422 Services provided to affiliates 25 22 22 (1) Includes capitalized expenditures of $144 million, $144 million and $143 million for the year ended December 31, 2017, 2016 and 2015, respectively. Virginia Power has borrowed funds from Dominion Energy under short-term borrowing arrangements. There were $33 million and $262 million in short-term demand note borrowings from Dominion Energy as of December 31, 2017 and 2016, respectively. The weighted-average interest rate of these borrowings was 1.65% and 0.97% at December 31, 2017 and 2016, respectively. Virginia Power had no outstanding borrowings, net of repayments under the Dominion Energy money pool for its nonregulated subsidiaries as of December 31, 2017 and 2016. Interest charges related to Virginia Power’s borrowings from Dominion Energy were immaterial for the years ended December 31, 2017, 2016 and 2015. There were no issuances of Virginia Power’s common stock to Dominion Energy in 2017, 2016 or 2015. D OMINION NERGY AS Transactions with Related Parties Dominion Energy Gas transacts with affiliates for certain quantities of natural gas and other commodities at market prices in the ordinary course of business. Additionally, Dominion Energy Gas provides transportation and storage services to affiliates. Dominion Energy Gas also enters into certain other contracts with affiliates, which are presented separately from contracts involving commodities or services. As of December 31, 2017 and 2016, all of Dominion Energy Gas’ commodity derivatives were with affiliates. See Notes 7 and 19 for more information. See Note 9 for information regarding transactions with an affiliate. Dominion Energy Gas participates in certain Dominion Energy benefit plans as described in Note 21. At December 31, 2017 and 2016, Dominion Energy Gas’ amounts due from Dominion Energy associated with the Dominion Energy Pension Plan and reflected in noncurrent pension and other postretirement benefit assets in the Consolidated Balance Sheets were $734 million and $697 million, respectively. Dominion Energy Gas’ amounts due from Dominion Energy associated with the Dominion Energy Retiree Health and Welfare Plan and reflected in noncurrent pension and other postretirement benefit assets in the Consolidated Balance Sheets were $7 million and $2 million at December 31, 2017 and 2016, respectively. DES and other affiliates provide accounting, legal, finance and certain administrative and technical services to Dominion Energy Gas. Dominion Energy Gas provides certain services to related parties, including technical services. The financial statements for all years presented include costs for certain general, administrative and corporate expenses assigned by DES to Dominion Energy Gas on the basis of direct and allocated methods in accordance with Dominion Energy Gas’ services agreements with DES. Where costs incurred cannot be determined by specific identification, the costs are allocated based on the proportional level of effort devoted by DES resources that is attributable to the entity, determined by reference to number of employees, salaries and wages and other similar measures for the relevant DES service. Management believes the assumptions and methodologies underlying the allocation of general corporate overhead expenses are reasonable. The costs of these services follow: Year Ended December 31, 2017 2016 2015 (millions) Purchases of natural gas and transportation and storage services from affiliates $ 5 $ 9 $ 10 Sales of natural gas and transportation and storage services to affiliates 70 69 69 Services provided by related parties (1) 143 141 133 Services provided to related parties (2) 156 128 101 (1) Includes capitalized expenditures of $45 million, $49 million and $57 million for the year ended December 31, 2017, 2016 and 2015, respectively. (2) Amounts primarily attributable to Atlantic Coast Pipeline. The following table presents affiliated and related party balances reflected in Dominion Energy Gas’ Consolidated Balance Sheets: At December 31, 2017 2016 (millions) Other receivables (1) $ 12 $ 10 Customer receivables from related parties 1 1 Imbalances receivable from affiliates 1 2 Imbalances payable to affiliates (2) — 4 Affiliated notes receivable (3) 20 18 (1) Represents amounts due from Atlantic Coast Pipeline, a related party VIE. (2) Amounts are presented in other current liabilities in Dominion Energy Gas’ Consolidated Balance Sheets. (3) Amounts are presented in other deferred charges and other assets in Dominion Energy Gas’ Consolidated Balance Sheets. Dominion Energy Gas’ borrowings under the IRCA with Dominion Energy totaled $18 million and $118 million as of December 31, 2017 and 2016, respectively. The weighted-average interest rate of these borrowings was 1.60% and 1.08% at December 31, 2017 and 2016, respectively. Interest charges related to Dominion Energy Gas’ total borrowings from Dominion Energy were immaterial for 2017, 2016 and 2015.

OPERATING SEGMENTS

OPERATING SEGMENTS	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
OPERATING SEGMENTS	N OTE PERATING EGMENTS The Companies are organized primarily on the basis of products and services sold in the U.S. A description of the operations included in the Companies’ primary operating segments is as follows: Primary Operating Description of Operations Dominion Virginia Dominion Power Delivery Regulated electric distribution X X Regulated electric transmission X X Power Generation Regulated electric fleet X X Merchant electric fleet X Gas Infrastructure Gas transmission and storage X (1) X Gas distribution and storage X X Gas gathering and processing X X LNG terminalling and storage X Nonregulated retail energy marketing X (1) Includes remaining producer services activities. In addition to the operating segments above, the Companies also report a Corporate and Other segment. D OMINION NERGY The Corporate and Other Segment of Dominion Energy In 2017, Dominion Energy reported an after-tax The net benefit for specific items in 2017 primarily related to the impact of the following items: • A $979 million tax benefit resulting from the remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act, primarily attributable to: • Gas Infrastructure ($324 million); • Power Generation ($655 million); partially offset by • $158 million ($96 million after-tax) In 2016, Dominion Energy reported after-tax The net expenses for specific items in 2016 primarily related to the impact of the following items: • A $197 million ($122 million after-tax) • A $59 million ($36 million after-tax) • Power Delivery ($5 million after-tax); • Gas Infrastructure ($12 million after-tax); • Power Generation ($19 million after-tax). In 2015, Dominion Energy reported after-tax The net expenses for specific items in 2015 primarily related to the impact of the following items: • A $99 million ($60 million after-tax) • An $85 million ($52 million after-tax) write-off The following table presents segment information pertaining to Dominion Energy’s operations: Year Ended December 31, Power Power Gas Corporate and Other Adjustments & Eliminations Consolidated Total (millions) 2017 Total revenue from external customers $2,206 $6,676 $2,832 $ 16 $ 856 $12,586 Intersegment revenue 22 10 834 610 (1,476 ) — Total operating revenue 2,228 6,686 3,666 626 (620 ) 12,586 Depreciation, depletion and amortization 593 747 522 43 — 1,905 Equity in earnings of equity method investees — (181) 159 4 — (18 ) Interest income 4 92 45 96 (155 ) 82 Interest and related charges 265 342 109 644 (155 ) 1,205 Income tax expense (benefit) 334 373 487 (1,224 ) — (30 ) Net income attributable to Dominion Energy 531 1,181 898 389 — 2,999 Investment in equity method investees — 81 1,422 41 — 1,544 Capital expenditures 1,433 2,275 2,149 52 — 5,909 Total assets (billions) 16.7 29.0 28.0 12.0 (9.1 ) 76.6 2016 Total revenue from external customers $2,210 $6,747 $2,069 $ (7 ) $ 718 $11,737 Intersegment revenue 23 10 697 609 (1,339 ) — Total operating revenue 2,233 6,757 2,766 602 (621 ) 11,737 Depreciation, depletion and amortization 537 662 330 30 — 1,559 Equity in earnings of equity method investees — (16) 105 22 — 111 Interest income — 74 34 36 (78 ) 66 Interest and related charges 244 290 38 516 (78 ) 1,010 Income tax expense (benefit) 308 279 431 (363 ) — 655 Net income (loss) attributable to Dominion Energy 484 1,397 726 (484 ) — 2,123 Investment in equity method investees — 228 1,289 44 — 1,561 Capital expenditures 1,320 2,440 2,322 43 — 6,125 Total assets (billions) 15.6 27.1 26.0 10.2 (7.3 ) 71.6 2015 Total revenue from external customers $2,091 $7,001 $1,877 $ (27) $ 741 $11,683 Intersegment revenue 20 15 695 554 (1,284 ) — Total operating revenue 2,111 7,016 2,572 527 (543 ) 11,683 Depreciation, depletion and amortization 498 591 262 44 — 1,395 Equity in earnings of equity method investees — (15 ) 60 11 — 56 Interest income — 64 25 13 (44 ) 58 Interest and related charges 230 262 27 429 (44 ) 904 Income tax expense (benefit) 307 465 423 (290 ) — 905 Net income (loss) attributable to Dominion Energy 490 1,120 680 (391 ) — 1,899 Investment in equity method investees — 245 1,042 33 — 1,320 Capital expenditures 1,607 2,190 2,153 43 — 5,993 Intersegment sales and transfers for Dominion Energy are based on contractual arrangements and may result in intersegment profit or loss that is eliminated in consolidation. V IRGINIA OWER The majority of Virginia Power’s revenue is provided through tariff rates. Generally, such revenue is allocated for management reporting based on an unbundled rate methodology among Virginia Power’s Power Delivery and Power Generation segments. The Corporate and Other Segment of Virginia Power In 2017, Virginia Power reported an after-tax The net benefit for specific items in 2017 primarily related to the impact of the following item: • A $93 million tax benefit resulting from the remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act, attributable to Power Generation. In 2016, Virginia Power reported after-tax The net expenses for specific items in 2016 primarily related to the impact of the following item: • A $197 million ($121 million after-tax) In 2015, Virginia Power reported after-tax The net expenses for specific items in 2015 primarily related to the impact of the following items: • A $99 million ($60 million after-tax) • An $85 million ($52 million after-tax) write-off The following table presents segment information pertaining to Virginia Power’s operations: Year Ended December 31, Power Power Corporate and Other Adjustments & Eliminations Consolidated Total (millions) 2017 Operating revenue $2,212 $5,344 $ — $ — $7,556 Depreciation and amortization 594 547 — — 1,141 Interest income 4 15 3 (3 ) 19 Interest and related charges 265 232 — (3 ) 494 Income tax expense (benefit) 334 534 (94 ) — 774 Net income 527 939 74 — 1,540 Capital expenditures 1,439 1,290 — — 2,729 Total assets (billions) 16.6 18.6 — (0.1 ) 35.1 2016 Operating revenue $2,217 $5,390 $ (19 ) $ — $7,588 Depreciation and amortization 537 488 — — 1,025 Interest income — — — — — Interest and related charges 244 219 — (2 ) 461 Income tax expense (benefit) 307 524 (104 ) — 727 Net income (loss) 482 909 (173 ) — 1,218 Capital expenditures 1,313 1,336 — — 2,649 Total assets (billions) 15.6 17.8 — (0.1 ) 33.3 2015 Operating revenue $2,099 $5,566 $ (43 ) $ — $7,622 Depreciation and amortization 498 453 2 — 953 Interest income — 7 — — 7 Interest and related charges 230 210 4 (1 ) 443 Income tax expense (benefit) 308 437 (86 ) — 659 Net income (loss) 490 750 (153 ) — 1,087 Capital expenditures 1,569 1,120 — — 2,689 D OMINION NERGY AS The Corporate and Other Segment of Dominion Energy Gas In 2017, Dominion Energy Gas reported after-tax The net benefit for specific items in 2017 primarily related to the impact of the following item: • A $185 million tax benefit resulting from the remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act. In 2016, Dominion Energy Gas reported after-tax The net expense for specific items in 2016 primarily related to the impact of the following item: • An $8 million ($5 million after-tax) In 2015, Dominion Energy Gas reported after-tax The net expenses for specific items in 2015 primarily related to the impact of the following item: • $16 million ($10 million after-tax) The following table presents segment information pertaining to Dominion Energy Gas’ operations: Year Ended December 31, Gas Infrastructure Corporate and Consolidated Total (millions) 2017 Operating revenue $1,814 $ — $1,814 Depreciation and amortization 227 — 227 Equity in earnings of equity method investees 21 — 21 Interest income 2 — 2 Interest and related charges 97 — 97 Income tax expense (benefit) 256 (205 ) 51 Net income 436 179 615 Investment in equity method investees 95 — 95 Capital expenditures 778 — 778 Total assets (billions) 11.3 0.6 11.9 2016 Operating revenue $1,638 $ — $1,638 Depreciation and amortization 214 (10 ) 204 Equity in earnings of equity method investees 21 — 21 Interest income 1 — 1 Interest and related charges 92 2 94 Income tax expense (benefit) 237 (22 ) 215 Net income (loss) 395 (3 ) 392 Investment in equity method investees 98 — 98 Capital expenditures 854 — 854 Total assets (billions) 10.5 0.6 11.1 2015 Operating revenue $1,716 $ — $1,716 Depreciation and amortization 213 4 217 Equity in earnings of equity method investees 23 — 23 Interest income 1 — 1 Interest and related charges 72 1 73 Income tax expense (benefit) 296 (13 ) 283 Net income (loss) 478 (21 ) 457 Investment in equity method investees 102 — 102 Capital expenditures 795 — 795

QUARTERLY FINANCIALAND COMMON S

QUARTERLY FINANCIALAND COMMON STOCKDATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY FINANCIALAND COMMON STOCKDATA (UNAUDITED)	N OTE UARTERLY INANCIAL AND OMMON TOCK ATA NAUDITED A summary of the Companies’ quarterly results of operations for the years ended December 31, 2017 and 2016 follows. Amounts reflect all adjustments necessary in the opinion of management for a fair statement of the results for the interim periods. Results for interim periods may fluctuate as a result of weather conditions, changes in rates and other factors. D OMINION NERGY First Quarter Second Quarter Third Quarter Fourth Quarter (millions, except per share amounts) 2017 Operating revenue $ 3,384 $ 2,813 $ 3,179 $ 3,210 Income from operations 1,079 753 1,152 953 Net income including noncontrolling interests 674 417 696 1,333 Net income attributable to Dominion Energy 632 390 665 1,312 Basic EPS: Net income attributable to Dominion Energy 1.01 0.62 1.03 2.04 Diluted EPS: Net income attributable to Dominion Energy 1.01 0.62 1.03 2.04 Dividends declared per share 0.755 0.755 0.770 0.770 Common stock prices (intraday high-low) $ 79.36 - 70.87 $ 81.65 - 76.17 $ 80.67 - 75.40 $ 85.30 - 75.75 2016 Operating revenue $ 2,921 $ 2,598 $ 3,132 $ 3,086 Income from operations 841 740 1,102 765 Net income including noncontrolling interests 531 462 728 491 Net income attributable to Dominion Energy 524 452 690 457 Basic EPS: Net income attributable to Dominion Energy 0.88 0.73 1.10 0.73 Diluted EPS: Net income attributable to Dominion Energy 0.88 0.73 1.10 0.73 Dividends declared per share 0.700 0.700 0.700 0.700 Common stock prices (intraday high-low) $ 75.18 - 66.25 $ 77.93 - 68.71 $ 78.97 - 72.49 $ 77.32 - 69.51 Dominion Energy’s 2017 results include the impact of the following significant item: • Fourth quarter results include $851 million tax benefit resulting from the remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act, partially offset by $96 million of after-tax Dominion Energy’s 2016 results include the impact of the following significant item: • Fourth quarter results include a $122 million after-tax V IRGINIA OWER Virginia Power’s quarterly results of operations were as follows: First Quarter Second Quarter Third Quarter Fourth Quarter (millions) 2017 Operating revenue $ 1,831 $ 1,747 $ 2,154 $ 1,824 Income from operations 653 613 847 619 Net income 356 318 459 407 2016 Operating revenue $ 1,890 $ 1,776 $ 2,211 $ 1,711 Income from operations 514 553 914 369 Net income 263 280 503 172 Virginia Power’s 2017 results include the impact of the following significant item: • Fourth quarter results include a $93 million tax benefit resulting from the remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act. Virginia Power’s 2016 results include the impact of the following significant item: • Fourth quarter results include a $121 million after-tax D OMINION NERGY AS Dominion Energy Gas’ quarterly results of operations were as follows: First Quarter Second Quarter Third Quarter Fourth Quarter (millions) 2017 Operating revenue $490 $422 $401 $501 Income from operations 156 116 185 182 Net income 108 77 117 313 2016 Operating revenue $431 $368 $382 $457 Income from operations 156 167 114 156 Net income 98 105 83 106 Dominion Energy Gas’s 2017 results include the impact of the following significant item: • Fourth quarter results include a $197 million tax benefit resulting from the remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act. There were no significant items impacting Dominion Energy Gas’ 2016 quarterly results.

Significant Accounting Polici35

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Estimates	The Companies make certain estimates and assumptions in preparing their Consolidated Financial Statements in accordance with GAAP. These estimates and assumptions affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues, expenses and cash flows for the periods presented. Actual results may differ from those estimates.
Consolidation	The Companies’ Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of their respective majority-owned subsidiaries and non-wholly-owned
Consolidation, consolidated entities and noncontrolling interest	For certain partnership structures, income is allocated based on the liquidation value of the underlying contractual arrangements. NRG’s ownership interest in Four Brothers and Three Cedars, as well as Terra Nova Renewable Partners’ 33% interest in certain of Dominion Energy’s merchant solar projects, is reflected as noncontrolling interest in Dominion Energy’s Consolidated Financial Statements. See Note 3 for further information on these transactions.
Reclassifications	Certain amounts in the Companies’ 2017, 2016 and 2015 Consolidated Financial Statements and Notes have been reclassified as a result of the adoption of revised accounting guidance pertaining to certain net periodic pension and other postretirement benefit costs, restricted cash and equivalents and certain distributions from equity method investees. In addition, certain other amounts in the 2016 and 2015 Consolidated Financial Statements and Notes have been reclassified to conform to the 2017 presentation for comparative purposes; however, such reclassifications did not affect the Companies’ net income, total assets, liabilities, equity or cash flows.
Operating Revenue	Operating Revenue Operating revenue is recorded on the basis of services rendered, commodities delivered or contracts settled and includes amounts yet to be billed to customers. Dominion Energy and Virginia Power collect sales, consumption and consumer utility taxes and Dominion Energy Gas collects sales taxes; however, these amounts are excluded from revenue. Dominion Energy’s customer receivables at December 31, 2017 and 2016 included $661 million and $631 million, respectively, of accrued unbilled revenue based on estimated amounts of electricity and natural gas delivered but not yet billed to its utility customers. Virginia Power’s customer receivables at December 31, 2017 and 2016 included $400 million and $349 million, respectively, of accrued unbilled revenue based on estimated amounts of electricity delivered but not yet billed to its customers. Dominion Energy Gas’ customer receivables at December 31, 2017 and 2016 included $121 million and $134 million, respectively, of accrued unbilled revenue based on estimated amounts of natural gas delivered but not yet billed to its customers. See Note 9 for amounts attributable to related parties. The primary types of sales and service activities reported as operating revenue for Dominion Energy are as follows: • Regulated electric sales • Nonregulated electric sales • Regulated gas sales • Nonregulated gas sales • Gas transportation and storage • Other revenue The primary types of sales and service activities reported as operating revenue for Virginia Power are as follows: • Regulated electric sales • Other revenue The primary types of sales and service activities reported as operating revenue for Dominion Energy Gas are as follows: • Regulated gas sales • Nonregulated gas sales • Gas transportation and storage • NGL revenue • Other revenue
Electric Fuel, Purchased Energy and Purchased Gas-Deferred Costs	Electric Fuel, Purchased Energy and Purchased Gas-Deferred Where permitted by regulatory authorities, the differences between Dominion Energy’s and Virginia Power’s actual electric fuel and purchased energy expenses and Dominion Energy’s and Dominion Energy Gas’ purchased gas expenses and the related levels of recovery for these expenses in current rates are deferred and matched against recoveries in future periods. The deferral of costs in excess of current period fuel rate recovery is recognized as a regulatory asset, while rate recovery in excess of current period fuel expenses is recognized as a regulatory liability. Of the cost of fuel used in electric generation and energy purchases to serve utility customers, approximately 84% is currently subject to deferred fuel accounting, while substantially all of the remaining amount is subject to recovery through similar mechanisms. Virtually all of Dominion Energy Gas’, Cove Point’s, Questar Gas’ and Hope’s natural gas purchases are either subject to deferral accounting or are recovered from the customer in the same accounting period as the sale.
Income Taxes	Income Taxes A consolidated federal income tax return is filed for Dominion Energy and its subsidiaries, including Virginia Power and Dominion Energy Gas’ subsidiaries. In addition, where applicable, combined income tax returns for Dominion Energy and its subsidiaries are filed in various states; otherwise, separate state income tax returns are filed. Although Dominion Energy Gas is disregarded for income tax purposes, a provision for income taxes is recognized to reflect the inclusion of its business activities in the tax returns of its parent, Dominion Energy. Virginia Power and Dominion Energy Gas participate in intercompany tax sharing agreements with Dominion Energy and its subsidiaries. Current income taxes are based on taxable income or loss and credits determined on a separate company basis. Under the agreements, if a subsidiary incurs a tax loss or earns a credit, recognition of current income tax benefits is limited to refunds of prior year taxes obtained by the carryback of the net operating loss or credit or to the extent the tax loss or credit is absorbed by the taxable income of other Dominion Energy consolidated group members. Otherwise, the net operating loss or credit is carried forward and is recognized as a deferred tax asset until realized. The 2017 Tax Reform Act includes a broad range of tax reform provisions affecting the Companies, including changes in corporate tax rates and business deductions. The 2017 Tax Reform Act reduces the corporate income tax rate from 35% to 21% for tax years beginning after December 31, 2017. Deferred tax assets and liabilities are classified as noncurrent in the Consolidated Balance Sheets and measured at the enacted tax rate expected to apply when temporary differences are realized or settled. Thus, at the date of enactment, federal deferred taxes were remeasured based upon the new 21% tax rate. The total effect of tax rate changes on deferred tax balances is recorded as a component of the income tax provision related to continuing operations for the period in which the law is enacted, even if the assets and liabilities relate to other components of the financial statements, such as items of accumulated other comprehensive income. For Dominion Energy subsidiaries that are not rate-regulated utilities, existing deferred income tax assets or liabilities were adjusted for the reduction in the corporate income tax rate and allocated to continuing operations. Dominion Energy’s rate-regulated utility subsidiaries likewise are required to adjust deferred income tax assets and liabilities for the change in income tax rates. However, if it is probable that the effect of the change in income tax rates will be recovered or refunded in future rates, the regulated utility recorded a regulatory asset or liability instead of an increase or decrease to deferred income tax expense. Accounting for income taxes involves an asset and liability approach. Deferred income tax assets and liabilities are provided, representing future effects on income taxes for temporary differences between the bases of assets and liabilities for financial reporting and tax purposes. Accordingly, deferred taxes are recognized for the future consequences of different treatments used for the reporting of transactions in financial accounting and income tax returns. The Companies establish a valuation allowance when it is more-likely-than-not The Companies recognize positions taken, or expected to be taken, in income tax returns that are more-likely-than-not If it is not more-likely-than-not The Companies recognize interest on underpayments and overpayments of income taxes in interest expense and other income, respectively. Penalties are also recognized in other income. Dominion Energy and Virginia Power both recognized interest income of $11 million in 2017. Dominion Energy Gas’ interest was immaterial in 2017. Interest for the Companies was immaterial in 2016 and 2015. Dominion Energy’s, Virginia Power’s and Dominion Energy Gas’ penalties were immaterial in 2017, 2016 and 2015. At December 31, 2017, Virginia Power had an income tax-related In addition, Virginia Power’s Consolidated Balance Sheet at December 31, 2017 included $1 million of noncurrent federal income taxes receivable, less than $1 million of state income taxes receivable and $1 million of noncurrent state income taxes receivable. Dominion Energy Gas’ Consolidated Balance Sheet at December 31, 2017 included $14 million of state income taxes receivable. At December 31, 2016, Virginia Power had an income tax-related In addition, Virginia Power’s Consolidated Balance Sheet at December 31, 2016 included $2 million of noncurrent federal income taxes payable, $6 million of state income taxes receivable and $13 million of noncurrent state income taxes receivable. Dominion Energy Gas’ Consolidated Balance Sheet at December 31, 2016 included $1 million of noncurrent federal income taxes payable, $1 million of state income taxes receivable and $7 million of noncurrent state income taxes payable. Investment tax credits are recognized by nonregulated operations in the year qualifying property is placed in service. For regulated operations, investment tax credits are deferred and amortized over the service lives of the properties giving rise to the credits. Production tax credits are recognized as energy is generated and sold.
Cash, Restricted Cash and Equivalents	Cash, Restricted Cash and Equivalents Current banking arrangements generally do not require checks to be funded until they are presented for payment. The following table illustrates the checks outstanding but not yet presented for payment and recorded in accounts payable for the Companies: Year Ended December 31, 2017 2016 (millions) Dominion Energy $ 30 $ 24 Virginia Power 17 11 Dominion Energy Gas 7 9 R ESTRICTED ASH AND QUIVALENTS The Companies hold restricted cash and equivalent balances that primarily consist of amounts held for certain customer deposits, future debt payments on SBL Holdco and Dominion Solar Projects III, Inc.’s term loan agreements and a distribution reserve at Cove Point. Upon adoption of revised accounting guidance in January 2018, restricted cash and equivalents are included within the Companies’ Consolidated Statements of Cash Flows, with the change in balance no longer considered a separate investing activity. The guidance required retrospective application which resulted in adjustments to other cash provided by (used in) investing activities presented within Dominion Energy, Virginia Power and Dominion Energy Gas’ Consolidated Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015, which were previously reported as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy $ 29 $ 47 $ (71 ) Virginia Power (51 ) (33 ) (87 ) Dominion Energy Gas (23 ) (18 ) (11 ) The following table provides a reconciliation of the total cash, restricted cash and equivalents reported within the Companies’ Consolidated Balance Sheets to the corresponding amounts reported within the Companies’ Consolidated Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015: Cash, Restricted Cash and Equivalents at At December 31, 2017 2016 2015 2014 (millions) Dominion Energy Cash and cash equivalents $ 120 $ 261 $ 607 $ 318 Restricted cash and equivalents (1) 65 61 25 19 Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 185 $ 322 $ 632 $ 337 Virginia Power Cash and cash equivalents $ 14 $ 11 $ 18 $ 15 Restricted cash and equivalents (1) 10 — — — Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 24 $ 11 $ 18 $ 15 Dominion Energy Gas Cash and cash equivalents $ 4 $ 23 $ 13 $ 9 Restricted cash and equivalents (1) 26 20 14 13 Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 30 $ 43 $ 27 $ 22 (1) Restricted cash and equivalent balances are presented within other current assets in the Companies’ Consolidated Balance Sheets. D ISTRIBUTIONS FROM QUITY ETHOD NVESTEES Dominion Energy and Dominion Energy Gas each hold investments that are accounted for under the equity method of accounting. Effective January 2018, Dominion Energy and Dominion Energy Gas classify distributions from equity method investees as either cash flows from operating activities or cash flows from investing activities in the Consolidated Statements of Cash Flows according to the nature of the distribution. Dis-tributions received are classified on the basis of the nature of the activity of the investee that generated the distribution as either a return on investment (classified as cash flows from operating activities) or a return of an investment (classified as cash flows from investing activities) when such information is available to Dominion Energy and Dominion Energy Gas. Previously, distributions were determined to be either a return on an investment or return of an investment based on a cumulative earnings approach whereby any distributions received in excess of earnings were considered to be a return of an investment. Dominion Energy and Dominion Energy Gas have applied this approach on a retrospective basis. As a result distributions from equity method investees were reclassified within the Consolidated Statements of Cash Flows between distributions from equity method affiliates and other cash used in investing activities at Dominion Energy and Dominion Energy Gas, respectively, to other adjustments from operating activities for both Dominion Energy and Dominion Energy Gas, which were previously reported as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy $ (37 ) $ (108 ) $ (42 ) Dominion Energy Gas (9 ) (6 ) 16 For purposes of the Consolidated Statements of Cash Flows, cash, restricted cash and equivalents include cash on hand, cash in banks and temporary investments purchased with an original maturity of three months or less.
Derivative Instruments	Derivative Instruments Dominion Energy uses derivative instruments such as physical and financial forwards, futures, swaps, options and FTRs to manage the commodity, interest rate and foreign currency exchange rate risks of its business operations. Virginia Power uses derivative instruments such as physical and financial forwards, futures, swaps, options and FTRs to manage commodity and interest rate risks. Dominion Energy Gas uses derivative instruments such as physical and financial forwards, futures and swaps to manage commodity, interest rate and foreign currency exchange rate risks. All derivatives, except those for which an exception applies, are required to be reported in the Consolidated Balance Sheets at fair value. Derivative contracts representing unrealized gain positions and purchased options are reported as derivative assets. Derivative contracts representing unrealized losses and options sold are reported as derivative liabilities. One of the exceptions to fair value accounting, normal purchases and normal sales, may be elected when the contract satisfies certain criteria, including a requirement that physical delivery of the underlying commodity is probable. Expenses and revenues resulting from deliveries under normal purchase contracts and normal sales contracts, respectively, are included in earnings at the time of contract performance. The Companies do not offset amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral against amounts recognized for derivative instruments executed with the same counterparty under the same master netting arrangement. Dominion Energy had margin assets of $92 million and $82 million associated with cash collateral at December 31, 2017 and 2016, respectively. Dominion Energy’s margin liabilities associated with cash collateral at December 31, 2017 or 2016 were immaterial. Virginia Power had margin assets of $23 million and $2 million associated with cash collateral at December 31, 2017 and 2016, respectively. Virginia Power’s margin liabilities associated with cash collateral were immaterial at December 31, 2017 and 2016. Dominion Energy Gas’ margin assets and liabilities associated with cash collateral were immaterial at December 31, 2017 and 2016. See Note 7 for further information about derivatives. To manage price risk, the Companies hold certain derivative instruments that are not designated as hedges for accounting purposes. However, to the extent the Companies do not hold offsetting positions for such derivatives, they believe these instruments represent economic hedges that mitigate their exposure to fluctuations in commodity prices. All income statement activity, including amounts realized upon settlement, is presented in operating revenue, operating expenses, interest and related charges or other income based on the nature of the underlying risk. Changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities for jurisdictions subject to cost-based rate regulation. Realized gains or losses on the derivative instruments are generally recognized when the related transactions impact earnings. D ERIVATIVE NSTRUMENTS ESIGNATED AS EDGING NSTRUMENTS The Companies designate a portion of their derivative instruments as either cash flow or fair value hedges for accounting purposes. For all derivatives designated as hedges, the Companies formally document the relationship between the hedging instrument and the hedged item, as well as the risk management objective and the strategy for using the hedging instrument. The Companies assess whether the hedging relationship between the derivative and the hedged item is highly effective at offsetting changes in cash flows or fair values both at the inception of the hedging relationship and on an ongoing basis. Any change in the fair value of the derivative that is not effective at offsetting changes in the cash flows or fair values of the hedged item is recognized currently in earnings. Also, the Companies may elect to exclude certain gains or losses on hedging instruments from the assessment of hedge effectiveness, such as gains or losses attributable to changes in the time value of options or changes in the difference between spot prices and forward prices, thus requiring that such changes be recorded currently in earnings. Hedge accounting is discontinued prospectively for derivatives that cease to be highly effective hedges. For derivative instruments that are accounted for as fair value hedges or cash flow hedges, the cash flows from the derivatives and from the related hedged items are classified in operating cash flows. Cash Flow Hedges Dominion Energy entered into interest rate derivative instruments to hedge its forecasted interest payments related to planned debt issuances in 2014. These interest rate derivatives were designated by Dominion Energy as cash flow hedges prior to the formation of Dominion Energy Gas. For the purposes of the Dominion Energy Gas financial statements, the derivative balances, AOCI balance, and any income statement impact related to these interest rate derivative instruments entered into by Dominion Energy have been, and will continue to be, included in the Dominion Energy Gas’ Consolidated Financial Statements as the forecasted interest payments related to the debt issuances now occur at Dominion Energy Gas. Fair Value Hedges
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment is recorded at lower of original cost or fair value, if impaired. Capitalized costs include labor, materials and other direct and indirect costs such as asset retirement costs, capitalized interest and, for certain operations subject to cost-of-service In 2017, 2016 and 2015, Dominion Energy capitalized interest costs and AFUDC to property, plant and equipment of $236 million, $159 million and $100 million, respectively. In 2017, 2016 and 2015, Virginia Power capitalized AFUDC to property, plant and equipment of $37 million, $21 million and $30 million, respectively. In 2017, 2016 and 2015, Dominion Energy Gas capitalized AFUDC to property, plant and equipment of $25 million, $8 million and $1 million, respectively. Under Virginia law, certain Virginia jurisdictional projects qualify for current recovery of AFUDC through rate adjustment clauses. AFUDC on these projects is calculated and recorded as a regulatory asset and is not capitalized to property, plant and equipment. In 2017, 2016 and 2015, Virginia Power recorded $22 million, $31 million and $19 million of AFUDC related to these projects, respectively. For property subject to cost-of-service cost-of-service plant-in-service For property that is not subject to cost-of-service Depreciation of property, plant and equipment is computed on the straight-line method based on projected service lives. The Companies’ average composite depreciation rates on utility property, plant and equipment are as follows: Year Ended December 31, 2017 2016 2015 (percent) Dominion Energy Generation 2.94 2.83 2.78 Transmission 2.55 2.47 2.42 Distribution 3.00 3.02 3.11 Storage 2.48 2.29 2.42 Gas gathering and processing 2.21 2.66 3.19 General and other 4.89 4.12 3.67 Virginia Power Generation 2.94 2.83 2.78 Transmission 2.54 2.36 2.33 Distribution 3.32 3.32 3.33 General and other 4.68 3.49 3.40 Dominion Energy Gas Transmission 2.40 2.43 2.46 Distribution 2.42 2.55 2.45 Storage 2.45 2.19 2.44 Gas gathering and processing 2.42 2.58 3.20 General and other 4.96 4.54 4.72 In the first quarter of 2017, Virginia Power revised the depreciation rates for its assets to reflect the results of a new depreciation study. This change resulted in an increase in annual depreciation expense of $40 million ($25 million after-tax) after-tax) Capitalized costs of development wells and leaseholds are amortized on a field-by-field unit-of-production Dominion Energy’s nonutility property, plant and equipment is depreciated using the straight-line method over the following estimated useful lives: Asset Estimated Useful Lives Merchant generation-nuclear 44 years Merchant generation-other 15-40 years Nonutility gas gathering and processing 3-50 General and other 5-59 Depreciation and amortization related to Virginia Power’s and Dominion Energy Gas’ nonutility property, plant and equipment and exploration and production properties was immaterial for the years ended December 31, 2017, 2016 and 2015, except for Dominion Energy Gas’ nonutility gas gathering and processing properties which are depreciated using the straight-line method over estimated useful lives between 10 and 50 years. Nuclear fuel used in electric generation is amortized over its estimated service life on a units-of-production
Long-Lived and Intangible Assets	Long-Lived and Intangible Assets The Companies perform an evaluation for impairment whenever events or changes in circumstances indicate that the carrying amount of long-lived assets or intangible assets with finite lives may not be recoverable. A long-lived or intangible asset is written down to fair value if the sum of its expected future undiscounted cash flows is less than its carrying amount. Intangible assets with finite lives are amortized over their estimated useful lives.
Regulatory Assets and Liabilities	Regulatory Assets and Liabilities The accounting for Dominion Energy’s and Dominion Energy Gas’ regulated gas and Virginia Power’s regulated electric operations differs from the accounting for nonregulated operations in that they are required to reflect the effect of rate regulation in their Consolidated Financial Statements. For regulated businesses subject to federal or state cost-of-service The Companies evaluate whether or not recovery of their regulatory assets through future rates is probable and make various assumptions in their analyses. The expectations of future recovery are generally based on orders issued by regulatory commissions, legislation or historical experience, as well as discussions with applicable regulatory authorities and legal counsel. If recovery of a regulatory asset is determined to be less than probable, it will be written off in the period such assessment is made.
Asset Retirement Obligations	Asset Retirement Obligations The Companies recognize AROs at fair value as incurred or when sufficient information becomes available to determine a reasonable estimate of the fair value of future retirement activities to be performed, for which a legal obligation exists. These amounts are generally capitalized as costs of the related tangible long-lived assets. Since relevant market information is not available, fair value is estimated using discounted cash flow analyses. Quarterly, the Companies assess their AROs to determine if circumstances indicate that estimates of the amounts or timing of future cash flows associated with retirement activities have changed. AROs are adjusted when significant changes in the amounts or timing of future cash flows are identified. Dominion Energy and Dominion Energy Gas report accretion of AROs and depreciation on asset retirement costs associated with their natural gas pipeline and storage well assets as an adjustment to the related regulatory liabilities when revenue is recoverable from customers for AROs. Virginia Power reports accretion of AROs and depreciation on asset retirement costs associated with decommissioning its nuclear power stations as an adjustment to the regulatory liability for certain jurisdictions. Additionally, Virginia Power reports accretion of AROs and depreciation on asset retirement costs associated with certain rider and prospective rider projects as an adjustment to the regulatory asset for certain jurisdictions. Accretion of all other AROs and depreciation of all other asset retirement costs are reported in other operations and maintenance expense and depreciation expense, respectively, in the Consolidated Statements of Income.
Debt Issuance Costs	Debt Issuance Costs The Companies defer and amortize debt issuance costs and debt premiums or discounts over the expected lives of the respective debt issues, considering maturity dates and, if applicable, redemption rights held by others. Deferred debt issuance costs are recorded as a reduction in long-term debt in the Consolidated Balance Sheets. Amortization of the issuance costs is reported as interest expense. Unamortized costs associated with redemptions of debt securities prior to stated maturity dates are generally recognized and recorded in interest expense immediately. As permitted by regulatory authorities, gains or losses resulting from the refinancing of debt allocable to utility operations subject to cost-based rate regulation are deferred and amortized over the lives of the new issuances.
Investments	Investments M ARKETABLE QUITY AND EBT ECURITIES Dominion Energy accounts for and classifies investments in marketable equity and debt securities as trading or available-for-sale available-for-sale • Trading securities • Available-for-sale available-for-sale after-tax. In determining realized gains and losses for marketable equity and debt securities, the cost basis of the security is based on the specific identification method. N ON -M ARKETABLE NVESTMENTS The Companies account for illiquid and privately held securities for which market prices or quotations are not readily available under either the equity or cost method. Non-marketable • Equity method investments • Cost method investments O THER HAN EMPORARY MPAIRMENT The Companies periodically review their investments to determine whether a decline in fair value should be considered other-than-temporary. If a decline in fair value of any security is determined to be other-than-temporary, the security is written down to its fair value at the end of the reporting period. Decommissioning Trust Investments—Special Considerations • The recognition provisions of the FASB’s other-than-temporary impairment guidance apply only to debt securities classified as available-for-sale held-to-maturity, • Debt Securities more-likely-than-not non-performance • Equity securities and other investments day-to-day non-marketable
Inventories	Inventories Materials and supplies and fossil fuel inventories are valued primarily using the weighted-average cost method. Stored gas inventory is valued using the weighted-average cost method, except for East Ohio gas distribution operations, which are valued using the LIFO method. Under the LIFO method, current stored gas inventory was valued at $9 million and $13 million at December 31, 2017 and December 31, 2016, respectively. Based on the average price of gas purchased during 2017 and 2016, the cost of replacing the current portion of stored gas inventory exceeded the amount stated on a LIFO basis by $79 million and $55 million, respectively.
Gas Imbalances	Gas Imbalances Natural gas imbalances occur when the physical amount of natural gas delivered from, or received by, a pipeline system or storage facility differs from the contractual amount of natural gas delivered or received. Dominion Energy and Dominion Energy Gas value these imbalances due to, or from, shippers and operators at an appropriate index price at period end, subject to the terms of its tariff for regulated entities. Imbalances are primarily settled in-kind.
Goodwill	Goodwill Dominion Energy and Dominion Energy Gas evaluate goodwill for impairment annually as of April 1 and whenever an event occurs or circumstances change in the interim that would more-likely-than-not
New Accounting Standards	New Accounting Standards R EVENUE ECOGNITION In May 2014, the FASB issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this revised accounting guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consid-eration to which the entity expects to be entitled in exchange for those goods or services. The amendments in this update also require disclosure of the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. For the Companies, the revised accounting guidance is effective for interim and annual periods beginning January 1, 2018. The Companies have completed their evaluations of the impact of this guidance and expect no significant impact on their results of operations. However, the Companies will have offsetting increases in operating revenues and other energy-related purchases for noncash consideration related to NGLs received in consideration for performing processing and fractionation services and offsetting decreases in operating revenues and purchased gas for fuel retained to offset costs on certain transportation and storage arrangements. The Companies will apply the standard using the modified retrospective method as opposed to the full retrospective method. F INANCIAL NSTRUMENTS In January 2016, the FASB issued revised accounting guidance for the recognition, measurement, presentation and disclosure of financial instruments. In accordance with the guidance effective January 2018, Dominion Energy and Virginia Power will no longer classify equity securities as trading or available-for-sale Upon adoption of this guidance for equity securities held at January 1, 2018, Dominion Energy and Virginia Power recorded the cumulative-effect of a change in accounting principle to reclassify net unrealized gains from AOCI to retained earnings and to recognize equity securities previously categorized as cost method investments at fair value in nuclear decommissioning trust funds in the Consolidated Balance Sheets and a cumulative-effect adjustment to retained earnings. Dominion Energy and Virginia Power reclassified approximately $1.1 billion ($734 million after-tax) after-tax) after-tax), L EASES In February 2016, the FASB issued revised accounting guidance for the recognition, measurement, presentation and disclosure of leasing arrangements. The update requires that a liability and corresponding right-of-use The guidance is effective for the Companies’ interim and annual reporting periods beginning January 1, 2019, although it can be early adopted, with a modified retrospective approach, which requires lessees and lessors to recognize and measure leases at the beginning of the earliest period presented for leases that commenced prior to the date of adoption. The Companies plan to elect the proposed transition expedient which would allow the Companies to maintain historical presentation for periods before January 1, 2019. The Companies expect to elect the other practical expedients, which would require no reassessment of whether existing contracts are or contain leases and no reassessment of lease classification for existing leases. The Companies have completed a preliminary assessment for evaluating the impact of this guidance and anticipate that its adoption will result in a significant amount of offsetting right-of-use on-going D EFINITION OF A USINESS In January 2017, the FASB issued revised accounting guidance to clarify the definition of a business. The revised guidance affects the evaluation of whether a transaction should be accounted for as an acquisition or disposition of an asset or a business, which may impact goodwill and related financial statement disclosures. The Companies have adopted this guidance on a prospective basis effective October 1, 2017. The adoption of the pronouncement will result in additional transactions being accounted for as asset acquisitions or dispositions. D ERECOGNITION AND ARTIAL ALES OF ONFINANCIAL SSETS In February 2017, the FASB issued revised accounting guidance clarifying the scope of asset derecognition guidance and accounting for partial sales of nonfinancial assets. The guidance is effective for the Companies’ interim and annual reporting periods beginning January 1, 2018, and the Companies have elected to apply the standard using the modified retrospective method. Upon adoption of the standard on January 1, 2018, Dominion Energy recorded the cumulative-effect of a change in accounting principle to reclassify $127 million from noncontrolling interests to common stock related to the sale of a noncontrolling interest in certain merchant solar projects completed in December 2015 and January 2016. N ET ERIODIC ENSION AND THER OSTRETIREMENT ENEFIT OSTS In March 2017, the FASB issued revised accounting guidance for the presentation of net periodic pension and other postretirement benefit costs. The update requires that the service cost component of net periodic pension and other postretirement benefit costs be classified in the same line item as other compensation costs arising from services rendered by employees, while all other components of net periodic pension and other postretirement costs are classified outside of income from operations. In addition, only the service cost component remains eligible for capitalization during construction. These changes do not impact the accounting by participants in a multi-employer plan. The standard also recognizes that in the event that a regulator continues to require capitalization of all net periodic benefit costs prospectively, the difference would result in recognition of a regulatory asset or liability. For costs not capitalized for which regulators are expected to provide recovery, a regulatory asset will be established. As such, the amounts eligible for capitalization in the Consolidated Financial Statements of Virginia Power and Dominion Energy Gas, as subsidiary participants in Dominion Energy’s multi-employer plans, will differ from the amounts eligible for capitalization in the Consolidated Financial Statements of Dominion Energy, the plan administrator. These differences will result in a regulatory asset or liability recorded in the Consolidated Financial Statements of Dominion Energy. This guidance became effective for the Companies beginning January 1, 2018 with a retrospective adoption for income statement presentation and a prospective adoption for capitalization. Dominion Energy’s and Dominion Energy Gas’ Consolidated Statements of Income for the years ended December 31, 2017, 2016 and 2015 have been recast to reflect retrospective adoption for the presentation of the non-service cost component of net periodic pension and other postretirement benefit costs. Previously, the non-service cost component for Dominion Energy and Dominion Energy Gas was reflected in other operations and maintenance in the Consolidated Statements of Income, along with the service cost component of net periodic pension and other postretirement benefit costs. Subsequent to the adoption of this guidance, the non-service cost component of net periodic pension and other postretirement benefit costs is recorded in other income in the Consolidated Statements of Income. As previously reported, Dominion Energy and Dominion Energy Gas’ other operations and maintenance expense and other income were as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy Other operations and maintenance expense $ 2,875 $ 3,064 $ 2,595 Other income 165 250 196 Dominion Energy Gas Other operations and maintenance expense 440 393 326 Other income 20 11 1 T AX EFORM In December 2017, the staff of the SEC issued guidance which clarifies accounting for income taxes if information is not yet available or complete and provides for up to a one-year measurement period in which to complete the required analyses and accounting. The guidance describes three scenarios associated with a company’s status of accounting for income tax reform: (1) a company is complete with its accounting for certain effects of tax reform, (2) a company is able to determine a reasonable estimate for certain effects of tax reform and records that estimate as a provisional amount, or (3) a company is not able to determine a reasonable estimate and therefore continues to apply accounting for income taxes based on the provisions of the tax laws that were in effect immediately prior to the 2017 Tax Reform Act being enacted. In addition, the guidance provides clarification related to disclosures for entities which are utilizing the measurement period. The Companies have recorded their best estimate of the impacts of the 2017 Tax Reform Act as discussed above and in Note 5. The amounts are considered to be provisional and may result in adjustments to be recognized during the measurement period. In February 2018, the FASB issued revised accounting guidance to provide clarification on the application of the 2017 Tax Reform Act for balances recorded within AOCI. The revised guidance provides for stranded amounts within AOCI from the impacts of the 2017 Tax Reform Act to be reclassified to retained earnings. The guidance is effective for the Companies’ interim and annual reporting periods beginning January 1, 2019, with early adoption permitted, and may be applied prospectively or retrospectively upon adoption. If the Companies had adopted this guidance for the period ended December 31, 2017, Dominion Energy would have reclassified a benefit of $165 million from AOCI to retained earnings, Dominion Energy Gas would have reclassified a benefit of $26 million from AOCI to membership interests and Virginia Power would have reclassified an expense of $13 million from AOCI to retained earnings.
Fair Value Measurements	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (exit price) in an orderly transaction between market participants at the measurement date. However, the use of a mid-market mid-point Inputs and Assumptions The Companies maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Fair value is based on actively-quoted market prices, if available. In the absence of actively-quoted market prices, price information is sought from external sources, including broker quotes and industry publications. When evaluating pricing information provided by brokers and other pricing services, the Companies consider whether the broker is willing and able to trade at the quoted price, if the broker quotes are based on an active market or an inactive market and the extent to which brokers are utilizing a particular model if pricing is not readily available. If pricing information from external sources is not available, or if the Companies believe that observable pricing is not indicative of fair value, judgment is required to develop the estimates of fair value. In those cases the Companies must estimate prices based on available historical and near-term future price information and certain statistical methods, including regression analysis, that reflect their market assumptions. The Companies’ commodity derivative valuations are prepared by Dominion Energy’s ERM department. The ERM department creates daily mark-to-market mark-to-market mark-to-market mark-to-market For options and contracts with option-like characteristics where observable pricing information is not available from external sources, Dominion Energy and Virginia Power generally use a modified Black-Scholes Model that considers time value, the volatility of the underlying commodities and other relevant assumptions when estimating fair value. Dominion Energy and Virginia Power use other option models under special circumstances, including a Spread Approximation Model when contracts include different commodities or commodity locations and a Swing Option Model when contracts allow either the buyer or seller the ability to exercise within a range of quantities. For contracts with unique characteristics, the Companies may estimate fair value using a discounted cash flow approach deemed appropriate in the circumstances and applied consistently from period to period. For individual contracts, the use of different valuation models or assumptions could have a significant effect on the contract’s estimated fair value. The inputs and assumptions used in measuring fair value include the following: For commodity derivative contracts: • Forward commodity prices • Transaction prices • Price volatility • Price correlation • Volumes • Commodity location • Interest rates • Credit quality of counterparties and the Companies • Credit enhancements • Time value For interest rate derivative contracts: • Interest rate curves • Credit quality of counterparties and the Companies • Notional value • Credit enhancements • Time value For foreign currency derivative contracts: • Foreign currency forward exchange rates • Interest rates • Credit quality of counterparties and the Companies • Notional value • Credit enhancements • Time value For investments: • Quoted securities prices and indices • Securities trading information including volume and restrictions • Maturity • Interest rates • Credit quality The Companies regularly evaluate and validate the inputs used to estimate fair value by a number of methods, including review and verification of models, as well as various market price verification procedures such as the use of pricing services and multiple broker quotes to support the market price of the various commodities and investments in which the Companies transact. Levels The Companies also utilize the following fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: • Level 1—Quoted prices (unadjusted) in active markets for identical assets and liabilities that they have the ability to access at the measurement date. Instruments categorized in Level 1 primarily consist of financial instruments such as certain exchange-traded derivatives, and exchange-listed equities, U.S. and international equity securities, mutual funds and certain Treasury securities held in nuclear decommissioning trust funds for Dominion Energy and Virginia Power, benefit plan trust funds for Dominion Energy and Dominion Energy Gas, and rabbi trust funds for Dominion Energy. • Level 2—Inputs other than quoted prices included within Level 1 that are either directly or indirectly observable for the asset or liability, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability, and inputs that are derived from observable market data by correlation or other means. Instruments categorized in Level 2 primarily include commodity forwards and swaps, interest rate swaps, foreign currency swaps and cash and cash equivalents, corporate debt instruments, government securities and other fixed income investments held in nuclear decommissioning trust funds for Dominion Energy and Virginia Power, benefit plan trust funds for Dominion Energy and Dominion Energy Gas and rabbi trust funds for Dominion Energy. • Level 3—Unobservable inputs for the asset or liability, including situations where there is little, if any, market activity for the asset or liability. Instruments categorized in Level 3 for the Companies consist of long-dated commodity derivatives, FTRs, certain natural gas and power options and other modeled commodity derivatives. The fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1) and the lowest priority to unobservable data (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. In these cases, the lowest level input that is significant to a fair value measurement in its entirety determines the applicable level in the fair value hierarchy. Assessing the significance of a particular input to the fair value measurement in its entirety requires judgment, considering factors specific to the asset or liability. Alternative investments, consisting of investments in partnerships, joint ventures and other alternative investments held in nuclear decommissioning and benefit plan trust funds, are generally valued using NAV based on the proportionate share of the fair value as determined by reference to the most recent audited fair value financial statements or fair value statements provided by the investment manager adjusted for any significant events occurring between the investment manager’s and the Companies’ measurement date. Alternative investments recorded at NAV are not classified in the fair value hierarchy. For derivative contracts, the Companies recognize transfers among Level 1, Level 2 and Level 3 based on fair values as of the first day of the month in which the transfer occurs. Transfers out of Level 3 represent assets and liabilities that were previously classified as Level 3 for which the inputs became observable for classification in either Level 1 or Level 2. Because the activity and liquidity of commodity markets vary substantially between regions and time periods, the availability of observable inputs for substantially the full term and value of the Companies’ over-the-counter Level 3 Valuations Fair value measurements are categorized as Level 3 when price or other inputs that are considered to be unobservable are significant to their valuations. Long-dated commodity derivatives are generally based on unobservable inputs due to the length of time to settlement and the absence of market activity and are therefore categorized as Level 3. FTRs are categorized as Level 3 fair value measurements because the only relevant pricing available comes from ISO auctions, which are generally not considered to be liquid markets. Other modeled commodity derivatives have unobservable inputs in their valuation, mostly due to non-transparent The Companies enter into certain physical and financial forwards, futures, options and swaps, which are considered Level 3 as they have one or more inputs that are not observable and are significant to the valuation. The discounted cash flow method is used to value Level 3 physical and financial forwards and futures contracts. An option model is used to value Level 3 physical and financial options. The discounted cash flow model for forwards and futures calculates mark-to-market mark-to-market
Regulatory Matters Involving Potential Loss Contingencies	Regulatory Matters Involving Potential Loss Contingencies As a result of issues generated in the ordinary course of business, the Companies are involved in various regulatory matters. Certain regulatory matters may ultimately result in a loss; however, as such matters are in an initial procedural phase, involve uncertainty as to the outcome of pending reviews or orders, and/or involve significant factual issues that need to be resolved, it is not possible for the Companies to estimate a range of possible loss. For matters for which the Companies cannot estimate a range of possible loss, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the regulatory process such that the Companies are able to estimate a range of possible loss. For regulatory matters for which the Companies are able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any estimated range is based on currently available information, involves elements of judgment and significant uncertainties and may not represent the Companies’ maximum possible loss exposure. The circumstances of such regulatory matters will change from time to time and actual results may vary significantly from the current estimate. For current matters not specifically reported below, management does not anticipate that the outcome from such matters would have a material effect on the Companies’ financial position, liquidity or results of operations.
Employee Benefit Plans	Dominion Energy and Dominion Energy Gas—Defined Benefit Plans Dominion Energy provides certain retirement benefits to eligible active employees, retirees and qualifying dependents. Dominion Energy Gas participates in a number of the Dominion Energy-sponsored retirement plans. Under the terms of its benefit plans, Dominion Energy reserves the right to change, modify or terminate the plans. From time to time in the past, benefits have changed, and some of these changes have reduced benefits. Dominion Energy maintains qualified noncontributory defined benefit pension plans covering virtually all employees. Retirement benefits are based primarily on years of service, age and the employee’s compensation. Dominion Energy’s funding policy is to contribute annually an amount that is in accordance with the provisions of ERISA. The pension programs also provide benefits to certain retired executives under company-sponsored nonqualified employee benefit plans. The nonqualified plans are funded through contributions to grantor trusts. Dominion Energy also provides retiree healthcare and life insurance benefits with annual employee premiums based on several factors such as age, retirement date and years of service. Pension benefits for Dominion Energy Gas employees not represented by collective bargaining units are covered by the Dominion Energy Pension Plan, a defined benefit pension plan sponsored by Dominion Energy that provides benefits to multiple Dominion Energy subsidiaries. Pension benefits for Dominion Energy Gas employees represented by collective bargaining units are covered by separate pension plans for East Ohio and, for DETI, a plan that provides benefits to employees of both DETI and Hope. Employee compensation is the basis for allocating pension costs and obligations between DETI and Hope and determining East Ohio’s share of total pension costs. Retiree healthcare and life insurance benefits for Dominion Energy Gas employees not represented by collective bargaining units are covered by the Dominion Retiree Health and Welfare Plan, a plan sponsored by Dominion Energy that provides certain retiree healthcare and life insurance benefits to multiple Dominion Energy subsidiaries. Retiree healthcare and life insurance benefits for Dominion Energy Gas employees represented by collective bargaining units are covered by separate other postretirement benefit plans for East Ohio and, for DETI, a plan that provides benefits to both DETI and Hope. Employee headcount is the basis for allocating other postretirement benefit costs and obligations between DETI and Hope and determining East Ohio’s share of total other postretirement benefit costs. Pension and other postretirement benefit costs are affected by employee demographics (including age, compensation levels and years of service), the level of contributions made to the plans and earnings on plan assets. These costs may also be affected by changes in key assumptions, including expected long-term rates of return on plan assets, discount rates, healthcare cost trend rates, mortality rates and the rate of compensation increases. Dominion Energy uses December 31 as the measurement date for all of its employee benefit plans, including those in which Dominion Energy Gas participates. Dominion Energy uses the market-related value of pension plan assets to determine the expected return on plan assets, a component of net periodic pension cost, for all pension plans, including those in which Dominion Energy Gas participates. The market-related value recognizes changes in fair value on a straight-line basis over a four-year period, which reduces year-to-year P LAN SSETS Dominion Energy’s overall objective for investing its pension and other postretirement plan assets is to achieve appropriate long-term rates of return commensurate with prudent levels of risk. As a participating employer in various pension plans sponsored by Dominion Energy, Dominion Energy Gas is subject to Dominion Energy’s investment policies for such plans. To minimize risk, funds are broadly diversified among asset classes, investment strategies and investment advisors. The strategic target asset allocations for Dominion Energy’s pension funds are 28% U.S. equity, 18% non-U.S. large-cap, mid-cap small-cap Non-U.S. large-cap small-cap non-U.S. Dominion Energy also utilizes common/collective trust funds as an investment vehicle for its defined benefit plans. A common/collective trust fund is a pooled fund operated by a bank or trust company for investment of the assets of various organizations and individuals in a well-diversified portfolio. Common/collective trust funds are funds of grouped assets that follow various investment strategies. Strategic investment policies are established for Dominion Energy’s prefunded benefit plans based upon periodic asset/liability studies. Factors considered in setting the investment policy include employee demographics, liability growth rates, future discount rates, the funded status of the plans and the expected long-term rate of return on plan assets. Deviations from the plans’ strategic allocation are a function of Dominion Energy’s assessments regarding short-term risk and reward opportunities in the capital markets and/or short-term market movements which result in the plans’ actual asset allocations varying from the strategic target asset allocations. Through periodic rebalancing, actual allocations are brought back in line with the target. Future asset/liability studies will focus on strategies to further reduce pension and other postretirement plan risk, while still achieving attractive levels of returns. Financial derivatives may be used to obtain or manage market exposures and to hedge assets and liabilities. The expected long-term rates of return on plan assets, discount rates, healthcare cost trend rates and mortality are critical assumptions in determining net periodic benefit (credit) cost. Dominion Energy develops non-investment Dominion Energy determines the expected long-term rates of return on plan assets for its pension plans and other postretirement benefit plans, including those in which Dominion Energy Gas participates, by using a combination of: • Expected inflation and risk-free interest rate assumptions; • Historical return analysis to determine long term historic returns as well as historic risk premiums for various asset classes; • Expected future risk premiums, asset volatilities and correlations; • Forward-looking return expectations derived from the yield on long-term bonds and the expected long-term returns of major stock market indices; and • Investment allocation of plan assets. Dominion Energy determines discount rates from analyses of AA/Aa rated bonds with cash flows matching the expected payments to be made under its plans, including those in which Dominion Energy Gas participates.
Commitments and Contingencies	As a result of issues generated in the ordinary course of business, the Companies are involved in legal proceedings before various courts and are periodically subject to governmental examinations (including by regulatory authorities), inquiries and investigations. Certain legal proceedings and governmental examinations involve demands for unspecified amounts of damages, are in an initial procedural phase, involve uncertainty as to the outcome of pending appeals or motions, or involve significant factual issues that need to be resolved, such that it is not possible for the Companies to estimate a range of possible loss. For such matters for which the Companies cannot estimate a range of possible loss, a statement to this effect is made in the description of the matter. Other matters may have progressed sufficiently through the litigation or investigative processes such that the Companies are able to estimate a range of possible loss. For legal proceedings and governmental examinations for which the Companies are able to reasonably estimate a range of possible losses, an estimated range of possible loss is provided, in excess of the accrued liability (if any) for such matters. Any accrued liability is recorded on a gross basis with a receivable also recorded for any probable insurance recoveries. Estimated ranges of loss are inclusive of legal fees and net of any anticipated insurance recoveries. Any estimated range is based on currently available information and involves elements of judgment and significant uncertainties. Any estimated range of possible loss may not represent the Companies’ maximum possible loss exposure. The circumstances of such legal proceedings and governmental examinations will change from time to time and actual results may vary significantly from the current estimate. For current proceedings not specifically reported below, management does not anticipate that the liabilities, if any, arising from such proceedings would have a material effect on the financial position, liquidity or results of operations of the Companies.
Guarantees, Surety Bonds and Letters of Credit	Dominion Energy also enters into guarantee arrangements on behalf of its consolidated subsidiaries, primarily to facilitate their commercial transactions with third parties. If any of these subsidiaries fail to perform or pay under the contracts and the counterparties seek performance or payment, Dominion Energy would be obligated to satisfy such obligation. To the extent that a liability subject to a guarantee has been incurred by one of Dominion Energy’s consolidated subsidiaries, that liability is included in the Consolidated Financial Statements. Dominion Energy is not required to recognize liabilities for guarantees issued on behalf of its subsidiaries unless it becomes probable that it will have to perform under the guarantees. Terms of the guarantees typically end once obligations have been paid. Dominion Energy currently believes it is unlikely that it would be required to perform or otherwise incur any losses associated with guarantees of its subsidiaries’ obligations.
Indemnifications	Indemnifications As part of commercial contract negotiations in the normal course of business, the Companies may sometimes agree to make payments to compensate or indemnify other parties for possible future unfavorable financial consequences resulting from specified events. The specified events may involve an adverse judgment in a lawsuit or the imposition of additional taxes due to a change in tax law or interpretation of the tax law. The Companies are unable to develop an estimate of the maximum potential amount of any other future payments under these contracts because events that would obligate them have not yet occurred or, if any such event has occurred, they have not been notified of its occurrence. However, at December 31, 2017, the Companies believe any other future payments, if any, that could ultimately become payable under these contract provisions, would not have a material impact on their results of operations, cash flows or financial position.
Credit Risk	Credit risk is the risk of financial loss if counterparties fail to perform their contractual obligations. In order to minimize overall credit risk, credit policies are maintained, including the evaluation of counterparty financial condition, collateral requirements and the use of standardized agreements that facilitate the netting of cash flows associated with a single counterparty. In addition, counterparties may make available collateral, including letters of credit or cash held as margin deposits, as a result of exceeding agreed-upon credit limits, or may be required to prepay the transaction. The Companies maintain a provision for credit losses based on factors surrounding the credit risk of their customers, historical trends and other information. Management believes, based on credit policies and the December 31, 2017 provision for credit losses, that it is unlikely that a material adverse effect on financial position, results of operations or cash flows would occur as a result of counterparty nonperformance.

Significant Accounting Polici36

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Checks Outstanding but Not Yet Presented for Payment	The following table illustrates the checks outstanding but not yet presented for payment and recorded in accounts payable for the Companies: Year Ended December 31, 2017 2016 (millions) Dominion Energy $ 30 $ 24 Virginia Power 17 11 Dominion Energy Gas 7 9
Other Cash Provided By (Used In) Investing Activities	The guidance required retrospective application which resulted in adjustments to other cash provided by (used in) investing activities presented within Dominion Energy, Virginia Power and Dominion Energy Gas’ Consolidated Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015, which were previously reported as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy $ 29 $ 47 $ (71 ) Virginia Power (51 ) (33 ) (87 ) Dominion Energy Gas (23 ) (18 ) (11 )
Reconciliation of Total Cash, Restricted Cash and Equivalents	The following table provides a reconciliation of the total cash, restricted cash and equivalents reported within the Companies’ Consolidated Balance Sheets to the corresponding amounts reported within the Companies’ Consolidated Statements of Cash Flows for the years ended December 31, 2017, 2016 and 2015: Cash, Restricted Cash and Equivalents at At December 31, 2017 2016 2015 2014 (millions) Dominion Energy Cash and cash equivalents $ 120 $ 261 $ 607 $ 318 Restricted cash and equivalents (1) 65 61 25 19 Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 185 $ 322 $ 632 $ 337 Virginia Power Cash and cash equivalents $ 14 $ 11 $ 18 $ 15 Restricted cash and equivalents (1) 10 — — — Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 24 $ 11 $ 18 $ 15 Dominion Energy Gas Cash and cash equivalents $ 4 $ 23 $ 13 $ 9 Restricted cash and equivalents (1) 26 20 14 13 Cash, restricted cash and equivalents shown in the Consolidated Statements of Cash Flows $ 30 $ 43 $ 27 $ 22 (1) Restricted cash and equivalent balances are presented within other current assets in the Companies’ Consolidated Balance Sheets.
Other Adjustments from Operating Activities	As a result distributions from equity method investees were reclassified within the Consolidated Statements of Cash Flows between distributions from equity method affiliates and other cash used in investing activities at Dominion Energy and Dominion Energy Gas, respectively, to other adjustments from operating activities for both Dominion Energy and Dominion Energy Gas, which were previously reported as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy $ (37 ) $ (108 ) $ (42 ) Dominion Energy Gas (9 ) (6 ) 16
Schedule of Depreciation Rates	The Companies’ average composite depreciation rates on utility property, plant and equipment are as follows: Year Ended December 31, 2017 2016 2015 (percent) Dominion Energy Generation 2.94 2.83 2.78 Transmission 2.55 2.47 2.42 Distribution 3.00 3.02 3.11 Storage 2.48 2.29 2.42 Gas gathering and processing 2.21 2.66 3.19 General and other 4.89 4.12 3.67 Virginia Power Generation 2.94 2.83 2.78 Transmission 2.54 2.36 2.33 Distribution 3.32 3.32 3.33 General and other 4.68 3.49 3.40 Dominion Energy Gas Transmission 2.40 2.43 2.46 Distribution 2.42 2.55 2.45 Storage 2.45 2.19 2.44 Gas gathering and processing 2.42 2.58 3.20 General and other 4.96 4.54 4.72
Property, Plant and Equipment	Dominion Energy’s nonutility property, plant and equipment is depreciated using the straight-line method over the following estimated useful lives: Asset Estimated Useful Lives Merchant generation-nuclear 44 years Merchant generation-other 15-40 years Nonutility gas gathering and processing 3-50 General and other 5-59
Other Operations and Maintenance Expense and Other Income	As previously reported, Dominion Energy and Dominion Energy Gas’ other operations and maintenance expense and other income were as follows: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy Other operations and maintenance expense $ 2,875 $ 3,064 $ 2,595 Other income 165 250 196 Dominion Energy Gas Other operations and maintenance expense 440 393 326 Other income 20 11 1

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Business Acquisitions, by Acquisition	The following table presents significant completed acquisitions of wholly-owned merchant solar projects by Dominion Energy. Completed Acquisition Seller Number of Project Project Name(s) Initial (1) Project (2) Date of Commercial MW April 2015 EC&R NA Solar PV, LLC 1 California Alamo $ 66 $ 66 May 2015 20 April 2015 EDF Renewable Development, Inc. 3 California Cottonwood (3) 106 106 May 2015 24 June 2015 EDF Renewable Development, Inc. 1 California Catalina 2 68 68 July 2015 18 July 2015 SunPeak Solar, LLC 1 California Imperial Valley 2 42 71 August 2015 20 November 2015 EC&R NA Solar PV, LLC 1 California Maricopa West 65 65 December 2015 20 November 2015 Community Energy Solar, LLC 1 Virginia Amazon Solar Farm 34 212 October 2016 80 February 2017 Community Energy Solar, LLC 1 Virginia Amazon Solar Farm 29 205 December 2017 100 March 2017 Solar Frontier Americas Holding LLC 1 (4) California Midway II 77 78 June 2017 30 May 2017 Cypress Creek Renewables, LLC 1 North IS37 154 160 June 2017 79 June 2017 Hecate Energy Virginia C&C LLC 1 Virginia Clarke County 16 16 August 2017 10 June 2017 Strata Solar Development, LLC/Moorings Farm 2 Holdco, LLC 2 North Fremont, Moorings 2 20 20 November 2017 10 September 2017 Hecate Energy Virginia C&C LLC 1 Virginia Cherrydale 40 41 November 2017 20 October 2017 Strata Solar Development, LLC 2 North Clipperton, Pikeville 20 21 November 2017 10 (1) The purchase price was primarily allocated to Property, Plant and Equipment. (2) Includes acquisition cost. (3) One of the projects, Marin Carport, began commercial operations in 2016. (4) In April 2017, Dominion Energy discontinued efforts on the acquisition of the additional 20 MW solar project from Solar Frontier Americas Holding LLC.
Dominion Energy Questar Corporation
Schedule of Preliminary Allocation of Purchase Price to Assets Acquired and Liabilities Assumed	The table below shows the allocation of the purchase price to the assets acquired and liabilities assumed at closing which reflects the following adjustments from the preliminary valuation recog-nized during the measurement period. During the fourth quarter of 2016, certain modifications were made to preliminary valuation amounts for acquired property, plant and equipment, current liabilities, and deferred income taxes, resulting in a $6 million net decrease to goodwill, which related primarily to the sale of Questar Fueling Company in December 2016 as further described in the Sale of Questar Fueling Company Amount (millions) Total current assets $ 224 Investments (1) 58 Property, plant and equipment (2) 4,131 Goodwill 3,111 Total deferred charges and other assets, excluding goodwill 75 Total Assets 7,599 Total current liabilities (3) 793 Long-term debt (4) 963 Deferred income taxes 807 Regulatory liabilities 259 Asset retirement obligations 160 Other deferred credits and other liabilities 220 Total Liabilities 3,202 Total purchase price 4,397 (1) Includes $40 million for an equity method investment in White River Hub. The fair value adjustment on the equity method investment in White River Hub is considered to be equity method goodwill and is not amortized. (2) Nonregulated property, plant and equipment, excluding land, will be depreciated over remaining useful lives primarily ranging from 9 to 18 years. (3) Includes $301 million of short-term debt, of which no amounts remain outstanding at December 31, 2017, as well as a $250 million variable interest rate term loan due in August 2017 that was paid in July 2017. (4) Unsecured senior and medium-term notes with maturities which range from 2017 to 2048 and bear interest at rates from 2.98% to 7.20%.
Business Acquisition, Pro Forma Information	The following unaudited pro forma financial information reflects the consolidated results of operations of Dominion Energy assuming the Dominion Energy Questar Combination had taken place on January 1, 2015. The unaudited pro forma financial information has been presented for illustrative purposes only and is not necessarily indicative of the consolidated results of operations that would have been achieved or the future consolidated results of operations of the combined company. Twelve Months Ended December 31, 2016 (1) 2015 (millions, except EPS) Operating Revenue $12,497 $12,818 Net income attributable to Dominion Energy 2,300 2,108 Earnings Per Common Share – Basic $ 3.73 $ 3.56 Earnings Per Common Share – Diluted $ 3.73 $ 3.55 (1) Amounts include adjustments for non-recurring

Operating Revenue (Tables)

Operating Revenue (Tables)	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Operating Revenue	The Companies’ operating revenue consists of the following: Year Ended December 31, 2017 2016 2015 (millions) Dominion Energy Electric sales: Regulated $ 7,383 $ 7,348 $ 7,482 Nonregulated 1,429 1,519 1,488 Gas sales: Regulated 1,067 500 218 Nonregulated 457 354 471 Gas transportation and storage 1,786 1,636 1,616 Other 464 380 408 Total operating revenue $ 12,586 $ 11,737 $ 11,683 Virginia Power Regulated electric sales $ 7,383 $ 7,348 $ 7,482 Other 173 240 140 Total operating revenue $ 7,556 $ 7,588 $ 7,622 Dominion Energy Gas Gas sales: Regulated $ 87 $ 119 $ 122 Nonregulated 20 13 10 Gas transportation and storage 1,435 1,307 1,366 NGL revenue 91 62 93 Other 181 137 125 Total operating revenue $ 1,814 $ 1,638 $ 1,716

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense for continuing operations including noncontrolling interests	Details of income tax expense for continuing operations including noncontrolling interests were as follows: Dominion Energy Virginia Power Dominion Energy Gas Year Ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 (millions) Current: Federal $ (1 ) $ (155 ) $ (24 ) $ 432 $ 168 $ 316 $ 16 $ (27 ) $ 90 State (26 ) 85 75 73 90 92 8 4 30 Total current expense (benefit) (27 ) (70 ) 51 505 258 408 24 (23 ) 120 Deferred: Federal 2017 Tax Reform Act impact (851 ) — — (93 ) — — (197 ) — — Taxes before operating loss carryforwards and investment tax credits 739 1,050 384 319 435 154 199 239 156 Tax utilization expense (benefit) of operating loss carryforwards 174 (161 ) 539 4 (2 ) 96 5 (2 ) 6 Investment tax credits (200 ) (248 ) (134 ) (23 ) (25 ) (11 ) — — — State 132 50 66 59 27 13 20 1 1 Total deferred expense (benefit) (6 ) 691 855 266 435 252 27 238 163 Investment tax credit-gross deferral 5 35 — 5 35 — — — — Investment tax credit-amortization (2 ) (1 ) (1 ) (2 ) (1 ) (1 ) — — — Total income tax expense (benefit) $ (30 ) $ 655 $ 905 $ 774 $ 727 $ 659 $ 51 $ 215 $ 283
Effective Income Tax	For continuing operations including noncontrolling interests, the statutory U.S. federal income tax rate reconciles to the Companies’ effective income tax rate as follows: Dominion Energy Virginia Power Dominion Energy Gas Year Ended December 31, 2017 2016 2015 2017 2016 2015 2017 2016 2015 U.S. statutory rate 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % 35.0 % Increases (reductions) resulting from: State taxes, net of federal benefit 2.0 2.4 3.7 3.7 3.8 3.9 2.4 0.5 2.7 Investment tax credits (6.3 ) (11.7 ) (4.7 ) (0.8 ) — (0.6 ) — — — Production tax credits (0.7 ) (0.8 ) (0.8 ) (0.4 ) (0.5 ) (0.6 ) — — — Valuation allowances 0.2 1.2 (0.3 ) — 0.1 — 0.3 — — Federal legislative change (27.5 ) — — (4.0 ) — — (29.5 ) — — State legislative change — (0.6 ) (0.1 ) — — — — — — AFUDC—equity (1.4 ) (0.6 ) (0.3 ) (0.6 ) (0.6 ) (0.6 ) (0.9 ) (0.2 ) 0.2 Employee stock ownership plan deduction (0.6 ) (0.6 ) (0.6 ) — — — — — — Other, net (1.7 ) (1.4 ) 0.1 0.6 (0.4 ) 0.6 0.4 0.1 0.3 Effective tax rate (1.0 )% 22.9 % 32.0 % 33.5 % 37.4 % 37.7 % 7.7 % 35.4 % 38.2 %
Deferred income taxes components	The Companies’ deferred income taxes consist of the following: Dominion Energy Virginia Power Dominion Energy At December 31, 2017 2016 2017 2016 2017 2016 (millions) Deferred income taxes: Total deferred income tax assets $ 2,686 $ 1,827 $ 923 $ 268 $ 320 $ 126 Total deferred income tax liabilities 7,158 10,381 3,600 5,323 1,774 2,564 Total net deferred income tax liabilities $ 4,472 $ 8,554 $ 2,677 $5,055 $1,454 $ 2,438 Total deferred income taxes: Plant and equipment, primarily depreciation method and basis differences $ 5,056 $ 7,782 $ 2,969 $4,604 $1,132 $ 1,726 Excess deferred income taxes (1,050 ) — (687 ) — (244 ) — Nuclear decommissioning 829 1,240 260 406 — — Deferred state income taxes 834 747 378 321 227 204 Federal benefit of deferred state income taxes (175 ) (261 ) (79 ) (112 ) (48 ) (71 ) Deferred fuel, purchased energy and gas costs 1 (25 ) (3 ) (29 ) 2 4 Pension benefits 141 155 (104 ) (138 ) 419 646 Other postretirement benefits (51 ) (68 ) 44 49 (2 ) (6 ) Loss and credit carryforwards (1,536 ) (1,547 ) (111 ) (88 ) (4 ) (5 ) Valuation allowances 146 135 5 3 3 — Partnership basis differences 473 688 — — 26 43 Other (196 ) (292 ) 5 39 (57 ) (103 ) Total net deferred income tax liabilities $ 4,472 $ 8,554 $ 2,677 $5,055 $1,454 $ 2,438 Deferred Investment Tax Credits – Regulated Operations 51 48 51 48 — — Total Deferred Taxes and Deferred Investment Tax Credits $ 4,523 $ 8,602 $ 2,728 $5,103 $1,454 $ 2,438
Summary of deductible loss and credit carryforwards	At December 31, 2017, Dominion Energy had the following deductible loss and credit carryforwards: Deductible Amount Deferred Tax Asset Valuation Expiration Period (millions) Federal losses $ 560 $ 118 $ — 2034 Federal investment credits — 938 — 2033-2037 Federal production credits — 129 — 2031-2037 Other federal credits — 58 — 2031-2037 State losses 1,366 103 (63 ) 2018-2037 State minimum tax credits — 90 — No expiration State investment and other credits — 100 (83 ) 2018-2027 Total $1,926 $1,536 $(146 ) At December 31, 2017, Virginia Power had the following deductible loss and credit carryforwards: Deductible Amount Deferred Tax Asset Valuation Allowance Expiration (millions) Federal losses $ 1 $ — $— 2034 Federal investment credits — 51 — 2034-2037 Federal production and other credits — 51 — 2031-2037 State investment credits — 9 (5 ) 2024 Total $ 1 $111 $(5 ) At December 31, 2017, Dominion Energy Gas had the following deductible loss and credit carryforwards: Deductible Amount Deferred Tax Asset Valuation Allowance Expiration Period (millions) Other federal credits $ — $1 $ 2032-2036 State losses 33 3 (3 ) 2036-2037 Total $33 $4 $ )
Reconciliation of changes in unrecognized tax benefits	A reconciliation of changes in the Companies’ unrecognized tax benefits follows: Dominion Energy Virginia Power Dominion Energy Gas 2017 2016 2015 2017 2016 2015 2017 2016 2015 (millions) Balance at January 1 $ 64 $ 103 $ 145 $ 13 $ 12 $ 36 $ 7 $ 29 $29 Increases-prior period positions 1 9 2 — 4 — — 1 — Decreases-prior period positions (9 ) (44 ) (40 ) (1 ) (3 ) (25 ) — (19 ) — Increases-current period positions 5 6 8 — — 1 — — — Settlements with tax authorities (23 ) (8 ) (5 ) (8 ) — — (7 ) (4 ) — Expiration of statutes of limitations — (2 ) (7 ) — — — — — — Balance at December 31 $ 38 $ 64 $ 103 $ 4 $ 13 $ 12 $— $ 7 $29
Earliest tax year remaining	For each of the major states in which Dominion Energy operates, the earliest tax year remaining open for examination is as follows: State Earliest Open Tax Year Pennsylvania (1) 2012 Connecticut 2014 Virginia (2) 2014 West Virginia (1) 2014 New York (1) 2011 Utah 2014 (1) Considered a major state for Dominion Energy Gas’ operations. (2) Considered a major state for Virginia Power’s operations.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Inputs, Assets, Quantitative Information	The following table presents Dominion Energy’s quantitative information about Level 3 fair value measurements at December 31, 2017. The range and weighted average are presented in dollars for market price inputs and percentages for price volatility. Fair Value (millions) Valuation Techniques Unobservable Input Range Weighted Average (1) Assets Physical and financial forwards and futures: Natural gas (2) $ 84 Discounted cash flow Market price (per Dth) (4) (2) - 14 — FTRs 29 Discounted cash flow Market price (per MWh) (4) (1) - 7 2 Physical options: Natural gas 1 Option model Market price (per Dth) (4) 2 - 7 3 Price volatility (5) 26% - 54% 33 % Electricity 43 Option model Market price (per MWh) (4) 22 - 74 37 Price volatility (5) 13% - 63% 33 % Total assets $157 Liabilities Financial forwards: Liquids (3) $ 2 Discounted cash flow Market price (per Gal) (4) 0 - 2 1 FTRs $ 5 Discounted cash flow Market price (per MWh) (4) (4) - 6 — Total liabilities $ 7 (1) Averages weighted by volume. (2) Includes basis. (3) Includes NGLs and oil. (4) Represents market prices beyond defined terms for Levels 1 and 2. (5) Represents volatilities unrepresented in published markets.
Fair Value, Option, Qualitative Disclosures	Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows: Significant Unobservable Inputs Position Change to Input Impact on Fair Value Measurement Market price Buy Increase (decrease) Gain (loss) Market price Sell Increase (decrease) Loss (gain) Price volatility Buy Increase (decrease) Gain (loss) Price volatility Sell Increase (decrease) Loss (gain)
Fair Value, by Balance Sheet Grouping	The following table presents Dominion Energy’s assets and liabilities that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions: Level 1 Level 2 Level 3 Total (millions) December 31, 2017 Assets Derivatives: Commodity $ — $ 101 $157 $ 258 Interest rate — 17 — 17 Foreign currency — 32 — 32 Investments (1) Equity securities: U.S. 3,493 — — 3,493 Fixed income: Corporate debt instruments — 444 — 444 Government securities 307 794 — 1,101 Cash equivalents and other 34 — — 34 Total assets $ 3,834 $ 1,388 $157 $ 5,379 Liabilities Derivatives: Commodity $ — $ 190 $ 7 $ 197 Interest rate — 85 — 85 Foreign currency — 2 — 2 Total liabilities $ — $ 277 $ 7 $ 284 December 31, 2016 Assets Derivatives: Commodity $ — $ 115 $147 $ 262 Interest rate — 17 — 17 Investments (1) Equity securities: U.S. 2,913 — — 2,913 Fixed income: Corporate debt instruments — 487 — 487 Government securities 424 614 — 1,038 Cash equivalents and other 5 — — 5 Total assets $ 3,342 $ 1,233 $147 $ 4,722 Liabilities Derivatives: Commodity $ — $ 88 $ 8 $ 96 Interest rate — 53 — 53 Foreign currency — 6 — 6 Total liabilities $ — $ 147 $ 8 $ 155 (1) Includes investments held in the nuclear decommissioning and rabbi trusts. Excludes $88 million and $89 million of assets at December 31, 2017 and 2016, respectively, measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy.
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents the net change in Dominion Energy’s assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category: 2017 2016 2015 (millions) Balance at January 1, $ 139 $ 95 $ 107 Total realized and unrealized gains (losses): Included in earnings (38 ) (35 ) (5 ) Included in other comprehensive loss (2 ) — (9 ) Included in regulatory assets/liabilities 42 (39 ) (4 ) Settlements 6 38 9 Purchases — 87 — Transfers out of Level 3 3 (7 ) (3 ) Balance at December 31, $ 150 $ 139 $ 95 The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets still held at the reporting date $ 2 $ (1 ) $ 2
Fair Value Unobservable Inputs Gain (Loss) Included In Earnings	The following table presents Dominion Energy’s gains and losses included in earnings in the Level 3 fair value category: Operating Revenue Electric Fuel and Other Energy-Related Purchases Purchased Gas Total (millions) Year Ended December 31, 2017 Total gains (losses) included in earnings $ 3 $(42 ) $ 1 $ (38 ) The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date 2 — — 2 Year Ended December 31, 2016 Total gains (losses) included in earnings $— $(35 ) $— $ (35 ) The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date — (1 ) — (1 ) Year Ended December 31, 2015 Total gains (losses) included in earnings $ 6 $(11 ) $— $ (5 ) The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date 1 1 — 2
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	For the Companies’ financial instruments that are not recorded at fair value, the carrying amounts and estimated fair values are as follows: December 31, 2017 2016 Carrying Amount Estimated Fair Value (1) Carrying Amount Estimated Fair Value (1) (millions) Dominion Energy Long-term debt, including securities due within one year (2) $ 28,666 $31,233 $ 26,587 $28,273 Junior subordinated notes (3) 3,981 4,102 2,980 2,893 Remarketable subordinated notes (3) 1,379 1,446 2,373 2,418 Virginia Power Long-term debt, including securities due within one year (3) $ 11,346 $12,842 $ 10,530 $11,584 Dominion Energy Gas Long-term debt, including securities due within one year (4) $ 3,570 $ 3,719 $ 3,528 $ 3,603 (1) Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issues with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value. (2) Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium, and foreign currency remeasurement adjustments. At December 31, 2017, and 2016, includes the valuation of certain fair value hedges associated with Dominion Energy’s fixed rate debt of $(22) million and $(1) million, respectively. (3) Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium. (4) Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium, and foreign currency remeasurement adjustments.
Virginia Electric and Power Company
Fair Value Inputs, Assets, Quantitative Information	The following table presents Virginia Power’s quantitative information about Level 3 fair value measurements at December 31, 2017. The range and weighted average are presented in dollars for market price inputs and percentages for price volatility. Fair Value (millions) Valuation Techniques Unobservable Input Range Weighted Average (1) Assets Physical and financial forwards and futures: Natural gas (2) $ 81 Discounted cash flow Market price (per Dth) (3) (2)-7 (1 ) FTRs 27 Discounted cash flow Market price (per MWh) (3) (1)-7 2 Physical options: Natural gas 1 Option model Market price (per Dth) (3) 2-7 3 Price volatility (4) 26%-54% 33 % Electricity 43 Option model Market price (per MWh) (3) 22-74 37 Price volatility (4) 13%-63% 33 % Total assets $152 Liabilities: Financial forwards: FTRs $ 5 Discounted cash flow Market price (per MWh) (3) (4)-6 — Total liabilities $ 5 (1) Averages weighted by volume. (2) Includes basis. (3) Represents market prices beyond defined terms for Levels 1 and 2. (4) Represents volatilities unrepresented in published markets.
Fair Value, Option, Qualitative Disclosures	Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows: Significant Unobservable Position Change to Input Impact on Fair Value Measurement Market price Buy Increase (decrease) Gain (loss) Market price Sell Increase (decrease) Loss (gain) Price volatility Buy Increase (decrease) Gain (loss) Price volatility Sell Increase (decrease) Loss (gain)
Fair Value, by Balance Sheet Grouping	The following table presents Virginia Power’s assets and liabilities that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions: Level 1 Level 2 Level 3 Total (millions) December 31, 2017 Assets Derivatives: Commodity $ — $ 14 $ 152 $ 166 Investments (1) Equity securities: U.S. 1,566 — — 1,566 Fixed income: Corporate debt instruments — 224 — 224 Government securities 168 326 — 494 Cash equivalents and other 16 — — 16 Total assets $ 1,750 $ 564 $ 152 $ 2,466 Liabilities Derivatives: Commodity $ — $ 4 $ 5 $ 9 Interest rate — 57 — 57 Total liabilities $ — $ 61 $ 5 $ 66 December 31, 2016 Assets Derivatives: Commodity $ — $ 43 $ 145 $ 188 Interest rate — 6 — 6 Investments (1) Equity securities: U.S. 1,302 — — 1,302 Fixed income: Corporate debt instruments — 277 — 277 Government securities 136 291 — 427 Total assets $ 1,438 $ 617 $ 145 $ 2,200 Liabilities Derivatives: Commodity $ — $ 8 $ 2 $ 10 Interest rate — 21 — 21 Total liabilities $ — $ 29 $ 2 $ 31 (1) Includes investments held in the nuclear decommissioning trusts. Excludes $27 million and $26 million of assets at December 31, 2017 and 2016, respectively, measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy.
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents the net change in Virginia Power’s assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category: 2017 2016 2015 (millions) Balance at January 1, $ 143 $ 93 $ 102 Total realized and unrealized gains (losses): Included in earnings (43 ) (35 ) (13 ) Included in regulatory assets/liabilities 40 (37 ) (5 ) Settlements 7 35 13 Purchases — 87 — Transfers out of Level 3 — — (4 ) Balance at December 31, $ 147 $ 143 $ 93
Dominion Energy Gas Holdings, LLC
Fair Value Inputs, Assets, Quantitative Information	The following table presents Dominion Energy Gas’ quantitative information about Level 3 fair value measurements at December 31, 2017. The range and weighted average are presented in dollars for market price inputs. Fair Value (millions) Valuation Unobservable Range Weighted Average (1) Liabilities: Financial forwards: NGLs $2 Discounted Market (2) 0 - 1 1 Total liabilities $2 (1) Averages weighted by volume. (2) Represents market prices beyond defined terms for Levels 1 and 2.
Fair Value, Option, Qualitative Disclosures	Sensitivity of the fair value measurements to changes in the significant unobservable inputs is as follows: Significant Unobservable Inputs Position Change to Input Impact on Measurement Market price Buy Increase (decrease) Gain (loss) Market price Sell Increase (decrease) Loss (gain)
Fair Value, by Balance Sheet Grouping	The following table presents Dominion Energy Gas’ assets and liabilities for commodity and foreign currency derivatives that are measured at fair value on a recurring basis for each hierarchy level, including both current and noncurrent portions: Level 1 Level 2 Level 3 Total (millions) December 31, 2017 Assets Foreign currency $ — $32 $ $ 32 Total assets $ — $32 $ $ 32 Liabilities Commodity $ — $ 4 $ 2 $ 6 Foreign currency — 2 — 2 Total liabilities $ — $ 6 $ 2 $ 8 December 31, 2016 Liabilities Commodity $ — $ 3 $ 2 $ 5 Foreign currency — 6 — 6 Total liabilities $ — $ 9 $ 2 $ 11
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents the net change in Dominion Energy Gas’ derivative assets and liabilities measured at fair value on a recurring basis and included in the Level 3 fair value category: 2017 2016 2015 (millions) Balance at January 1, $ (2 ) $ 6 $ 2 Total realized and unrealized gains (losses): Included in earnings — — 1 Included in other comprehensive loss (3 ) — (5 ) Settlements — — (1 ) Transfers out of Level 3 3 (8 ) 9 Balance at December 31, $ (2 ) $ (2 ) $ 6

Derivatives and Hedge Account41

Derivatives and Hedge Accounting Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Offsetting Assets	The tables below present Dominion Energy’s derivative asset and liability balances by type of financial instrument, before and after the effects of offsetting: December 31, 2017 December 31, 2016 Gross Amounts of Assets Gross Amounts Offset in the Net Amounts of Presented in the Gross Amounts of Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Assets Presented in the Balance Sheet (millions) Commodity contracts: Over-the-counter $174 $— $174 $211 $— $211 Exchange 80 — 80 44 — 44 Interest rate contracts: Over-the-counter 17 — 17 17 — 17 Foreign currency contracts: Over-the-counter 32 — 32 — — — Total derivatives, subject to a master netting or similar arrangement 303 — 303 272 — 272 Total derivatives, not subject to a master netting or similar arrangement 4 — 4 7 — 7 Total $307 $— $307 $279 $— $279 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Net Amounts of Assets Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Received Net Amounts Net Amounts of Assets Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Received Net Amounts (millions) Commodity contracts: Over-the-counter $174 $ 9 $— $165 $211 $14 $— $197 Exchange 80 80 — — 44 44 — — Interest rate contracts: Over-the-counter 17 8 — 9 17 9 — 8 Foreign currency contracts: Over-the-counter 32 2 — 30 — — — — Total $303 $99 $— $204 $272 $67 $— $205
Offsetting Liabilities	December 31, 2017 December 31, 2016 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $ 76 $— $ 76 $ 23 $— $ 23 Exchange 120 — 120 71 — 71 Interest rate contracts: Over-the-counter 85 — 85 53 — 53 Foreign currency contracts: Over-the-counter 2 — 2 6 — 6 Total derivatives, subject to a master netting or similar arrangement 283 — 283 153 — 153 Total derivatives, not subject to a master netting or similar arrangement 1 — 1 2 — 2 Total $284 $— $284 $155 $— $155 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Paid Net Amounts Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Paid Net Amounts (millions) Commodity contracts: Over-the-counter $ 76 $ 9 $ 6 $ 61 $ 23 $14 $— $ 9 Exchange 120 80 40 — 71 44 27 — Interest rate contracts: Over-the-counter 85 8 — 77 53 9 — 44 Foreign currency contracts: Over-the-counter 2 2 — — 6 — — 6 Total $283 $99 $46 $138 $153 $67 $27 $59
Schedule of Volume of Derivative Activity	The following table presents the volume of Dominion Energy’s derivative activity as of December 31, 2017. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions, except in the case of offsetting transactions, for which they represent the absolute value of the net volume of their long and short positions. Current Noncurrent Natural Gas (bcf): Fixed price (1) 77 19 Basis 163 600 Electricity (MWh): Fixed price 10,552,363 364,990 FTRs 46,494,865 — Liquids (Gal) (2) 44,153,704 10,087,200 Interest rate (3) $ 1,950,000,000 $ 4,192,517,177 Foreign currency (3)(4) $ — $ 280,000,000 (1) Includes options. (2) Includes NGLs and oil. (3) Maturity is determined based on final settlement period. (4) Euro equivalent volumes are € 250,000,000.
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table presents selected information related to gains (losses) on cash flow hedges included in AOCI in Dominion Energy’s Consolidated Balance Sheet at December 31, 2017: AOCI After-Tax Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax Maximum Term (millions) Commodities: Gas $ (2 ) $ (3 ) 34 months Electricity (55 ) (55 ) 12 months Other (4 ) (4 ) 15 months Interest rate (246 ) (10 ) 384 months Foreign currency 5 (1 ) 102 months Total $(302 ) $(73 )
Fair Value of Derivatives	The following tables present the fair values of Dominion Energy’s derivatives and where they are presented in its Consolidated Balance Sheets: Fair Value – Derivatives Hedge Accounting Fair Value – Derivatives Hedge Accounting Total (millions) At December 31, 2017 ASSETS Current Assets Commodity $ 5 $158 $ 163 Interest rate 6 — 6 Total current derivative assets (1) 11 158 169 Noncurrent Assets Commodity — 95 95 Interest rate 11 — 11 Foreign currency 32 — 32 Total noncurrent derivative assets (2) 43 95 138 Total derivative assets $ 54 $253 $ 307 LIABILITIES Current Liabilities Commodity $103 $ 92 $ 195 Interest rate 53 — 53 Foreign currency 2 — 2 Total current derivative liabilities (3) 158 92 250 Noncurrent Liabilities Commodity 1 1 2 Interest rate 32 — 32 Total noncurrent derivative liabilities (4) 33 1 34 Total derivative liabilities $191 $ 93 $ 284 At December 31, 2016 ASSETS Current Assets Commodity $ 29 $101 $ 130 Interest rate 10 — 10 Total current derivative assets (1) 39 101 140 Noncurrent Assets Commodity — 132 132 Interest rate 7 — 7 Total noncurrent derivative assets (2) 7 132 139 Total derivative assets $ 46 $233 $ 279 LIABILITIES Current Liabilities Commodity $ 51 $ 41 $ 92 Interest rate 33 — 33 Foreign currency 3 — 3 Total current derivative liabilities (3) 87 41 128 Noncurrent Liabilities Commodity 1 3 4 Interest rate 20 — 20 Foreign currency 3 — 3 Total noncurrent derivative liabilities (4) 24 3 27 Total derivative liabilities $111 $ 44 $ 155 (1) Current derivative assets are presented in other current assets in Dominion Energy’s Consolidated Balance Sheets. (2) Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy’s Consolidated Balance Sheets. (3) Current derivative liabilities are presented in other current liabilities in Dominion Energy’s Consolidated Balance Sheets. (4) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy’s Consolidated Balance Sheets.
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following table presents the gains and losses on Dominion Energy’s derivatives, as well as where the associated activity is presented in its Consolidated Balance Sheets and Statements of Income: Derivatives in cash flow hedging relationships Amount of in AOCI on Derivatives Portion) (1) Amount of From AOCI Increase (Decrease) in Derivatives Subject to Regulatory (2) (millions) Year Ended December 31, 2017 Derivative type and location of gains (losses): Commodity: Operating revenue $ 81 Purchased gas (2 ) Total commodity $ 1 $ 79 $ — Interest rate (3) (8 ) (52 ) (58 ) Foreign currency (4) 18 20 — Total $ 11 $ 47 $(58 ) Year Ended December 31, 2016 Derivative type and location of gains (losses): Commodity: Operating revenue $330 Purchased gas (13 ) Electric fuel and other energy-related purchases (10 ) Total commodity $164 $307 $ — Interest rate (3) (66 ) (31 ) (26 ) Foreign currency (4) (6 ) (17 ) — Total $ 92 $259 $(26 ) Year Ended December 31, 2015 Derivative type and location of gains (losses): Commodity: Operating revenue $203 Purchased gas (15 ) Electric fuel and other energy-related purchases (1 ) Total commodity $230 $187 $ 4 Interest rate (3) (46 ) (11 ) (13 ) Total $184 $176 $ (9 ) (1) Amounts deferred into AOCI have no associated effect in Dominion Energy’s Consolidated Statements of Income. (2) Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion Energy’s Consolidated Statements of Income. (3) Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in interest and related charges. (4) Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in other income.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance	Derivatives not designated as hedging instruments Amount of Gain (Loss) Recognized in Income on Derivatives (1) Year Ended December 31, 2017 2016 2015 (millions) Derivative type and location of gains (losses): Commodity: Operating revenue $ 18 $ 2 $ 24 Purchased gas (3 ) 4 (14 ) Electric fuel and other energy-related purchases (59 ) (70 ) (14 ) Other operations & maintenance (1 ) 1 — Interest rate (2) — — (1 ) Total $(45 ) $(63 ) $ (5 ) (1) Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion Energy’s Consolidated Statements of Income. (2) Amounts recorded in Dominion Energy’s Consolidated Statements of Income are classified in interest and related charges.
Virginia Electric and Power Company
Offsetting Assets	The tables below present Virginia Power’s derivative asset and liability balances by type of financial instrument, before and after the effects of offsetting: December 31, 2017 December 31, 2016 Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets Presented Consolidated Balance Sheet Gross Amounts of Recognized Assets Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Assets Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $155 $— $155 $147 $— $147 Interest rate contracts: Over-the-counter — — — 6 — 6 Total derivatives, subject to a master netting or similar arrangement 155 — 155 153 — 153 Total derivatives, not subject to a master netting or similar arrangement 11 — 11 41 — 41 Total $166 $— $166 $194 $— $194 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Offset in the Consolidated Balance Sheet Net Amounts of in the Consolidated Balance Sheet Financial Cash Collateral Received Net Amounts Net Amounts of Assets Presented in Balance Sheet Financial Instruments Cash Collateral Received Net Amounts (millions) Commodity contracts: Over-the-counter $155 $ 4 $— $151 $147 $ 2 $— $145 Interest rate contracts: Over-the-counter — — — — 6 — — 6 Total $155 $ 4 $— $151 $153 $ 2 $— $151
Offsetting Liabilities	December 31, 2017 December 31, 2016 Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Consolidated Balance Sheet Net Amounts of Liabilities Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $ 4 $— $ 4 $ 2 $— $ 2 Interest rate contracts: Over-the-counter 57 — 57 21 — 21 Total derivatives, subject to a master netting or similar arrangement 61 — 61 23 — 23 Total derivatives, not subject to a master netting or similar arrangement 5 — 5 8 — 8 Total $66 $— $66 $31 $— $31 December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Gross Amounts Not Offset in the Net Amounts of Liabilities Presented in the Consolidated Balance Sheet Financial Instruments Cash Collateral Paid Net Amounts Net Amounts of Liabilities Presented Financial Instruments Cash Collateral Paid Net Amounts (millions) Commodity contracts: Over-the-counter $ 4 $ 4 $— $— $ 2 $ 2 $— $— Interest rate contracts: Over-the-counter 57 — — 57 21 — — 21 Total $61 $ 4 $— $57 $23 $ 2 $— $21
Schedule of Volume of Derivative Activity	The following table presents the volume of Virginia Power’s derivative activity at December 31, 2017. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions, except in the case of offsetting transactions, for which they represent the absolute value of the net volume of their long and short positions. Current Noncurrent Natural Gas (bcf): Fixed price (1) 33 5 Basis 79 540 Electricity (MWh): Fixed price (1) 1,453,910 364,990 FTRs 42,582,981 — Interest rate (2) $ 1,150,000,000 $ 300,000,000 (1) Includes options. (2) Maturity is determined based on final settlement period.
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table presents selected information related to losses on cash flow hedges included in AOCI in Virginia Power’s Consolidated Balance Sheet at December 31, 2017: AOCI After-Tax Amounts Expected After-Tax Maximum (millions) Interest rate $(12 ) $(1 ) 384 months Total $(12 ) $(1 )
Fair Value of Derivatives	The following tables present the fair values of Virginia Power’s derivatives and where they are presented in its Consolidated Balance Sheets: Fair Value - Derivatives under Hedge Accounting Fair Value - Derivatives not under Hedge Accounting Total Fair Value (millions) At December 31, 2017 ASSETS Current Assets Commodity $— $ 75 $ 75 Total current derivative assets (1) — 75 75 Noncurrent Assets Commodity — 91 91 Total noncurrent derivative assets — 91 91 Total derivative assets $— $166 $166 LIABILITIES Current Liabilities Commodity $— $ 9 $ 9 Interest rate 44 — 44 Total current derivative liabilities (2) 44 9 53 Noncurrent Liabilities Interest rate 13 — 13 Total noncurrent derivatives liabilities (3) 13 — 13 Total derivative liabilities $57 $ 9 $ 66 At December 31, 2016 ASSETS Current Assets Commodity $— $ 60 $ 60 Interest rate 6 — 6 Total current derivative assets (1) 6 60 66 Noncurrent Assets Commodity — 128 128 Total noncurrent derivative assets — 128 128 Total derivative assets $6 $188 $194 LIABILITIES Current Liabilities Commodity $— $ 10 $ 10 Interest rate 8 — 8 Total current derivative liabilities (2) 8 10 18 Noncurrent Liabilities Interest rate 13 — 13 Total noncurrent derivative liabilities (3) 13 — 13 Total derivative liabilities $21 $ 10 $ 31 (1) Current derivative assets are presented in other current assets in Virginia Power’s Consolidated Balance Sheets. (2) Current derivative liabilities are presented in other current liabilities in Virginia Power’s Consolidated Balance Sheets. (3) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Virginia Power’s Consolidated Balance Sheets.
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following tables present the gains and losses on Virginia Power’s derivatives, as well as where the associated activity is presented in its Consolidated Balance Sheets and Statements of Income: Derivatives in cash flow hedging Amount of Gain (Loss) Recognized in AOCI on (Effective Portion) (1) Amount of Gain (Loss) Reclassified From AOCI to Income Increase (2) (millions) Year Ended December 31, 2017 Derivative type and location of gains (losses): Interest rate (3) $(8 ) $(1 ) $(58 ) Total $(8 ) $(1 ) $(58 ) Year Ended December 31, 2016 Derivative type and location of gains (losses): Interest rate (3) $(3 ) $(1 ) $(26 ) Total $(3 ) $(1 ) $(26 ) Year Ended December 31, 2015 Derivative type and location of gains (losses): Commodity: Electric fuel and other energy-related purchases $(1 ) Total commodity $— $(1 ) $ 4 Interest rate (3) (3 ) — (13 ) Total $(3 ) $(1 ) $ (9 ) (1) Amounts deferred into AOCI have no associated effect in Virginia Power’s Consolidated Statements of Income. (2) Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power’s Consolidated Statements of Income. (3) Amounts recorded in Virginia Power’s Consolidated Statements of Income are classified in interest and related charges.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance	Derivatives not designated as hedging instruments Amount of Gain (Loss) Recognized in Income on Derivatives (1) Year Ended December 31, 2017 2016 2015 (millions) Derivative type and location of gains (losses): Commodity (2) $(57 ) $(70 ) $(13 ) Total $(57 ) $(70 ) $(13 ) (1) Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power’s Consolidated Statements of Income. (2) Amounts recorded in Virginia Power’s Consolidated Statements of Income are classified in electric fuel and other energy-related purchases.
Dominion Energy Gas Holdings, LLC
Offsetting Assets	The tables below present Dominion Energy Gas’ derivative asset and liability balances by type of financial instrument, before and after the effects of offsetting: December 31, 2017 December 31, 2016 Gross Amounts of Assets Gross Amounts Offset in the Net Amounts of Gross Assets Gross Amounts Offset in the Balance Sheet Net Amounts of Presented in the Balance Sheet (millions) Foreign currency contracts: Over-the-counter $32 $— $32 $— $— $— Total derivatives, subject to a master netting or similar arrangement $32 $— $32 $— $— $— December 31, 2017 December 31, 2016 Gross Amounts Not Offset in the Consolidated Balance Sheet Gross Amounts Not Balance Sheet Net Amounts of Balance Sheet Financial Instruments Cash Collateral Received Net Amounts Net Amounts of Balance Sheet Financial Instruments Cash Collateral Received Net Amounts (millions) Foreign currency contracts: Over-the-counter $32 $2 $— $30 $— $— $— $— Total $32 $2 $— $30 $— $— $— $—
Offsetting Liabilities	December 31, 2017 December 31, 2016 Gross Amounts of Gross Amounts Offset in the Net Amounts of Liabilities Presented in the Consolidated Gross Amounts of Gross Amounts Offset in the Net Amounts of Presented in the Consolidated Balance Sheet (millions) Commodity contracts: Over-the-counter $6 $— $6 $ 5 $— $ 5 Foreign currency contracts: Over-the-counter 2 — 2 6 — 6 Total derivatives, subject to a master netting or similar arrangement $8 $— $8 $11 $— $11 December 31, 2017 December 31, 2016 Gross Amounts Not Offset Gross Amounts Not Offset in the Consolidated Net Amounts of Financial Cash Collateral Paid Net Amounts Net Amounts of Financial Cash Collateral Paid Net Amounts (millions) Commodity contracts Over-the-counter $6 $— $— $ 6 $ 5 $— $— $ 5 Foreign currency contracts: Over-the-counter 2 2 — — 6 — — 6 Total $8 $ 2 $— $ 6 $11 $— $— $11
Schedule of Volume of Derivative Activity	The following table presents the volume of Dominion Energy Gas’ derivative activity at December 31, 2017. These volumes are based on open derivative positions and represent the combined absolute value of their long and short positions, except in the case of offsetting transactions, for which they represent the absolute value of the net volume of their long and short positions. Current Noncurrent Natural Gas (bcf): Basis 1 — NGLs (Gal) 40,961,704 8,491,200 Foreign currency (1) $ — $ 280,000,000 (1) Maturity is determined based on final settlement period. Euro equivalent volumes are €250,000,000.
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table presents selected information related to gains (losses) on cash flow hedges included in AOCI in Dominion Energy Gas’ Consolidated Balance Sheet at December 31, 2017: AOCI After-Tax Amounts Expected After-Tax Maximum (millions) Commodities: NGLs $ (4 ) $(4 ) 15 months Interest rate (25 ) (3 ) 324 months Foreign currency 6 (1 ) 102 months Total $(23 ) $(8 )
Fair Value of Derivatives	The following tables present the fair values of Dominion Energy Gas’ derivatives and where they are presented in its Consolidated Balance Sheets: Fair Value- Under Accounting Fair Value- Not Under Accounting Total Fair Value (millions) At December 31, 2017 ASSETS Noncurrent Assets Foreign currency $32 $— $32 Total noncurrent derivative assets (1) 32 — 32 Total derivative assets $32 $— $32 LIABILITIES Current Liabilities Commodity $ 6 $— $ 6 Foreign currency 2 — 2 Total current derivative liabilities (2) 8 — 8 Total derivative liabilities $ 8 $— $ 8 At December 31, 2016 LIABILITIES Current Liabilities Commodity $ 4 $— $ 4 Foreign currency 3 — 3 Total current derivative liabilities (2) 7 — 7 Noncurrent Liabilities Commodity 1 — 1 Foreign currency 3 — 3 Total noncurrent derivative liabilities (3) 4 — 4 Total derivative liabilities $11 $— $11 (1) Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy Gas’ Consolidated Balance Sheets. (2) Current derivative liabilities are presented in other current liabilities in Dominion Energy Gas’ Consolidated Balance Sheets. (3) Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy Gas’ Consolidated Balance Sheets.
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location	The following tables present the gains and losses on Dominion Energy Gas’ derivatives, as well as where the associated activity is presented in its Consolidated Balance Sheets and Statements of Income: Derivatives in cash flow hedging relationships Amount of Gain Derivatives (1) Amount of (millions) Year Ended December 31, 2017 Derivative Type and Location of Gains (Losses): Commodity: Operating revenue $ (8 ) Total commodity $(10 ) $ (8 ) Interest rate (2) — (5 ) Foreign currency (3) 18 20 Total $ 8 $ 7 Year Ended December 31, 2016 Derivative Type and Location of Gains (Losses): Commodity: Operating revenue $ 4 Total commodity $(12 ) $ 4 Interest rate (2) (8 ) (2 ) Foreign currency (3) (6 ) (17 ) Total $(26 ) $(15 ) Year Ended December 31, 2015 Derivative Type and Location of Gains (Losses): Commodity: Operating revenue $ 6 Total commodity $ 16 $ 6 Interest rate (2) (6) — Total $ 10 $ 6 (1) Amounts deferred into AOCI have no associated effect in Dominion Energy Gas’ Consolidated Statements of Income. (2) Amounts recorded in Dominion Energy Gas’ Consolidated Statements of Income are classified in interest and related charges. (3) Amounts recorded in Dominion Energy Gas’ Consolidated Statements of Income are classified in other income.
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance	Derivatives not designated as hedging instruments Amount of Gain (Loss) Recognized in Income on Derivatives Year Ended December 31, 2017 2016 2015 (millions) Derivative type and location of gains (losses): Commodity Operating revenue $— $1 $6 Total $— $1 $6

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share Computation	The following table presents the calculation of Dominion Energy’s basic and diluted EPS: 2017 2016 2015 (millions, except EPS) Net income attributable to Dominion Energy $ 2,999 $ 2,123 $ 1,899 Average shares of common stock outstanding – Basic 636.0 616.4 592.4 Net effect of dilutive securities (1) — 0.7 1.3 Average shares of common stock outstanding – Diluted 636.0 617.1 593.7 Earnings Per Common Share – Basic $ 4.72 $ 3.44 $ 3.21 Earnings Per Common Share – Diluted $ 4.72 $ 3.44 $ 3.20 (1) Dilutive securities consist primarily of the 2013 Equity Units for 2016 and 2015. See Note 17 for more information.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Available-For-Sale Securities	Dominion Energy’s decommissioning trust funds are summarized below: Amortized Cost Total Unrealized Gains (1) Total Unrealized Losses (1) Fair (millions) At December 31, 2017 Marketable equity securities: U.S. $1,569 $1,857 $ — $3,426 Fixed income: Corporate debt instruments 430 15 (1 ) 444 Government securities 1,039 27 (5 ) 1,061 Common/collective trust funds 60 — — 60 Cost method investments 68 — — 68 Cash equivalents and other (2) 34 — — 34 Total $3,200 $1,899 $ (6 ) (3) $5,093 At December 31, 2016 Marketable equity securities: U.S. $1,449 $1,408 $ — $2,857 Fixed income: Corporate debt instruments 478 13 (4 ) 487 Government securities 978 22 (8) 992 Common/collective trust funds 67 — — 67 Cost method investments 69 — — 69 Cash equivalents and other (2) 12 — — 12 Total $3,053 $1,443 $(12 ) (3) $4,484 (1) Included in AOCI and the nuclear decommissioning trust regulatory liability as discussed in Note 2. (2) Includes pending sales of securities of $5 million and $9 million at December 31, 2017 and 2016, respectively. (3) The fair value of securities in an unrealized loss position was $565 million and $576 million at December 31, 2017 and 2016, respectively.
Investments Classified by Contractual Maturity Date	The fair value of Dominion Energy’s marketable debt securities held in nuclear decommissioning trust funds at December 31, 2017 by contractual maturity is as follows: Amount (millions) Due in one year or less $ 151 Due after one year through five years 385 Due after five years through ten years 370 Due after ten years 659 Total $ 1,565
Marketable Securities	Presented below is selected information regarding Dominion Energy’s marketable equity and debt securities held in nuclear decommissioning trust funds: Year Ended December 31, 2017 2016 2015 (millions) Proceeds from sales $ 1,831 $ 1,422 $ 1,340 Realized gains (1) 166 128 219 Realized losses (1) 71 55 84 (1) Includes realized gains and losses recorded to the nuclear decommissioning trust regulatory liability as discussed in Note 2.
Other Than Temporary Impairment Losses On Investment Securities	Dominion Energy recorded other-than-temporary impairment losses on investments held in nuclear decommissioning trust funds as follows: Year Ended December 31, 2017 2016 2015 (millions) Total other-than-temporary impairment losses (1) $ 44 $ 51 $ 66 Losses recorded to the nuclear decomissioning trust regulatory liability (16 ) (16 ) (26 ) Losses recognized in other comprehensive income (before taxes) (5 ) (12 ) (9 ) Net impairment losses recognized in earnings $ 23 $ 23 $ 31 (1) Amounts include other-than-temporary impairment losses for debt securities of $5 million, $13 million and $9 million at December 31, 2017, 2016 and 2015, respectively.
Investments Accounts Under Equity Method of Accounting	Investments that Dominion Energy and Dominion Energy Gas account for under the equity method of accounting are as follows: Company Ownership % Investment Balance Description As of December 31, 2017 2016 (millions) Dominion Energy Blue Racer 50 % $ 691 $ 677 Midstream gas and Iroquois 50 % (1) 311 316 Gas transmission system Atlantic Coast Pipeline 48 % 382 256 Gas transmission system Fowler Ridge 50 % 81 116 Wind-powered merchant NedPower 50 % — (2) 112 Wind-powered merchant Other various 79 84 Total $ 1,544 $ 1,561 Dominion Energy Gas Iroquois 24.07 % $ 95 $ 98 Gas transmission system Total $ 95 $ 98 (1) Comprised of Dominion Energy Midstream’s interest of 25.93% and Dominion Energy Gas’ interest of 24.07%. See Note 15 for more information. (2) Liability of $17 million associated with NedPower recorded to other deferred credits and other liabilities, on the Consolidated Balance Sheets as of December 31, 2017. See additional discussion of NedPower below.
Virginia Electric and Power Company
Available-For-Sale Securities	Virginia Power’s decommissioning trust funds are summarized below: Amortized Cost Total Gains (1) Total Losses (1) Fair (millions) At December 31, 2017 Marketable equity securities: U.S. $ 734 $831 $— $1,565 Fixed income: Corporate debt instruments 216 8 — 224 Government securities 482 13 (2 ) 493 Common/collective trust funds 27 — — 27 Cost method investments 68 — — 68 Cash equivalents and other (2) 22 — — 22 Total $1,549 $852 $(2 ) (3) $2,399 At December 31, 2016 Marketable equity securities: U.S. $ 677 $624 $— $1,301 Fixed income: Corporate debt instruments 274 6 (4 ) 276 Government securities 420 9 (2 ) 427 Common/collective trust funds 26 — — 26 Cost method investments 69 — — 69 Cash equivalents and other (2) 7 — — 7 Total $1,473 $639 $(6 ) (3) $2,106 (1) Included in AOCI and the nuclear decommissioning trust regulatory liability as discussed in Note 2. (2) Includes pending sales of securities of $6 million and $7 million at December 31, 2017 and 2016, respectively. (3) The fair value of securities in an unrealized loss position was $234 million and $287 million at December 31, 2017 and 2016, respectively.
Investments Classified by Contractual Maturity Date	The fair value of Virginia Power’s marketable debt securities at December 31, 2017, by contractual maturity is as follows: Amount (millions) Due in one year or less $ 32 Due after one year through five years 165 Due after five years through ten years 199 Due after ten years 348 Total $744
Marketable Securities	Presented below is selected information regarding Virginia Power’s marketable equity and debt securities held in nuclear decommissioning trust funds. Year Ended December 31, 2017 2016 2015 (millions) Proceeds from sales $ 849 $ 733 $ 639 Realized gains (1) 75 63 110 Realized losses (1) 30 27 43 (1) Includes realized gains and losses recorded to the nuclear decommissioning trust regulatory liability as discussed in Note 2.
Other Than Temporary Impairment Losses On Investment Securities	Virginia Power recorded other-than-temporary impairment losses on investments held in nuclear decommissioning trust funds as follows: Year Ended December 31, 2017 2016 2015 (millions) Total other-than-temporary impairment losses (1) $ 20 $ 26 $ 36 Losses recorded to the nuclear decomissioning trust regulatory liability (16 ) (16 ) (26 ) Losses recognized in other comprehensive income (before taxes) (2 ) (7 ) (6 ) Net impairment losses recognized in earnings $ 2 $ 3 $ 4 (1) Amounts include other-than-temporary impairment losses for debt securities of $2 million, $8 million and $6 million at December 31, 2017, 2016 and 2015, respectively.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Major classes of property, plant and equipment and their respective balances for the Companies are as follows: At December 31, 2017 2016 (millions) Dominion Energy Utility: Generation $ 17,602 $ 17,147 Transmission 15,335 14,315 Distribution 17,408 16,381 Storage 2,887 2,814 Nuclear fuel 1,599 1,537 Gas gathering and processing 219 216 Oil and gas 1,720 1,652 General and other 1,514 1,450 Plant under construction 7,765 6,254 Total utility 66,049 61,766 Nonutility: Merchant generation-nuclear 1,452 1,419 Merchant generation-other 4,992 4,149 Nuclear fuel 968 897 Gas gathering and processing 630 619 Other-including plant under construction 732 706 Total nonutility 8,774 7,790 Total property, plant and equipment $ 74,823 $ 69,556 Virginia Power Utility: Generation $ 17,602 $ 17,147 Transmission 8,332 7,871 Distribution 11,151 10,573 Nuclear fuel 1,599 1,537 General and other 794 745 Plant under construction 2,840 2,146 Total utility 42,318 40,019 Nonutility-other 11 11 Total property, plant and equipment $ 42,329 $ 40,030 Dominion Energy Gas Utility: Transmission $ 4,732 $ 4,231 Distribution 3,267 3,019 Storage 1,688 1,627 Gas gathering and processing 202 198 General and other 216 184 Plant under construction 293 448 Total utility 10,398 9,707 Nonutility: Gas gathering and processing 630 $ 619 Other-including plant under construction 145 149 Total nonutility 775 768 Total property, plant and equipment $ 11,173 $ 10,475
Share of Jointly-Owned Power Stations	Dominion Energy’s and Virginia Power’s proportionate share of jointly-owned power stations at December 31, 2017 is as follows: Bath County Pumped Storage Station (1) North Anna Units 1 and 2 (1) Clover Power Station (1) Millstone Unit 3 (2) (millions, except percentages) Ownership interest 60 % 88.4 % 50 % 93.5 % Plant in service $ 1,059 $ 2,504 $ 589 $ 1,217 Accumulated depreciation (612 ) (1,263 ) (231 ) (381 ) Nuclear fuel — 745 — 552 Accumulated amortization of nuclear fuel — (607 ) — (427 ) Plant under construction 2 92 6 68 (1) Units jointly owned by Virginia Power. (2) Unit jointly owned by Dominion Energy.

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Segment allocation of goodwill	The changes in Dominion Energy’s and Dominion Energy Gas’ carrying amount and segment allocation of goodwill are presented below: Power Gas Power Corporate and Other (1) Total (millions) Dominion Energy Balance at December 31, 2015 (2) $1,422 $ 946 $926 $— $3,294 Dominion Energy Questar Combination — 3,105 (3) — — 3,105 Balance at December 31, 2016 (2) $1,422 $4,051 $926 $— $6,399 Dominion Energy Questar Combination — 6 (3) — — 6 Balance at December 31, 2017 (2) $1,422 $4,057 $926 $— $6,405 Dominion Energy Gas Balance at December 31, 2015 (2) $ — $ 542 $ — $— $ 542 No events affecting goodwill — — — — — Balance at December 31, 2016 (2) $ — $ 542 $ — $— $ 542 No events affecting goodwill — — — — — Balance at December 31, 2017 (2) $ — $ 542 $ — $— $ 542 (1) Goodwill recorded at the Corporate and Other segment is allocated to the primary operating segments for goodwill impairment testing purposes. (2) Goodwill amounts do not contain any accumulated impairment losses. (3) See Note 3.
Components of intangible assets	The components of intangible assets are as follows: 2017 2016 At December 31, Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization (millions) Dominion Energy Software, licenses and other $1,043 $358 $955 $337 Virginia Power Software, licenses and other $ 347 $114 $326 $101 Dominion Energy Gas Software, licenses and other $ 165 $ 56 $147 $ 49
Annual amortization expense of intangible assets	Annual amortization expense for these intangible assets is estimated to be as follows: 2018 2019 2020 2021 2022 (millions) Dominion Energy $ 78 $ 68 $ 56 $ 43 $ 37 Virginia Power $ 30 $ 26 $ 20 $ 13 $ 9 Dominion Energy Gas $ 13 $ 13 $ 12 $ 11 $ 10

Regulatory Assets and Liabili46

Regulatory Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Regulated Operations [Abstract]
Schedule of Regulatory Liabilities	Regulatory assets and liabilities include the following: At December 31, 2017 2016 (millions) Dominion Energy Regulatory assets: Deferred rate adjustment clause costs (1) $ 70 $ 63 Deferred nuclear refueling outage costs (2) 54 71 Unrecovered gas costs (3) 38 19 Deferred cost of fuel used in electric generation (4) 23 — Other 109 91 Regulatory assets-current 294 244 Unrecognized pension and other postretirement benefit costs (5) 1,336 1,401 Deferred rate adjustment clause costs (1) 401 329 Derivatives (6) 223 174 PJM transmission rates (7) 222 192 Utility reform legislation (8) 147 99 Income taxes recoverable through future rates (9) 32 123 Other 119 155 Regulatory assets-noncurrent 2,480 2,473 Total regulatory assets $ 2,774 $ 2,717 Regulatory liabilities: Provision for future cost of removal and AROs (10) $ 101 $ — PIPP (11) 20 28 Deferred cost of fuel used in electric generation (4) 8 61 Other 64 74 Regulatory liabilities-current (12) 193 163 Income taxes refundable through future rates (13) 4,058 — Provision for future cost of removal and AROs (10) 1,384 1,427 Nuclear decommissioning trust (14) 1,121 902 Derivatives (6) 69 69 Other 284 224 Regulatory liabilities-noncurrent 6,916 2,622 Total regulatory liabilities $ 7,109 $ 2,785 Virginia Power Regulatory assets: Deferred rate adjustment clause costs (1) $ 56 $ 51 Deferred nuclear refueling outage costs (2) 54 71 Deferred cost of fuel used in electric generation (4) 23 — Other 72 57 Regulatory assets-current 205 179 Deferred rate adjustment clause costs (1) 312 246 PJM transmission rates (7) 222 192 Derivatives (6) 190 133 Income taxes recoverable through future rates (9) — 76 Other 86 123 Regulatory assets-noncurrent 810 770 Total regulatory assets $ 1,015 $ 949 Regulatory liabilities: Provision for future cost of removal (10) $ 80 $ — Deferred cost of fuel used in electric generation (4) 8 61 Other 39 54 Regulatory liabilities-current (12) 127 115 Income taxes refundable through future rates (13) 2,581 — Nuclear decommissioning trust (14) 1,121 902 Provision for future cost of removal (10) 915 946 Derivatives (6) 69 69 Other 74 45 Regulatory liabilities-noncurrent 4,760 1,962 Total regulatory liabilities $ 4,887 $ 2,077 Dominion Energy Gas Regulatory assets: Deferred rate adjustment clause costs (1) $ 14 $ 12 Unrecovered gas costs (3) 8 12 Other 4 2 Regulatory assets-current (15) 26 26 Unrecognized pension and other postretirement benefit costs (5) 258 358 Utility reform legislation (8) 147 99 Deferred rate adjustment clause costs (1) 89 79 Income taxes recoverable through future rates (9) — 23 Other 17 18 Regulatory assets-noncurrent 511 577 Total regulatory assets $ 537 $ 603 Regulatory liabilities: PIPP (11) $ 20 $ 28 Provision for future cost of removal and AROs (10) 13 — Other 5 7 Regulatory liabilities-current (12) 38 35 Income taxes refundable through future rates (13) 998 — Provision for future cost of removal and AROs (10) 160 174 Other 69 45 Regulatory liabilities-noncurrent 1,227 219 Total regulatory liabilities $ 1,265 $ 254 (1) Primarily reflects deferrals under the electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects for Virginia Power and deferrals of costs associated with certain current and prospective rider projects for Dominion Energy Gas. See Note 13 for more information. (2) Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months. (3) Reflects unrecovered gas costs at regulated gas operations, which are recovered through filings with the applicable regulatory authority. (4) Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Dominion Energy’s and Virginia Power’s generation operations. See Note 13 for more information. (5) Represents unrecognized pension and other postretirement employee benefit costs expected to be recovered through future rates generally over the expected remaining service period of plan participants by certain of Dominion Energy’s and Dominion Energy Gas’ rate-regulated subsidiaries. (6) As discussed under Derivative Instruments in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers. (7) Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information. (8) Ohio legislation under House Bill 95, which became effective in September 2011. This law updates natural gas legislation by enabling gas companies to include more up-to-date (9) Amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity and depreciation of property, plant and equipment for which deferred income taxes were not recognized for ratemaking purposes, including amounts attributable to tax rate changes. See below for discussion of the 2017 Tax Reform Act. (10) Rates charged to customers by the Companies’ regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement. (11) Under PIPP, eligible customers can make reduced payments based on their ability to pay. The difference between the customer’s total bill and the PIPP plan amount is deferred and collected or returned annually under the PIPP rate adjustment clause according to East Ohio tariff provisions. See Note 13 for more information. (12) Current regulatory liabilities are presented in other current liabilities in the Consolidated Balance Sheets of the Companies. (13) Amounts recorded to pass the effect of reduced income tax rates from the 2017 Tax Reform Act to customers in future periods, which will reverse at the weighted average tax rate that was used to build the reserves over the remaining book life of the property, net of amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity. (14) Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon) for the future decommissioning of Virginia Power’s utility nuclear generation stations, in excess of the related AROs. (15) Current regulatory assets are presented in other current assets in the Consolidated Balance Sheets of Dominion Energy Gas.
Schedule of Regulatory Assets	Regulatory assets and liabilities include the following: At December 31, 2017 2016 (millions) Dominion Energy Regulatory assets: Deferred rate adjustment clause costs (1) $ 70 $ 63 Deferred nuclear refueling outage costs (2) 54 71 Unrecovered gas costs (3) 38 19 Deferred cost of fuel used in electric generation (4) 23 — Other 109 91 Regulatory assets-current 294 244 Unrecognized pension and other postretirement benefit costs (5) 1,336 1,401 Deferred rate adjustment clause costs (1) 401 329 Derivatives (6) 223 174 PJM transmission rates (7) 222 192 Utility reform legislation (8) 147 99 Income taxes recoverable through future rates (9) 32 123 Other 119 155 Regulatory assets-noncurrent 2,480 2,473 Total regulatory assets $ 2,774 $ 2,717 Regulatory liabilities: Provision for future cost of removal and AROs (10) $ 101 $ — PIPP (11) 20 28 Deferred cost of fuel used in electric generation (4) 8 61 Other 64 74 Regulatory liabilities-current (12) 193 163 Income taxes refundable through future rates (13) 4,058 — Provision for future cost of removal and AROs (10) 1,384 1,427 Nuclear decommissioning trust (14) 1,121 902 Derivatives (6) 69 69 Other 284 224 Regulatory liabilities-noncurrent 6,916 2,622 Total regulatory liabilities $ 7,109 $ 2,785 Virginia Power Regulatory assets: Deferred rate adjustment clause costs (1) $ 56 $ 51 Deferred nuclear refueling outage costs (2) 54 71 Deferred cost of fuel used in electric generation (4) 23 — Other 72 57 Regulatory assets-current 205 179 Deferred rate adjustment clause costs (1) 312 246 PJM transmission rates (7) 222 192 Derivatives (6) 190 133 Income taxes recoverable through future rates (9) — 76 Other 86 123 Regulatory assets-noncurrent 810 770 Total regulatory assets $ 1,015 $ 949 Regulatory liabilities: Provision for future cost of removal (10) $ 80 $ — Deferred cost of fuel used in electric generation (4) 8 61 Other 39 54 Regulatory liabilities-current (12) 127 115 Income taxes refundable through future rates (13) 2,581 — Nuclear decommissioning trust (14) 1,121 902 Provision for future cost of removal (10) 915 946 Derivatives (6) 69 69 Other 74 45 Regulatory liabilities-noncurrent 4,760 1,962 Total regulatory liabilities $ 4,887 $ 2,077 Dominion Energy Gas Regulatory assets: Deferred rate adjustment clause costs (1) $ 14 $ 12 Unrecovered gas costs (3) 8 12 Other 4 2 Regulatory assets-current (15) 26 26 Unrecognized pension and other postretirement benefit costs (5) 258 358 Utility reform legislation (8) 147 99 Deferred rate adjustment clause costs (1) 89 79 Income taxes recoverable through future rates (9) — 23 Other 17 18 Regulatory assets-noncurrent 511 577 Total regulatory assets $ 537 $ 603 Regulatory liabilities: PIPP (11) $ 20 $ 28 Provision for future cost of removal and AROs (10) 13 — Other 5 7 Regulatory liabilities-current (12) 38 35 Income taxes refundable through future rates (13) 998 — Provision for future cost of removal and AROs (10) 160 174 Other 69 45 Regulatory liabilities-noncurrent 1,227 219 Total regulatory liabilities $ 1,265 $ 254 (1) Primarily reflects deferrals under the electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects for Virginia Power and deferrals of costs associated with certain current and prospective rider projects for Dominion Energy Gas. See Note 13 for more information. (2) Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months. (3) Reflects unrecovered gas costs at regulated gas operations, which are recovered through filings with the applicable regulatory authority. (4) Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Dominion Energy’s and Virginia Power’s generation operations. See Note 13 for more information. (5) Represents unrecognized pension and other postretirement employee benefit costs expected to be recovered through future rates generally over the expected remaining service period of plan participants by certain of Dominion Energy’s and Dominion Energy Gas’ rate-regulated subsidiaries. (6) As discussed under Derivative Instruments in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers. (7) Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information. (8) Ohio legislation under House Bill 95, which became effective in September 2011. This law updates natural gas legislation by enabling gas companies to include more up-to-date (9) Amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity and depreciation of property, plant and equipment for which deferred income taxes were not recognized for ratemaking purposes, including amounts attributable to tax rate changes. See below for discussion of the 2017 Tax Reform Act. (10) Rates charged to customers by the Companies’ regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement. (11) Under PIPP, eligible customers can make reduced payments based on their ability to pay. The difference between the customer’s total bill and the PIPP plan amount is deferred and collected or returned annually under the PIPP rate adjustment clause according to East Ohio tariff provisions. See Note 13 for more information. (12) Current regulatory liabilities are presented in other current liabilities in the Consolidated Balance Sheets of the Companies. (13) Amounts recorded to pass the effect of reduced income tax rates from the 2017 Tax Reform Act to customers in future periods, which will reverse at the weighted average tax rate that was used to build the reserves over the remaining book life of the property, net of amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity. (14) Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon) for the future decommissioning of Virginia Power’s utility nuclear generation stations, in excess of the related AROs. (15) Current regulatory assets are presented in other current assets in the Consolidated Balance Sheets of Dominion Energy Gas.

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligation Disclosure [Abstract]
Changes to Asset Retirement Obligations	The changes to AROs during 2016 and 2017 were as follows: Amount (millions) Dominion Energy AROs at December 31, 2015 $ 2,103 Obligations incurred during the period (1) 204 Obligations settled during the period (171 ) Revisions in estimated cash flows (2) 245 Accretion 104 AROs at December 31, 2016 (3) $ 2,485 Obligations incurred during the period 37 Obligations settled during the period (214 ) Revisions in estimated cash flows 7 Accretion 117 AROs at December 31, 2017 (3) $ 2,432 Virginia Power AROs at December 31, 2015 $ 1,247 Obligations incurred during the period 9 Obligations settled during the period (115 ) Revisions in estimated cash flows (2) 245 Accretion 57 AROs at December 31, 2016 $ 1,443 Obligations incurred during the period 11 Obligations settled during the period (152 ) Revisions in estimated cash flows (1 ) Accretion 64 AROs at December 31, 2017 $ 1,365 Dominion Energy Gas AROs at December 31, 2015 $ 149 Obligations incurred during the period 6 Obligations settled during the period (8 ) Accretion 9 AROs at December 31, 2016 (4) $ 156 Obligations incurred during the period 2 Obligations settled during the period (7 ) Accretion 9 AROs at December 31, 2017 (4) $ 160 (1) Primarily reflects AROs assumed in the Dominion Energy Questar Combination. See Note 3 for further information. (2) Primarily reflects future ash pond and landfill closure costs at certain utility generation facilities. See Note 22 for further information. (3) Includes $249 million and $263 million reported in other current liabilities at December 31, 2016, and 2017, respectively. (4) Includes $147 million and $146 million reported in other deferred credits and other liabilities, with the remainder recorded in other current liabilities, at December 31, 2016 and 2017, respectively.

Short-Term Debt and Credit Ag48

Short-Term Debt and Credit Agreements (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Line of Credit Facilities	Commercial paper and letters of credit outstanding, as well as capacity available under credit facilities, were as follows: Facility Limit Outstanding Commercial Paper (2) Outstanding Letters of Credit Facility Capacity Available (millions) At December 31, 2017 Joint revolving credit facility (1) $ 5,000 $3,298 $ $ 1,702 Joint revolving credit facility (1) 500 — 76 424 Total $ 5,500 $3,298 $76 $ 2,126 At December 31, 2016 Joint revolving credit facility (1) $ 5,000 $3,155 $ $ 1,845 Joint revolving credit facility (1) 500 — 85 415 Total $ 5,500 $3,155 $85 $ 2,260 (1) These credit facilities mature in April 2020 and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $2.0 billion of letters of credit. (2) The weighted-average interest rates of the outstanding commercial paper supported by Dominion Energy’s credit facilities were 1.61% and 1.05% at December 31, 2017 and 2016, respectively.
Virginia Electric and Power Company
Schedule of Line of Credit Facilities	Virginia Power’s share of commercial paper and letters of credit outstanding under its joint credit facilities with Dominion Energy, Dominion Energy Gas and Questar Gas were as follows: Facility Limit (1) Outstanding Commercial Paper (2) Outstanding Letters of Credit (millions) At December 31, 2017 Joint revolving credit facility (1) $5,000 $542 $— Joint revolving credit facility (1) 500 — — Total $5,500 $542 $— At December 31, 2016 Joint revolving credit facility (1) $5,000 $ 65 $— Joint revolving credit facility (1) 500 — 1 Total $5,500 $ 65 $ 1 (1) The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Sub-limits sub-limit sub-limit, sub-limit sub-limit, (2) The weighted-average interest rates of the outstanding commercial paper supported by these credit facilities were 1.65% and 0.97% at December 31, 2017 and 2016, respectively.
Dominion Energy Gas Holdings, LLC
Schedule of Line of Credit Facilities	Dominion Energy Gas’ share of commercial paper and letters of credit outstanding under its joint credit facilities with Dominion Energy, Virginia Power and Questar Gas were as follows: Facility Limit (1) Outstanding Commercial Paper (2) Outstanding Letters of Credit (millions) At December 31, 2017 Joint revolving credit facility (1) $1,000 $629 $— Joint revolving credit facility (1) 500 — — Total $1,500 $629 $— At December 31, 2016 Joint revolving credit facility (1) $1,000 $460 $— Joint revolving credit facility (1) 500 — — Total $1,500 $460 $— (1) A maximum of a combined $1.5 billion of the facilities is available to Dominion Energy Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Sub-limits sub-limit sub-limit, sub-limit sub-limit, (2) The weighted-average interest rate of the outstanding commercial paper supported by these credit facilities was 1.57% and 1.00% at December 31, 2017 and 2016, respectively.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long term Debt	At December 31, 2017 Weighted- average Coupon (1) 2017 2016 (millions, except percentages) Dominion Energy Gas Holdings, LLC: Unsecured Senior Notes: 2.5% and 2.8%, due 2019 and 2020 2.68 % $ 1,150 $ 1,150 2.875% to 4.8%, due 2023 to 2044 (2) 3.90 % 2,450 2,413 Dominion Energy Gas Holdings, LLC total principal $ 3,600 $ 3,563 Unamortized discount and debt issuance costs (30 ) (35 ) Dominion Energy Gas Holdings, LLC total long-term debt $ 3,570 $ 3,528 Virginia Electric and Power Company: Unsecured Senior Notes: 1.2% to 7.25%, due 2017 to 2022 3.92 % $ 1,950 $ 2,554 2.75% to 8.875%, due 2023 to 2047 4.53 % 8,690 7,190 Tax-Exempt (3) Variable rates, due 2017 to 2027 1.27 % 100 175 1.75% to 5.6%, due 2023 to 2041 2.25 % 678 678 Virginia Electric and Power Company total principal $ 11,418 $ 10,597 Securities due within one year 4.17 % (850 ) (678 ) Unamortized discount, premium and debt issuances costs, net (72 ) (67 ) Virginia Electric and Power Company total long-term debt $ 10,496 $ 9,852 Dominion Energy, Inc.: Unsecured Senior Notes: Variable rates, due 2019 and 2020 1.99 % $ 800 $ — 1.25% to 6.4%, due 2017 to 2022 2.95 % 5,800 5,750 2.85% to 7.0%, due 2024 to 2044 4.72 % 5,049 4,649 Tax-Exempt (4) — 75 Unsecured Junior Subordinated Notes: 2.579% to 4.104%, due 2019 to 2021 3.08 % 2,100 1,100 Payable to Affiliated Trust, 8.4% due 2031 8.40 % 10 10 Enhanced Junior Subordinated Notes: 5.25% and 5.75%, due 2054 and 2076 5.48 % 1,485 1,485 Variable rates, due 2066 4.15 % 422 422 Remarketable Subordinated Notes, 1.5% and 2.0%, due 2020 to 2024 2.00 % 1,400 2,400 Unsecured Debentures and Senior Notes ( 5 ) 6.8% and 6.875%, due 2026 and 2027 6.81 % 89 89 Term Loan, variable rate, due 2017 ( 6 ) — 250 Unsecured Senior and Medium-Term Notes (6) 5.31% to 6.85%, due 2017 and 2018 5.72 % 120 135 2.98% to 7.20%, due 2024 to 2051 4.37 % 600 500 Term Loans, variable rates, due 2023 and 2024 ( 7 ) 3.74 % 638 405 Tax-Exempt ( 8 ) 1.55 % 27 27 Dominion Energy Midstream Partners, LP: Term Loan, variable rate, due 2019 2.74 % 300 300 Unsecured Senior and Medium-Term Notes, 5.83% and 6.48%, due 2018 (9) 5.84 % 255 255 Unsecured Senior Notes, 4.875%, due 2041 ( 9 ) 4.88 % 180 180 Dominion Energy Gas Holdings, LLC total principal (from above) 3,600 3,563 Virginia Electric and Power Company total principal (from above) 11,418 10,597 Dominion Energy, Inc. total principal $ 34,293 $ 32,192 Fair value hedge valuation ( 10 ) (22 ) (1 ) Securities due within one year ( 11) (12 ) 3.44 % (3,078 ) (1,709 ) Unamortized discount, premium and debt issuance costs, net (245 ) (251 ) Dominion Energy, Inc. total long-term debt $ 30,948 $ 30,231 (1) Represents weighted-average coupon rates for debt outstanding as of December 31, 2017. (2) Amount includes foreign currency remeasurement adjustments. (3) These financings relate to certain pollution control equipment at Virginia Power’s generating facilities. As of December 31, 2017, certain variable rate tax-exempt tax-exempt (4) Represents variable rate Massachusetts Development Finance Agency Solid Waste Disposal Revenue Bonds due in 2041 repaid in August 2017. (5) Represents debt assumed by Dominion Energy from the merger of its former CNG subsidiary. (6) Represents debt obligations of Dominion Energy Questar or Questar Gas. See Note 3 for more information. (7) Represents debt associated with SBL Holdco and Dominion Solar Projects III, Inc. The debt is nonrecourse to Dominion Energy and is secured by SBL Holdco’s and Dominion Solar Projects III, Inc.’s interest in certain merchant solar facilities. (8) Represents debt obligations of a DGI subsidiary. (9) Represents debt obligations of Dominion Energy Questar Pipeline. See Note 3 for more information. (10) Represents the valuation of certain fair value hedges associated with Dominion Energy’s fixed rate debt. (11) Excludes $250 million of Dominion Energy Questar Pipeline’s senior notes that matured in February 2018 which were repaid using proceeds from the January 2018 issuance, through private placement, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively. (12) Includes $20 million of estimated mandatory prepayments due within one year based on estimated cash flows in excess of debt service at SBL Holdco and Dominion Solar Projects III, Inc.
Scheduled Principal Payments of Long-Term Debt	Based on stated maturity dates rather than early redemption dates that could be elected by instrument holders, the scheduled principal payments of long-term debt at December 31, 2017, were as follows: 2018 2019 2020 2021 2022 Thereafter Total (millions, except percentages) Dominion Energy Gas $ — $ 450 $ 700 $ — $ — $ 2,450 $ 3,600 Weighted-average Coupon 2.50 % 2.80 % 3.90 % Virginia Power Unsecured Senior Notes $ 850 $ 350 $ — $ — $ 750 $ 8,690 $ 10,640 Tax-Exempt — — — — — 778 778 Total $ 850 $ 350 $ — $ — $ 750 $ 9,468 $ 11,418 Weighted-average Coupon 4.17 % 5.00 % 3.15 % 4.33 % Dominion Energy Term Loans (1) $ 36 $ 336 $ 35 $ 35 $ 34 $ 462 $ 938 Unsecured Senior Notes ( 2 ) 3,275 3,400 1,000 900 1,500 17,058 27,133 Tax-Exempt — — — — — 805 805 Unsecured Junior Subordinated Notes Payable to Affiliated Trusts — — — — — 10 10 Unsecured Junior Subordinated Notes — 550 1,000 550 — — 2,100 Enhanced Junior Subordinated Notes — — — — — 1,907 1,907 Remarketable Subordinated Notes — — — 700 — 700 1,400 Total $ 3,311 $ 4,286 $ 2,035 $ 2,185 $ 1,534 $ 20,942 $ 34,293 Weighted-average Coupon 3.62 % 2.89 % 2.58 % 3.12 % 2.97 % 4.38 % (1) Excludes mandatory prepayments associated with SBL Holdco and Dominion Solar Projects III, Inc. based on cash flows in excess of debt service. At December 31, 2017, $20 million of estimated mandatory prepayments due within one year were included in securities due within one year in Dominion Energy’s Consolidated Balance Sheets. (2) In February 2018, $250 million of Dominion Energy Questar Pipeline’s senior notes were repaid using proceeds from the January 2018 issuance, through private placements, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively. As a result, at December 31, 2017, $250 million was included in long-term debt in the Consolidated Balance Sheets.
Schedule of Capital Units	Selected information about Dominion Energy’s equity units is presented below: Issuance Date Units Issued Total Net Proceeds Total Long-term Debt RSN Annual Interest Rate Stock Purchase Contract Annual Rate Stock Purchase Contract Liability (1) Stock Purchase Settlement Date (millions, except interest rates) 8/15/2016 (2) 28 $ 1,374.8 $1,400.0 2.000 % (3) 4.750 % $190.6 8/15/2019 (1) Payments of $101 million and $94 million were made in 2017 and 2016, respectively, including payments for the remarketed 2013 Series A and B notes and the remarketed 2014 Series A notes. The stock purchase contract liability was $111 million and $212 million at December 31, 2017 and 2016, respectively. (2) The maturity dates of the $700 million Series A-1 A-2 (3) Annual interest rate applies to each of the Series A-1 A-2

EQUITY (Tables)

EQUITY (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Accumulated Other Comprehensive Income (Loss)	Presented in the table below is a summary of AOCI by component: At December 31, 2017 2016 (millions) Dominion Energy Net deferred losses on derivatives-hedging activities, net of tax of $188 and $173 $ (301 ) $ (280 ) Net unrealized gains on nuclear decommissioning trust funds, net of tax of $(419) and $(318) 747 569 Net unrecognized pension and other postretirement benefit costs, net of tax of $692 and $691 (1,101 ) (1,082 ) Other comprehensive loss from equity method investees, net of tax of $2 and $4 (3 ) (6 ) Total AOCI, including noncontrolling interest $ (658 ) $ (799 ) Less other comprehensive income attributable to noncontrolling interest 1 — Total AOCI, excluding noncontrolling interest $ (659 ) $ (799 ) Virginia Power Net deferred losses on derivatives-hedging activities, net of tax of $8 and $5 $ (12 ) $ (8 ) Net unrealized gains on nuclear decommissioning trust funds, net of tax of $(47) and $(35) 74 54 Total AOCI $ 62 $ 46 Dominion Energy Gas Net deferred losses on derivatives-hedging activities, net of tax of $15 and $15 $ (23 ) $ (24 ) Net unrecognized pension costs, net of tax of $59 and $68 (75 ) (99 ) Total AOCI $ (98 ) $ (123 ) D OMINION NERGY The following table presents Dominion Energy’s changes in AOCI by component, net of tax: Deferred gains and losses on derivatives- hedging activities Unrealized gains and losses on investment securities Unrecognized pension and other postretirement benefit costs Other comprehensive loss from equity method investees Total (millions) Year Ended December 31, 2017 Beginning balance $(280 ) $569 $(1,082 ) $(6 ) $(799 ) Other comprehensive income before reclassifications: gains (losses) 8 215 (69 ) 3 157 Amounts reclassified from AOCI: (gains) losses (1) (29 ) (37) 50 — (16 ) Net current period other comprehensive income (loss) (21 ) 178 (19 ) 3 141 Less other comprehensive income attributable to noncontrolling interest 1 — — — 1 Ending balance $(302 ) $747 $(1,101 ) $(3 ) $(659 ) Year Ended December 31, 2016 Beginning balance $(176 ) $504 $ (797 ) $(5 ) $(474 ) Other comprehensive income before reclassifications: gains (losses) 55 93 (319 ) (1 ) (172 ) Amounts reclassified from AOCI: (gains) losses (1) (159 ) (28) 34 — (153 ) Net current period other comprehensive income (loss) (104 ) 65 (285 ) (1 ) (325 ) Ending balance $(280 ) $569 $(1,082 ) $(6 ) $(799 ) (1) See table below for details about these reclassifications.
Reclassification out of Accumulated Other Comprehensive Income	The following table presents Dominion Energy’s reclassifications out of AOCI by component: Details about AOCI components Amounts reclassified from AOCI Affected line item in the Consolidated Statements of Income (millions) Year Ended December 31, 2017 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $ (81 ) Operating revenue 2 Purchased gas Interest rate contracts 52 Interest and related charges Foreign currency contracts (20 ) Other Income Total (47 ) Tax 18 Income tax expense Total, net of tax $ (29 ) Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $ (81 ) Other income Impairment 23 Other income Total (58 ) Tax 21 Income tax expense Total, net of tax $ (37 ) Unrecognized pension and other postretirement benefit costs: Amortization of prior-service costs (credits) $ (21 ) Other income Amortization of actuarial losses 103 Other income Total 82 Tax (32 ) Income tax expense Total, net of tax $ 50 Year Ended December 31, 2016 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $(330 ) Operating revenue 13 Purchased gas 10 Electric fuel and other Interest rate contracts 31 Interest and related charges Foreign currency contracts 17 Other Income Total (259 ) Tax 100 Income tax expense Total, net of tax $(159 ) Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $ (66 ) Other income Impairment 23 Other income Total (43 ) Tax 15 Income tax expense Total, net of tax $ (28 ) Unrecognized pension and other postretirement benefit costs: Prior-service costs (credits) $ (15 ) Other income Actuarial losses 71 Other income Total 56 Tax (22 ) Income tax expense Total, net of tax $ 34
Summary of restricted stock activity	The following table provides a summary of restricted stock activity for the years ended December 31, 2017, 2016 and 2015: Shares Weighted - average Grant Date Fair Value (thousands) Nonvested at December 31, 2014 1,065 $56.74 Granted 302 73.26 Vested (510 ) 50.71 Cancelled and forfeited (2 ) 62.62 Nonvested at December 31, 2015 855 $66.16 Granted 372 71.67 Vested (301 ) 56.83 Cancelled and forfeited (40 ) 71.75 Nonvested at December 31, 2016 886 $71.40 Granted 454 74.24 Vested (287 ) 68.90 Cancelled and forfeited (10 ) 72.37 Nonvested at December 31, 2017 1,043 $73.32
Virginia Electric and Power Company
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table presents Virginia Power’s changes in AOCI by component, net of tax: Deferred gains and losses on derivatives- hedging activities Unrealized gains and losses on investment securities Total (millions) Year Ended December 31, 2017 Beginning balance $ (8 ) $54 $46 Other comprehensive income before reclassifications: gains (losses) (5 ) 24 19 Amounts reclassified from AOCI: (gains) losses (1) 1 (4 ) (3 ) Net current period other comprehensive income (loss) (4 ) 20 16 Ending balance $(12) $74 $62 Year Ended December 31, 2016 Beginning balance $ (7 ) $47 $40 Other comprehensive income before reclassifications: gains (losses) (2 ) 11 9 Amounts reclassified from AOCI: (gains) losses (1) 1 (4 ) (3 ) Net current period other comprehensive income (loss) (1 ) 7 6 Ending balance $ (8 ) $54 $46 (1) See table below for details about these reclassifications.
Reclassification out of Accumulated Other Comprehensive Income	The following table presents Virginia Power’s reclassifications out of AOCI by component: Details about AOCI components Amounts reclassified from AOCI Affected line item in the Consolidated Statements of Income (millions) Year Ended December 31, 2017 (Gains) losses on cash flow hedges: Interest rate contracts $ 1 Interest and related charges Total 1 Tax — Income tax expense Total, net of tax $ 1 Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $(9 ) Other income Impairment 2 Other income Total (7 ) Tax 3 Income tax expense Total, net of tax $(4 ) Year Ended December 31, 2016 (Gains) losses on cash flow hedges: Interest rate contracts $ 1 Interest and related charges Total 1 Tax — Income tax expense Total, net of tax $ 1 Unrealized (gains) and losses on investment securities: Realized (gain) loss on sale of securities $(9 ) Other income Impairment 3 Other income Total (6 ) Tax 2 Income tax expense Total, net of tax $(4 )
Dominion Energy Gas Holdings, LLC
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table presents Dominion Energy Gas’ changes in AOCI by component, net of tax: Deferred gains and losses on derivatives- hedging activities Unrecognized pension costs Total (millions) Year Ended December 31, 2017 Beginning balance $(24 ) $(99 ) $(123 ) Other comprehensive income before reclassifications: gains (losses) 5 20 25 Amounts reclassified from AOCI (1) (4 ) 4 — Net current period other comprehensive income (loss) 1 24 25 Ending balance $(23 ) $(75 ) $ (98 ) Year Ended December 31, 2016 Beginning balance $(17 ) $(82 ) $ (99 ) Other comprehensive income before reclassifications: gains (losses) (16 ) (20 ) (36 ) Amounts reclassified from AOCI (1) 9 3 12 Net current period other comprehensive income (loss) (7 ) (17 ) (24 ) Ending balance $(24 ) $(99 ) $(123 ) (1) See table below for details about these reclassifications.
Reclassification out of Accumulated Other Comprehensive Income	The following table presents Dominion Energy Gas’ reclassifications out of AOCI by component: Details about AOCI components Amounts from AOCI Affected line item in the Consolidated Statements of Income (millions) Year Ended December 31, 2017 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $ 8 Operating revenue Interest rate contracts 5 Interest and related charges Foreign currency contracts (20 ) Other income Total (7) Tax 3 Income tax expense Total, net of tax $ (4 ) Unrecognized pension costs: Actuarial losses $ 6 Other income Total 6 Tax (2 ) Income tax expense Total, net of tax $ 4 Year Ended December 31, 2016 Deferred (gains) and losses on derivatives-hedging activities: Commodity contracts $ (4 ) Operating revenue Interest rate contracts 2 Interest and related charges Foreign currency contracts 17 Other income Total 15 Tax (6 ) Income tax expense Total, net of tax $ 9 Unrecognized pension costs: Actuarial losses $ 5 Other income Total 5 Tax (2 ) Income tax expense Total, net of tax $ 3

EMPLOYEE BENEFITPLANS (Tables)

EMPLOYEE BENEFITPLANS (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pension plan and other postretirement benefit plan obligations and plan assets and includes a statement of the plans funded status	The following table summarizes the changes in pension plan and other postretirement benefit plan obligations and plan assets and includes a statement of the plans’ funded status for Dominion Energy and Dominion Energy Gas (for employees represented by collective bargaining units): Pension Benefits Other Postretirement Benefits Year Ended December 31, 2017 2016 2017 2016 (millions, except percentages) Dominion Energy Changes in benefit obligation: Benefit obligation at beginning of year $ 8,132 $ 6,391 $ 1,478 $ 1,430 Dominion Energy Questar Combination — 817 — 85 Service cost 138 118 26 31 Interest cost 345 317 60 65 Benefits paid (323 ) (286 ) (83 ) (83 ) Actuarial (gains) losses during the year 830 784 119 166 Plan amendments (1) 5 — (73 ) (216 ) Settlements and curtailments (2) (75 ) (9 ) 2 — Benefit obligation at end of year $ 9,052 $ 8,132 $ 1,529 $ 1,478 Changes in fair value of plan assets: Fair value of plan assets at beginning of year $ 7,016 $ 6,166 $ 1,512 $ 1,382 Dominion Energy Questar Combination — 704 — 45 Actual return (loss) on plan assets 1,327 426 236 108 Employer contributions 118 15 13 12 Benefits paid (323 ) (286 ) (32 ) (35 ) Settlements (2) (76 ) (9 ) — — Fair value of plan assets at end of year $ 8,062 $ 7,016 $ 1,729 $ 1,512 Funded status at end of year $ (990 ) $ (1,116 ) $ 200 $ 34 Amounts recognized in the Consolidated Balance Sheets at December 31: Noncurrent pension and other postretirement benefit assets $ 1,117 $ 930 $ 261 $ 148 Other current liabilities (8 ) (43 ) — (5 ) Noncurrent pension and other postretirement benefit liabilities (2,099 ) (2,003 ) (61 ) (109 ) Net amount recognized $ (990 ) $ (1,116 ) $ 200 $ 34 Significant assumptions used to determine benefit obligations as of December 31: Discount rate 3.80%–3.81 % 3.31%–4.50 % 3.76% 3.92%–4.47 % Weighted average rate of increase for compensation 4.09 % 4.09 % 3.95%-4.11% 3.29 % Dominion Energy Gas Changes in benefit obligation: Benefit obligation at beginning of year $ 683 $ 608 $ 320 $ 292 Service cost 15 13 4 5 Interest cost 30 30 12 14 Benefits paid (33 ) (32 ) (19 ) (19 ) Actuarial (gains) losses during the year 78 64 34 28 Plan amendments (1) — — (61 ) — Benefit obligation at end of year $ 773 $ 683 $ 290 $ 320 Changes in fair value of plan assets: Fair value of plan assets at beginning of year $ 1,542 $ 1,467 $ 299 $ 283 Actual return (loss) on plan assets 294 107 41 23 Employer contributions — — 12 12 Benefits paid (33 ) (32 ) (19 ) (19 ) Fair value of plan assets at end of year $ 1,803 $ 1,542 $ 333 $ 299 Funded status at end of year $ 1,030 $ 859 $ 43 $ (21 ) Amounts recognized in the Consolidated Balance Sheets at December 31: Noncurrent pension and other postretirement benefit assets $ 1,030 $ 859 $ 57 $ — Noncurrent pension and other postretirement benefit liabilities (3) — — (14 ) (21 ) Net amount recognized $ 1,030 $ 859 $ 43 $ (21 ) Significant assumptions used to determine benefit obligations as of December 31: Discount rate 3.81 % 4.50 % 3.76 % 4.47 % Weighted average rate of increase for compensation 4.11 % 4.11 % n/a n/a (1) 2017 amounts relate primarily to a plan amendment that changed post-65 post-65 (2) 2017 amount relates primarily to settlement and curtailment as a result of the voluntary and involuntary separation programs at Dominion Energy Questar. 2016 amount relates primarily to a settlement for certain executives. (3) Reflected in other deferred credits and other liabilities in Dominion Energy Gas’ Consolidated Balance Sheets.
Benefit obligation in excess of plan asset	The following table provides information on the benefit obligations and fair value of plan assets for plans with a benefit obligation in excess of plan assets for Dominion Energy and Dominion Energy Gas (for employees represented by collective bargaining units): Pension Benefits Other Postretirement Benefits As of December 31, 2017 2016 2017 2016 (millions) Dominion Energy Benefit obligation $ 8,209 $ 7,386 $191 $470 Fair value of plan assets 6,103 5,340 156 356 Dominion Energy Gas Benefit obligation $ — $ — $157 $320 Fair value of plan assets — — 143 299
Accumulated benefit obligation in excess of plan assets	The following table provides information on the ABO and fair value of plan assets for Dominion Energy’s pension plans with an ABO in excess of plan assets: As of December 31, 2017 2016 (millions) Accumulated benefit obligation $ 7,392 $ 5,987 Fair value of plan assets 6,103 4,653
Benefit payments expected future service	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans: Estimated Future Benefit Payments Pension Benefits Other Postretirement Benefits (millions) Dominion Energy 2018 $373 $ 99 2019 378 101 2020 402 102 2021 418 102 2022 434 102 2023-2027 2,437 486 Dominion Energy Gas 2018 $ 35 $ 19 2019 37 19 2020 38 20 2021 39 20 2022 41 20 2023-2027 214 94
Fair values of pension and post retirement plan assets by asset category	The fair values of Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) pension plan assets by asset category are as follows: At December 31, 2017 2016 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (millions) Dominion Energy Cash and cash equivalents $ 18 $ — $— $ 18 $ 12 $ 2 $— $ 14 Common and preferred stocks: U.S. 1,902 — — 1,902 1,705 — — 1,705 International 1,151 — — 1,151 928 — — 928 Insurance contracts — 352 — 352 — 334 — 334 Corporate debt instruments 41 729 — 770 35 682 — 717 Government securities 9 676 — 685 13 522 — 535 Total recorded at fair value $ 3,121 $ 1,757 $— $ 4,878 $ 2,693 $ 1,540 $— $ 4,233 Assets recorded at NAV (1) Common/collective trust funds 2,272 1,960 Alternative investments: Real estate funds 111 121 Private equity funds 606 506 Debt funds 161 153 Hedge funds 19 25 Total recorded at NAV $ 3,169 $ 2,765 Total investments (2) $ 8,047 $ 6,998 Dominion Energy Gas Cash and cash equivalents $ 4 $ — $— $ 4 $ 3 $ — $— $ 3 Common and preferred stocks: U.S. 425 — — 425 375 — — 375 International 257 — — 257 203 — — 203 Insurance contracts — 79 — 79 — 73 — 73 Corporate debt instruments 9 163 — 172 8 150 — 158 Government securities 2 151 — 153 3 115 — 118 Total recorded at fair value $ 697 $ 393 $— $ 1,090 $ 592 $ 338 $— $ 930 Assets recorded at NAV (1) Common/collective trust funds 509 430 Alternative investments: Real estate funds 25 27 Private equity funds 135 111 Debt funds 36 34 Hedge funds 4 6 Total recorded at NAV $ 709 $ 608 Total investments (3) $ 1,799 $ 1,538 (1) These investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy. (2) Excludes net assets related to pending sales of securities of $11 million, net accrued income of $19 million, and includes net assets related to pending purchases of securities of $15 million at December 31, 2017. Excludes net assets related to pending sales of securities of $46 million, net accrued income of $19 million, and includes net assets related to pending purchases of securities of $47 million at December 31, 2016. (3) Excludes net assets related to pending sales of securities of $3 million, net accrued income of $4 million, and includes net assets related to pending purchases of securities of $3 million at December 31, 2017. Excludes net assets related to pending sales of securities of $10 million, net accrued income of $4 million, and includes net assets related to pending purchases of securities of $10 million at December 31, 2016. The fair values of Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) other postretirement plan assets by asset category are as follows: At December 31, 2017 2016 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (millions) Dominion Energy Cash and cash equivalents $ 1 $ 2 $— $ 3 $ 1 $ 1 $— $ 2 Common and preferred stocks: U.S. 636 — — 636 571 — — 571 International 196 — — 196 143 — — 143 Insurance contracts — 21 — 21 — 19 — 19 Corporate debt instruments 2 44 — 46 2 40 — 42 Government securities 1 41 — 42 1 30 — 31 Total recorded at fair value $836 $108 $— $ 944 $718 $90 $— $ 808 Assets recorded at NAV (1) Common/collective trust funds 689 621 Alternative investments: Real estate funds 9 9 Private equity funds 73 59 Debt funds 11 12 Hedge funds 1 1 Total recorded at NAV $ 783 $ 702 Total investments (2) $ 1,727 $1,510 Dominion Energy Gas Common and preferred stocks: U.S. $130 $ — $— $ 130 $121 $— $— $ 121 International 33 — — 33 24 — — 24 Total recorded at fair value $163 $ — $— $ 163 $145 $— $— $ 145 Assets recorded at NAV (1) Common/collective trust funds 154 140 Alternative investments: Real estate funds 1 1 Private equity funds 15 12 Debt funds — 1 Total recorded at NAV $ 170 $ 154 Total investments $ 333 $ 299 (1) These investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy. (2) Excludes net assets related to pending sales of securities of $1 million, net accrued income of $2 million, and includes net assets related to pending purchases of securities of $1 million at December 31, 2017. Excludes net assets related to pending sales of securities of $5 million, net accrued income of $2 million, and includes net assets related to pending purchases of securities of $5 million at December 31, 2016.
Net periodic benefit (credit) cost and amounts recognized in other comprehensive income and regulatory assets and liabilities	The components of the provision for net periodic benefit (credit) cost and amounts recognized in other comprehensive income and regulatory assets and liabilities for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans are as follows: Pension Benefits Other Postretirement Benefits Year Ended December 31, 2017 2016 2015 2017 2016 2015 (millions, except percentages) Dominion Energy Service cost $ 138 $ 118 $ 126 $ 26 $ 31 $ 40 Interest cost 345 317 287 60 65 67 Expected return on plan assets (639 ) (573 ) (531 ) (128 ) (118 ) (117 ) Amortization of prior service (credit) cost 1 1 2 (51 ) (35 ) (27 ) Amortization of net actuarial loss 162 111 160 13 8 6 Settlements and curtailments — 1 — — — — Net periodic benefit (credit) cost $ 7 $ (25 ) $ 44 $ (80 ) $ (49 ) $ (31 ) Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities: Current year net actuarial (gain) loss $ 142 $ 931 $ 159 $ 12 $ 178 $ (18 ) Prior service (credit) cost 5 — — (73 ) (216 ) (31 ) Settlements and curtailments 1 (1 ) — 2 — — Less amounts included in net periodic benefit cost: Amortization of net actuarial loss (162 ) (111 ) (160 ) (13 ) (8 ) (6 ) Amortization of prior service credit (cost) (1 ) (1 ) (2 ) 51 35 27 Total recognized in other comprehensive income and regulatory assets and liabilities $ (15 ) $ 818 $ (3 ) $ (21 ) $ (11 ) $ (28 ) Significant assumptions used to determine periodic cost: Discount rate 3.31%-4.50 % 2.87%-4.99 % 4.40 % 3.92%-4.47 % 3.56%-4.94 % 4.40 % Expected long-term rate of return on plan assets 8.75 % 8.75 % 8.75 % 8.50 % 8.50 % 8.50 % Weighted average rate of increase for compensation 4.09 % 4.22 % 4.22 % 3.29 % 4.22 % 4.22 % Healthcare cost trend rate (1) 7.00 % 7.00 % 7.00 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) (1) 5.00 % 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate (1)(2) 2021 2020 2019 Dominion Energy Gas Service cost $ 15 $ 13 $ 15 $ 4 $ 5 $ 7 Interest cost 30 30 27 12 14 14 Expected return on plan assets (141 ) (134 ) (126 ) (24 ) (23 ) (24 ) Amortization of prior service (credit) cost — — 1 (3 ) 1 (1 ) Amortization of net actuarial loss 16 13 20 2 1 2 Net periodic benefit (credit) cost $ (80 ) $ (78 ) $ (63 ) $ (9 ) $ (2 ) $ (2 ) Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities: Current year net actuarial (gain) loss $ (75 ) $ 91 $ 97 $ 18 $ 28 $ (9 ) Prior service cost — — — (61 ) — — Less amounts included in net periodic benefit cost: Amortization of net actuarial loss (16 ) (13 ) (20 ) (2 ) (1 ) (2 ) Amortization of prior service credit (cost) — — (1 ) 3 (1 ) 1 Total recognized in other comprehensive income and regulatory assets and liabilities $ (91 ) $ 78 $ 76 $ (42 ) $ 26 $ (10 ) Significant assumptions used to determine periodic cost: Discount rate 4.50 % 4.99 % 4.40 % 4.47 % 4.93 % 4.40 % Expected long-term rate of return on plan assets 8.75 % 8.75 % 8.75 % 8.50 % 8.50 % 8.50 % Weighted average rate of increase for compensation 4.11 % 3.93 % 3.93 % 4.11 % 3.93 % 3.93 % Healthcare cost trend rate (1) 7.00 % 7.00 % 7.00 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) (1) 5.00 % 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate (1)(2) 2021 2020 2019 (1) Assumptions used to determine net periodic cost for the following year. (2) The Society of Actuaries model used to determine healthcare cost trend rates was updated in 2014. The new model converges to the ultimate trend rate much more quickly than previous models.
Components of AOCI and regulatory assets and liabilities that have not been recognized as components of periodic benefit (credit) cost	The components of AOCI and regulatory assets and liabilities for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans that have not been recognized as components of net periodic benefit (credit) cost are as follows: Pension Benefits Other Postretirement Benefits At December 31, 2017 2016 2017 2016 (millions) Dominion Energy Net actuarial loss $ 3,181 $ 3,200 $ 283 $ 283 Prior service (credit) cost 8 4 (440 ) (419 ) Total (1) $ 3,189 $ 3,204 $ (157 ) $ (136 ) Dominion Energy Gas Net actuarial loss $ 367 $ 458 $ 76 $ 60 Prior service (credit) cost — — (52 ) 7 Total (2) $ 367 $ 458 $ 24 $ 67 (1) As of December 31, 2017, of the $3.2 billion and $(157) million related to pension benefits and other postretirement benefits, $1.9 billion and $(87) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities. As of December 31, 2016, of the $3.2 billion and $(136) million related to pension benefits and other postretirement benefits, $1.9 billion and $(103) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities. (2) As of December 31, 2017, of the $367 million related to pension benefits, $134 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $24 million related to other postretirement benefits is included entirely in regulatory assets and liabilities. As of December 31, 2016, of the $458 million related to pension benefits, $167 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $67 million related to other postretirement benefits is included entirely in regulatory assets and liabilities.
Components of AOCI and regulatory assets and liabilities that are expected to be amortized as components of periodic benefit cost in 2017	The following table provides the components of AOCI and regulatory assets and liabilities for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) plans as of December 31, 2017 that are expected to be amortized as components of net periodic benefit (credit) cost in 2018: Pension Benefits Other Benefits (millions) Dominion Energy Net actuarial loss $193 $ 11 Prior service (credit) cost 1 (52 ) Dominion Energy Gas Net actuarial loss $ 19 $ 3 Prior service (credit) cost — (4 )
Effect of one percentage point change on benefit plans	A one percentage point change in assumed healthcare cost trend rates would have had the following effects for Dominion Energy’s and Dominion Energy Gas’ (for employees represented by collective bargaining units) other postretirement benefit plans: Other Postretirement Benefits One percentage point increase One percentage point decrease (millions) Dominion Energy Effect on net periodic cost for 2018 $ 24 $ (15 ) Effect on other postretirement benefit obligation at December 31, 2017 158 (132 ) Dominion Energy Gas Effect on net periodic cost for 2018 $ 4 $ (3 ) Effect on other postretirement benefit obligation at December 31, 2017 31 (26 )

COMMITMENTS ANDCONTINGENCIES (T

COMMITMENTS ANDCONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2017
Nuclear Insurance	The current levels of nuclear property insurance coverage for Dominion Energy’s and Virginia Power’s nuclear units are as follows: Coverage (billions) Dominion Energy Millstone $1.70 Kewaunee 1.06 Virginia Power (1) Surry $1.70 North Anna 1.70 (1) Surry and North Anna share a blanket property limit of $200 million.
Lease Commitments	Future minimum lease payments under noncancelable operating and capital leases that have initial or remaining lease terms in excess of one year as of December 31, 2017 are as follows: 2018 2019 2020 2021 2022 Thereafter Total (millions) Dominion Energy (1) $ 68 $ 63 $ 56 $ 48 $ 39 $361 $ 635 Virginia Power $ 34 $ 31 $ 27 $ 22 $ 15 $ 28 $ 157 Dominion Energy Gas $ 15 $ 13 $ 10 $ 9 $ 7 $ 41 $ 95 (1) Amounts include a lease agreement for the Dominion Energy Questar corporate office, which is accounted for as a capital lease. At December 31, 2017 and 2016, the Consolidated Balance Sheets include $27 million and $30 million, respectively, in property, plant and equipment and $33 million and $35 million, respectively, in other deferred credits and other liabilities. The Consolidated Statements of Income include $3 million and less than $1 million recorded in depreciation, depletion and amortization for the years ended December 31, 2017 and 2016.
Schedule Of Subsidiary Guarantees	At December 31, 2017, Dominion Energy had issued the following subsidiary guarantees: Maximum Exposure (millions) Commodity transactions (1) $2,027 Nuclear obligations (2) 227 Cove Point (3) 1,900 Solar (4) 1,064 Other (5) 553 Total (6) $5,771 (1) Guarantees related to commodity commitments of certain subsidiaries. These guarantees were provided to counterparties in order to facilitate physical and financial transaction related commodities and services. (2) Guarantees related to certain DGI subsidiaries’ regarding all aspects of running a nuclear facility. (3) Guarantees related to Cove Point, in support of terminal services, transportation and construction. Cove Point has two guarantees that have no maximum limit and, therefore, are not included in this amount. (4) Includes guarantees to facilitate the development of solar projects. Also includes guarantees entered into by DGI on behalf of certain subsidiaries to facilitate the acquisition and development of solar projects. (5) Guarantees related to other miscellaneous contractual obligations such as leases, environmental obligations, construction projects and insurance programs. Due to the uncertainty of worker’s compensation claims, the parental guarantee has no stated limit. Also included are guarantees related to certain DGI subsidiaries’ obligations for equity capital contributions and energy generation associated with Fowler Ridge and NedPower. As of December 31, 2017, Dominion Energy’s maximum remaining cumulative exposure under these equity funding agreements is $17 million through 2019 and its maximum annual future contributions could range from approximately $4 million to $14 million. (6) Excludes Dominion Energy’s guarantee for the construction of the new corporate office property discussed further within Lease Commitments above.
Virginia Electric and Power Company
Long-term Purchase Commitment	At December 31, 2017, Virginia Power had the following long-term commitments that are noncancelable or are cancelable only under certain conditions, and that a third party has used to secure financing for the facility that will provide the contracted goods or services: 2018 2019 2020 2021 2022 Thereafter Total (millions) Purchased electric capacity (1) $ 93 $ 61 $ 52 $ 46 $— $— $ 252 (1) Commitments represent estimated amounts payable for capacity under a power purchase contract with a qualifying facility and an independent power producer, which ends in 2021. Capacity payments under the contract are generally based on fixed dollar amounts per month, subject to escalation using broad-based economic indices. At December 31, 2017, the present value of Virginia Power’s total commitment for capacity payments is $221 million. Capacity payments totaled $114 million, $248 million, and $305 million, and energy payments totaled $72 million, $126 million, and $198 million for the years ended 2017, 2016 and 2015, respectively.

RELATED-PARTYTRANSACTIONS (Tabl

RELATED-PARTYTRANSACTIONS (Tables)	12 Months Ended
	Dec. 31, 2017
Virginia Electric and Power Company
Schedule of Related Party Transactions	Presented below are significant transactions with DES and other affiliates: Year Ended December 31, 2017 2016 2015 (millions) Commodity purchases from affiliates $ 674 $ 571 $ 555 Services provided by affiliates (1) 453 454 422 Services provided to affiliates 25 22 22 (1) Includes capitalized expenditures of $144 million, $144 million and $143 million for the year ended December 31, 2017, 2016 and 2015, respectively.
Dominion Energy Gas Holdings, LLC
Schedule of Related Party Transactions	Management believes the assumptions and methodologies underlying the allocation of general corporate overhead expenses are reasonable. The costs of these services follow: Year Ended December 31, 2017 2016 2015 (millions) Purchases of natural gas and transportation and storage services from affiliates $ 5 $ 9 $ 10 Sales of natural gas and transportation and storage services to affiliates 70 69 69 Services provided by related parties (1) 143 141 133 Services provided to related parties (2) 156 128 101 (1) Includes capitalized expenditures of $45 million, $49 million and $57 million for the year ended December 31, 2017, 2016 and 2015, respectively. (2) Amounts primarily attributable to Atlantic Coast Pipeline. The following table presents affiliated and related party balances reflected in Dominion Energy Gas’ Consolidated Balance Sheets: At December 31, 2017 2016 (millions) Other receivables (1) $ 12 $ 10 Customer receivables from related parties 1 1 Imbalances receivable from affiliates 1 2 Imbalances payable to affiliates (2) — 4 Affiliated notes receivable (3) 20 18 (1) Represents amounts due from Atlantic Coast Pipeline, a related party VIE. (2) Amounts are presented in other current liabilities in Dominion Energy Gas’ Consolidated Balance Sheets. (3) Amounts are presented in other deferred charges and other assets in Dominion Energy Gas’ Consolidated Balance Sheets.

OPERATING SEGMENTS (Tables)

OPERATING SEGMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting Disclosure Other Information	A description of the operations included in the Companies’ primary operating segments is as follows: Primary Operating Description of Operations Dominion Virginia Dominion Power Delivery Regulated electric distribution X X Regulated electric transmission X X Power Generation Regulated electric fleet X X Merchant electric fleet X Gas Infrastructure Gas transmission and storage X (1) X Gas distribution and storage X X Gas gathering and processing X X LNG terminalling and storage X Nonregulated retail energy marketing X (1) Includes remaining producer services activities.
Schedule of Segment Reporting Information, by Segment	The following table presents segment information pertaining to Dominion Energy’s operations: Year Ended December 31, Power Power Gas Corporate and Other Adjustments & Eliminations Consolidated Total (millions) 2017 Total revenue from external customers $2,206 $6,676 $2,832 $ 16 $ 856 $12,586 Intersegment revenue 22 10 834 610 (1,476 ) — Total operating revenue 2,228 6,686 3,666 626 (620 ) 12,586 Depreciation, depletion and amortization 593 747 522 43 — 1,905 Equity in earnings of equity method investees — (181) 159 4 — (18 ) Interest income 4 92 45 96 (155 ) 82 Interest and related charges 265 342 109 644 (155 ) 1,205 Income tax expense (benefit) 334 373 487 (1,224 ) — (30 ) Net income attributable to Dominion Energy 531 1,181 898 389 — 2,999 Investment in equity method investees — 81 1,422 41 — 1,544 Capital expenditures 1,433 2,275 2,149 52 — 5,909 Total assets (billions) 16.7 29.0 28.0 12.0 (9.1 ) 76.6 2016 Total revenue from external customers $2,210 $6,747 $2,069 $ (7 ) $ 718 $11,737 Intersegment revenue 23 10 697 609 (1,339 ) — Total operating revenue 2,233 6,757 2,766 602 (621 ) 11,737 Depreciation, depletion and amortization 537 662 330 30 — 1,559 Equity in earnings of equity method investees — (16) 105 22 — 111 Interest income — 74 34 36 (78 ) 66 Interest and related charges 244 290 38 516 (78 ) 1,010 Income tax expense (benefit) 308 279 431 (363 ) — 655 Net income (loss) attributable to Dominion Energy 484 1,397 726 (484 ) — 2,123 Investment in equity method investees — 228 1,289 44 — 1,561 Capital expenditures 1,320 2,440 2,322 43 — 6,125 Total assets (billions) 15.6 27.1 26.0 10.2 (7.3 ) 71.6 2015 Total revenue from external customers $2,091 $7,001 $1,877 $ (27) $ 741 $11,683 Intersegment revenue 20 15 695 554 (1,284 ) — Total operating revenue 2,111 7,016 2,572 527 (543 ) 11,683 Depreciation, depletion and amortization 498 591 262 44 — 1,395 Equity in earnings of equity method investees — (15 ) 60 11 — 56 Interest income — 64 25 13 (44 ) 58 Interest and related charges 230 262 27 429 (44 ) 904 Income tax expense (benefit) 307 465 423 (290 ) — 905 Net income (loss) attributable to Dominion Energy 490 1,120 680 (391 ) — 1,899 Investment in equity method investees — 245 1,042 33 — 1,320 Capital expenditures 1,607 2,190 2,153 43 — 5,993
Virginia Electric and Power Company
Schedule of Segment Reporting Information, by Segment	The following table presents segment information pertaining to Virginia Power’s operations: Year Ended December 31, Power Power Corporate and Other Adjustments & Eliminations Consolidated Total (millions) 2017 Operating revenue $2,212 $5,344 $ — $ — $7,556 Depreciation and amortization 594 547 — — 1,141 Interest income 4 15 3 (3 ) 19 Interest and related charges 265 232 — (3 ) 494 Income tax expense (benefit) 334 534 (94 ) — 774 Net income 527 939 74 — 1,540 Capital expenditures 1,439 1,290 — — 2,729 Total assets (billions) 16.6 18.6 — (0.1 ) 35.1 2016 Operating revenue $2,217 $5,390 $ (19 ) $ — $7,588 Depreciation and amortization 537 488 — — 1,025 Interest income — — — — — Interest and related charges 244 219 — (2 ) 461 Income tax expense (benefit) 307 524 (104 ) — 727 Net income (loss) 482 909 (173 ) — 1,218 Capital expenditures 1,313 1,336 — — 2,649 Total assets (billions) 15.6 17.8 — (0.1 ) 33.3 2015 Operating revenue $2,099 $5,566 $ (43 ) $ — $7,622 Depreciation and amortization 498 453 2 — 953 Interest income — 7 — — 7 Interest and related charges 230 210 4 (1 ) 443 Income tax expense (benefit) 308 437 (86 ) — 659 Net income (loss) 490 750 (153 ) — 1,087 Capital expenditures 1,569 1,120 — — 2,689
Dominion Energy Gas Holdings, LLC
Schedule of Segment Reporting Information, by Segment	The following table presents segment information pertaining to Dominion Energy Gas’ operations: Year Ended December 31, Gas Infrastructure Corporate and Consolidated Total (millions) 2017 Operating revenue $1,814 $ — $1,814 Depreciation and amortization 227 — 227 Equity in earnings of equity method investees 21 — 21 Interest income 2 — 2 Interest and related charges 97 — 97 Income tax expense (benefit) 256 (205 ) 51 Net income 436 179 615 Investment in equity method investees 95 — 95 Capital expenditures 778 — 778 Total assets (billions) 11.3 0.6 11.9 2016 Operating revenue $1,638 $ — $1,638 Depreciation and amortization 214 (10 ) 204 Equity in earnings of equity method investees 21 — 21 Interest income 1 — 1 Interest and related charges 92 2 94 Income tax expense (benefit) 237 (22 ) 215 Net income (loss) 395 (3 ) 392 Investment in equity method investees 98 — 98 Capital expenditures 854 — 854 Total assets (billions) 10.5 0.6 11.1 2015 Operating revenue $1,716 $ — $1,716 Depreciation and amortization 213 4 217 Equity in earnings of equity method investees 23 — 23 Interest income 1 — 1 Interest and related charges 72 1 73 Income tax expense (benefit) 296 (13 ) 283 Net income (loss) 478 (21 ) 457 Investment in equity method investees 102 — 102 Capital expenditures 795 — 795

QUARTERLY FINANCIALAND COMMON55

QUARTERLY FINANCIALAND COMMON STOCKDATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial and Common Stock Data	A summary of the Companies’ quarterly results of operations for the years ended December 31, 2017 and 2016 follows. Amounts reflect all adjustments necessary in the opinion of management for a fair statement of the results for the interim periods. Results for interim periods may fluctuate as a result of weather conditions, changes in rates and other factors. D OMINION NERGY First Quarter Second Quarter Third Quarter Fourth Quarter (millions, except per share amounts) 2017 Operating revenue $ 3,384 $ 2,813 $ 3,179 $ 3,210 Income from operations 1,079 753 1,152 953 Net income including noncontrolling interests 674 417 696 1,333 Net income attributable to Dominion Energy 632 390 665 1,312 Basic EPS: Net income attributable to Dominion Energy 1.01 0.62 1.03 2.04 Diluted EPS: Net income attributable to Dominion Energy 1.01 0.62 1.03 2.04 Dividends declared per share 0.755 0.755 0.770 0.770 Common stock prices (intraday high-low) $ 79.36 - 70.87 $ 81.65 - 76.17 $ 80.67 - 75.40 $ 85.30 - 75.75 2016 Operating revenue $ 2,921 $ 2,598 $ 3,132 $ 3,086 Income from operations 841 740 1,102 765 Net income including noncontrolling interests 531 462 728 491 Net income attributable to Dominion Energy 524 452 690 457 Basic EPS: Net income attributable to Dominion Energy 0.88 0.73 1.10 0.73 Diluted EPS: Net income attributable to Dominion Energy 0.88 0.73 1.10 0.73 Dividends declared per share 0.700 0.700 0.700 0.700 Common stock prices (intraday high-low) $ 75.18 - 66.25 $ 77.93 - 68.71 $ 78.97 - 72.49 $ 77.32 - 69.51
Virginia Electric and Power Company
Quarterly Financial and Common Stock Data	Virginia Power’s quarterly results of operations were as follows: First Quarter Second Quarter Third Quarter Fourth Quarter (millions) 2017 Operating revenue $ 1,831 $ 1,747 $ 2,154 $ 1,824 Income from operations 653 613 847 619 Net income 356 318 459 407 2016 Operating revenue $ 1,890 $ 1,776 $ 2,211 $ 1,711 Income from operations 514 553 914 369 Net income 263 280 503 172
Dominion Energy Gas Holdings, LLC
Quarterly Financial and Common Stock Data	Dominion Energy Gas’ quarterly results of operations were as follows: First Quarter Second Quarter Third Quarter Fourth Quarter (millions) 2017 Operating revenue $490 $422 $401 $501 Income from operations 156 116 185 182 Net income 108 77 117 313 2016 Operating revenue $431 $368 $382 $457 Income from operations 156 167 114 156 Net income 98 105 83 106

Nature of Operations (Narrative

Nature of Operations (Narrative) (Detail)	1 Months Ended		12 Months Ended
	Sep. 30, 2015shares	Oct. 31, 2014shares	Dec. 31, 2017Segments
Subsidiary, Sale of Stock [Line Items]
Number of operating segments			3
Dominion Energy Midstream Partners, LP | Iroquois | Partnership Interest
Subsidiary, Sale of Stock [Line Items]
Common units included in initial public offering | shares	8,600,000
Noncontrolling partnership percentage interest			25.93%
Dominion Energy Midstream Partners, LP | Common and Subordinated Units
Subsidiary, Sale of Stock [Line Items]
Ownership interest percentage of limited partner interests			50.60%
Dominion Energy Midstream Partners, LP | Convertible Preferred Units
Subsidiary, Sale of Stock [Line Items]
Ownership interest percentage of limited partner interests			37.50%
Dominion Energy Midstream Partners, LP | IPO [Member]
Subsidiary, Sale of Stock [Line Items]
Common units included in initial public offering | shares		20,125,000
Virginia Electric and Power Company
Subsidiary, Sale of Stock [Line Items]
Number of operating segments			2
Dominion Energy Gas Holdings, LLC
Subsidiary, Sale of Stock [Line Items]
Number of operating segments			1

Significant Accounting Polici57

Significant Accounting Policies (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Significant Accounting Policies [Line Items]
Accrued unbilled revenue		$ 661	$ 631
Percentage of fuel currently subject to deferred fuel accounting		84.00%
Federal statutory income tax rate		35.00%	35.00%	35.00%
Recognized interest income		$ 11
Margin deposit assets		92	$ 82
Capitalized interest costs and AFUDC		236	159	$ 100
Unrealized gains reclassified from AOCI to retained earnings		1,100
Unrealized gains reclassified from AOCI to retained earnings after-tax		734
Net unrealized gains on equity securities previously classified as cost method investments		36
Net unrealized gains on equity securities previously classified as cost method investments, after tax		22
Net unrealized gains in other income		275
Net unrealized gains in other income, after tax		176
Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings		165
Change in Estimated Useful Life | Merchant generation assets
Significant Accounting Policies [Line Items]
Increase (decrease) in depreciation expense		26
Increase (decrease) in depreciation expense, after tax		$ 16
NRG Energy, Inc | Four Brothers and Three Cedars | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Significant Accounting Policies [Line Items]
Percentage of equity interest sold to noncontrolling interest owners		33.00%
Virginia Electric and Power Company
Significant Accounting Policies [Line Items]
Accrued unbilled revenue		$ 400	$ 349
Federal statutory income tax rate		35.00%	35.00%	35.00%
Recognized interest income		$ 11
Noncurrent income taxes receivable		1
Margin deposit assets		23	$ 2
Capitalized interest costs		37	21	$ 30
AFUDC related to projects		22	31	$ 19
Unrealized gains reclassified from AOCI to retained earnings		119
Unrealized gains reclassified from AOCI to retained earnings after-tax		73
Net unrealized gains on equity securities previously classified as cost method investments		36
Net unrealized gains on equity securities previously classified as cost method investments, after tax		22
Net unrealized gains in other income		30
Net unrealized gains in other income, after tax		19
Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings		13
Virginia Electric and Power Company | Change in Depreciation Rates from New Depreciation Study
Significant Accounting Policies [Line Items]
Increase (decrease) in depreciation expense		40
Increase (decrease) in depreciation expense, after tax		25
Virginia Electric and Power Company | Federal
Significant Accounting Policies [Line Items]
Noncurrent income taxes receivable		1
Noncurrent income tax payable			2
Virginia Electric and Power Company | State
Significant Accounting Policies [Line Items]
Noncurrent income taxes receivable			13
Income tax receivable			6
Virginia Electric and Power Company | Affiliated Entity
Significant Accounting Policies [Line Items]
Income tax payable		16
Income tax receivable			112
Virginia Electric and Power Company | Affiliated Entity | Federal
Significant Accounting Policies [Line Items]
Income tax payable		16
Income tax receivable			122
Virginia Electric and Power Company | Affiliated Entity | State
Significant Accounting Policies [Line Items]
Affiliated payables for estimated income taxes owed			10
Dominion Energy Gas Holdings, LLC
Significant Accounting Policies [Line Items]
Accrued unbilled revenue		$ 121	$ 134
Federal statutory income tax rate		35.00%	35.00%	35.00%
Capitalized interest costs		$ 25	$ 8	$ 1
Inventory under LIFO method		9	13
Amount exceeded on LIFO basis		79	55
Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings		26
Dominion Energy Gas Holdings, LLC | Federal
Significant Accounting Policies [Line Items]
Noncurrent income tax payable			1
Dominion Energy Gas Holdings, LLC | State
Significant Accounting Policies [Line Items]
Noncurrent income taxes receivable		14
Income tax receivable			1
Noncurrent income tax payable			7
Dominion Energy Gas Holdings, LLC | Affiliated Entity
Significant Accounting Policies [Line Items]
Income tax payable		25
Income tax receivable			11
Dominion Energy Gas Holdings, LLC | Affiliated Entity | Federal
Significant Accounting Policies [Line Items]
Income tax payable		21
Income tax receivable			10
Dominion Energy Gas Holdings, LLC | Affiliated Entity | State
Significant Accounting Policies [Line Items]
Income tax payable		4
Income tax receivable			$ 1
Scenario, Forecast
Significant Accounting Policies [Line Items]
Federal statutory income tax rate	21.00%
Retained Earnings
Significant Accounting Policies [Line Items]
Net unrealized gains on equity securities previously classified as cost method investments		4
Retained Earnings | Virginia Electric and Power Company
Significant Accounting Policies [Line Items]
Net unrealized gains on equity securities previously classified as cost method investments		4
Accounting Standards Update 2017-05 [Member] | Cumulative Effect Of Changes In Accounting Principle [Member]
Significant Accounting Policies [Line Items]
Change in accounting principle to reclassify from noncontrolling interests		127
Current Regulatory Liabilities [Member]
Significant Accounting Policies [Line Items]
Net unrealized gains on equity securities previously classified as cost method investments		32
Current Regulatory Liabilities [Member] | Virginia Electric and Power Company
Significant Accounting Policies [Line Items]
Net unrealized gains on equity securities previously classified as cost method investments		$ 32
Maximum | Nonutility Gas Gathering and Processing
Significant Accounting Policies [Line Items]
Estimated Useful Lives		50 years
Maximum | Virginia Electric and Power Company | State
Significant Accounting Policies [Line Items]
Noncurrent income taxes receivable		$ 1
Maximum | Dominion Energy Gas Holdings, LLC | Nonutility Gas Gathering and Processing
Significant Accounting Policies [Line Items]
Estimated Useful Lives		50 years
Minimum | Nonutility Gas Gathering and Processing
Significant Accounting Policies [Line Items]
Estimated Useful Lives		3 years
Minimum | Dominion Energy Gas Holdings, LLC | Nonutility Gas Gathering and Processing
Significant Accounting Policies [Line Items]
Estimated Useful Lives		10 years

Significant Accounting Polici58

Significant Accounting Policies (Checks the Outstanding Accounts Payable but not yet Presented for Payment and Recorded) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts Payable [Line Items]
Accounts payable for checks outstanding	$ 30	$ 24
Virginia Electric and Power Company
Accounts Payable [Line Items]
Accounts payable for checks outstanding	17	11
Dominion Energy Gas Holdings, LLC
Accounts Payable [Line Items]
Accounts payable for checks outstanding	$ 7	$ 9

Significant Accounting Polici59

Significant Accounting Policies (Other Cash Provided By (Used In) Investing Activities) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Cash Provided By (Used In) Investing Activities [Line Items]
Other cash provided by (used in) investing activities	$ 33	$ 83	$ (65)
Virginia Electric and Power Company
Other Cash Provided By (Used In) Investing Activities [Line Items]
Other cash provided by (used in) investing activities	(41)	(33)	(87)
Dominion Energy Gas Holdings, LLC
Other Cash Provided By (Used In) Investing Activities [Line Items]
Other cash provided by (used in) investing activities	(19)	(12)	(17)
Scenario, Previously Reported
Other Cash Provided By (Used In) Investing Activities [Line Items]
Other cash provided by (used in) investing activities	29	47	(71)
Scenario, Previously Reported | Virginia Electric and Power Company
Other Cash Provided By (Used In) Investing Activities [Line Items]
Other cash provided by (used in) investing activities	(51)	(33)	(87)
Scenario, Previously Reported | Dominion Energy Gas Holdings, LLC
Other Cash Provided By (Used In) Investing Activities [Line Items]
Other cash provided by (used in) investing activities	$ (23)	$ (18)	$ (11)

Significant Accounting Polici60

Significant Accounting Policies (Other Adjustments from Operating Activities) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Adjustments from Operating Activities [Line Items]
Other adjustments from operating activities	$ (84)	$ (84)	$ (26)
Dominion Energy Gas Holdings, LLC
Other Adjustments from Operating Activities [Line Items]
Other adjustments from operating activities	(7)	(6)	23
Scenario, Previously Reported
Other Adjustments from Operating Activities [Line Items]
Other adjustments from operating activities	(37)	(108)	(42)
Scenario, Previously Reported | Dominion Energy Gas Holdings, LLC
Other Adjustments from Operating Activities [Line Items]
Other adjustments from operating activities	$ (9)	$ (6)	$ 16

Significant Accounting Polici61

Significant Accounting Policies (Reconciliation of Total Cash, Restricted Cash and Equivalents) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash, Cash Equivalents and Restricted Cash [Line Items]
Cash and cash equivalents	$ 120	$ 261	$ 607	$ 318
Restricted cash and equivalents	65	61	25	19
Cash, restricted cash and equivalents	185	322	632	337
Virginia Electric and Power Company
Cash, Cash Equivalents and Restricted Cash [Line Items]
Cash and cash equivalents	14	11	18	15
Restricted cash and equivalents	10
Cash, restricted cash and equivalents	24	11	18	15
Dominion Energy Gas Holdings, LLC
Cash, Cash Equivalents and Restricted Cash [Line Items]
Cash and cash equivalents	4	23	13	9
Restricted cash and equivalents	26	20	14	13
Cash, restricted cash and equivalents	$ 30	$ 43	$ 27	$ 22

Significant Accounting Polici62

Significant Accounting Policies (Depreciation Rates and Estimated Useful Life) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Generation
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.94%	2.83%	2.78%
Generation | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.94%	2.83%	2.78%
Transmission
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.55%	2.47%	2.42%
Transmission | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.54%	2.36%	2.33%
Transmission | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.40%	2.43%	2.46%
Distribution
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	3.00%	3.02%	3.11%
Distribution | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	3.32%	3.32%	3.33%
Storage
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.48%	2.29%	2.42%
Storage | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.45%	2.19%	2.44%
Gas Gathering and Processing
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.21%	2.66%	3.19%
Gas Gathering and Processing | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.42%	2.58%	3.20%
General and Other
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	4.89%	4.12%	3.67%
General and Other | Virginia Electric and Power Company
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	4.68%	3.49%	3.40%
General and Other | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	4.96%	4.54%	4.72%
Distribution | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Average composite depreciation rates on utility property, plant and equipment (percentage)	2.42%	2.55%	2.45%
Merchant Generation Nuclear
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	44 years
Minimum | Merchant Generation-Other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	15 years
Minimum | Nonutility Gas Gathering and Processing
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Minimum | Nonutility Gas Gathering and Processing | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	10 years
Minimum | General and Other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Maximum | Merchant Generation-Other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	40 years
Maximum | Nonutility Gas Gathering and Processing
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	50 years
Maximum | Nonutility Gas Gathering and Processing | Dominion Energy Gas Holdings, LLC
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	50 years
Maximum | General and Other
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives	59 years

Significant Accounting Polici63

Significant Accounting Policies (Other Operations and Maintenance Expenses and Other Income) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Component Of Other Income And Expense [Line Items]
Other operations and maintenance expense		$ 3,068	$ 3,243	$ 2,711
Other income	[1]	358	429	312
Dominion Energy Gas Holdings, LLC
Component Of Other Income And Expense [Line Items]
Other income		104	87	63
Scenario, Previously Reported
Component Of Other Income And Expense [Line Items]
Other operations and maintenance expense		2,875	3,064	2,595
Other income		165	250	16
Scenario, Previously Reported | Dominion Energy Gas Holdings, LLC
Component Of Other Income And Expense [Line Items]
Other operations and maintenance expense		440	393	326
Other income		$ 20	$ 11	$ 1
[1]	See Note 9 for amounts attributable to related parties.

Acquisitions and Dispositions64

Acquisitions and Dispositions (Proposed Acquisition Of Scana) (Narrative) (Detail) - Subsequent Event $ in Millions	1 Months Ended
	Jan. 31, 2018USD ($)shares
Business Acquisition [Line Items]
Contract termination fee	$ 280
SCANA [Member]
Business Acquisition [Line Items]
Common stock agreed to issue | shares	0.6690
Business combination, liability incurred	$ 575
Combination debt outstanding	7,000
Contract termination fee	$ 240
SCANA [Member] | Minimum
Business Acquisition [Line Items]
Discount on existing customers	5.00%
SCANA [Member] | Up-front Payment Arrangement [Member]
Business Acquisition [Line Items]
Business combination, liability incurred	$ 1,300
V.C. Summer Units [Member]
Business Acquisition [Line Items]
Business combination cost related to exclusion from rate recovery	1,700
Columbia energy.
Business Acquisition [Line Items]
Business combination cost related to exclusion from rate recovery	$ 180

Acquisitions and Dispositions65

Acquisitions and Dispositions (Acquisition of Dominion Energy Questar) (Narrative) (Detail) - USD ($) $ / shares in Units, $ in Millions

Dec. 01, 2016

Sep. 16, 2016

Jul. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

Aug. 31, 2016

Apr. 30, 2016

Sep. 30, 2017

Dec. 31, 2016

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Business Acquisition [Line Items]

Issuance of common stock

$ 1,302

$ 2,152

$ 786

Issuance of short-term notes

1,200

600

Issuance of common stock

1,302

2,152

786

Other Commitment, Fiscal Year Maturity [Abstract]

Repayment of short-term notes

$ 250

$ 1,800

$ 400

Dominion Energy Questar Pipeline LLC | Dominion Energy Midstream Partners, LP | Subsidiary of Common Parent | Disposal Group, Disposed of by Sale, Not Discontinued Operations

Other Commitment, Fiscal Year Maturity [Abstract]

Cash consideration

$ 823

Debt financed distribution

300

Amount of consideration

1,300

Dominion Energy Questar Pipeline LLC | Dominion Energy Midstream Partners, LP | Subsidiary of Common Parent | Partnership Interest | Disposal Group, Disposed of by Sale, Not Discontinued Operations

Other Commitment, Fiscal Year Maturity [Abstract]

Combined value of common and convertible preferred units

$ 467

Dominion Energy Questar Pipeline LLC | Dominion Energy Midstream Partners, LP | Limited Partner | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Senior Unsecured Promissory Note Payable | Notes Payable, Other Payables

Other Commitment, Fiscal Year Maturity [Abstract]

Repayments of promissory note

$ 301

Dominion Energy Questar Pipeline LLC | Dominion Energy Midstream Partners, LP | Limited Partner | Common Units | Disposal Group, Disposed of by Sale, Not Discontinued Operations

Other Commitment, Fiscal Year Maturity [Abstract]

Number of common units to be purchased

6,656,839

Questar Fueling Company | Disposal Group, Disposed of by Sale, Not Discontinued Operations

Other Commitment, Fiscal Year Maturity [Abstract]

Cash consideration

$ 28

Underwritten Public Offering

Business Acquisition [Line Items]

Issuance of common stock

$ 756

Term Loans | Dominion Energy Questar Pipeline LLC | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Private Placement Term Loan Agreement Maturing in September 2017

Other Commitment, Fiscal Year Maturity [Abstract]

Repayment of short-term notes

$ 1,200

Capital Unit, Class A

Business Acquisition [Line Items]

Issuance of common stock

$ 1,000

Dominion Energy Questar Corporation

Business Acquisition [Line Items]

Price per share

$ 25

Total consideration

$ 4,400

Number of shares of Dominion Questar outstanding at closing

175,500,000

Issuance of senior notes

$ 1,300

Increase (decrease) to goodwill related modifications to preliminary valuation amounts

$ 6

$ (6)

Contributions to fund Dominion Questar's qualified and non-qualified defined benefit pension plans

$ 75

Dominion Energy Questar Corporation | Commitment for Charitable Contributions

Other Commitment, Fiscal Year Maturity [Abstract]

Charitable contributions, next twelve months

1

Charitable contributions, second year

1

Charitable contributions, third year

1

Charitable contributions, fourth year

1

Charitable contributions, fifth year

$ 1

Dominion Energy Questar Corporation | Commitment for Charitable Contributions | Minimum

Other Commitment, Fiscal Year Maturity [Abstract]

Period for charitable contributions

5 years

Dominion Energy Questar Corporation | White River Hub LLC

Business Acquisition [Line Items]

Ownership percentage

50.00%

Dominion Energy Questar Corporation | Underwritten Public Offering

Business Acquisition [Line Items]

Issuance of common stock

$ 500

Dominion Energy Questar Corporation | Term Loans

Business Acquisition [Line Items]

Issuance of short-term notes

$ 1,200

Dominion Energy Questar Corporation | Capital Unit, Class A

Business Acquisition [Line Items]

Issuance of common stock

$ 1,400

Acquisitions and Dispositions66

Acquisitions and Dispositions (Schedule of Preliminary Allocation of Purchase Price to Assets Acquired and Liabilities Assumed) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Sep. 16, 2016	Dec. 31, 2015
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Goodwill	[1]	$ 6,405	$ 6,399		$ 3,294
Dominion Energy Questar Corporation
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Total current assets				$ 224
Investments	[2]			58
Property, plant and equipment	[3]			4,131
Goodwill				3,111
Total deferred charges and other assets, excluding goodwill				75
Total Assets				7,599
Total current liabilities	[4]			793
Long-term debt	[5]			963
Deferred income taxes				807
Regulatory liabilities				259
Asset retirement obligations				160
Other deferred credits and other liabilities				220
Total Liabilities				3,202
Total estimated purchase price				$ 4,397
[1]	Goodwill amounts do not contain any accumulated impairment losses.
[2]	Includes $40 million for an equity method investment in White River Hub. The fair value adjustment on the equity method investment in White River Hub is considered to be equity method goodwill and is not amortized.
[3]	Nonregulated property, plant and equipment, excluding land, will be depreciated over remaining useful lives primarily ranging from 9 to 18 years.
[4]	Includes $301 million of short-term debt, of which no amounts remain outstanding at December 31, 2017, as well as a $250 million variable interest rate term loan due in August 2017 that was paid in July 2017.
[5]	Unsecured senior and medium-term notes with maturities which range from 2017 to 2048 and bear interest at rates from 2.98% to 7.20%.

Acquisitions and Dispositions67

Acquisitions and Dispositions (Schedule of Preliminary Allocation of Purchase Price to Assets Acquired and Liabilities Assumed) (Parenthetical) (Detail) - Dominion Energy Questar Corporation - USD ($) $ in Millions	Sep. 16, 2016	Dec. 31, 2017
Business Acquisition [Line Items]
Short-term debt	$ 301
White River Hub LLC
Business Acquisition [Line Items]
Equity method investment	$ 40
Minimum
Business Acquisition [Line Items]
Estimated Useful Lives	9 years
Maximum
Business Acquisition [Line Items]
Estimated Useful Lives	18 years
Unsecured Senior Notes | Minimum
Business Acquisition [Line Items]
Interest rate (percentage)		2.98%
Unsecured Senior Notes | Maximum
Business Acquisition [Line Items]
Interest rate (percentage)		7.20%
Variable Interest Rate Short Term Loan Due in August 2017 [Member]
Business Acquisition [Line Items]
Short-term note outstanding	$ 250

Acquisitions and Dispositions68

Acquisitions and Dispositions (Results of Operations and Pro Forma Information) (Narrative) (Detail) - Dominion Energy Questar Corporation - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Increase in operating revenue		$ 379
Increase in net income		73
Other operations and maintenance
Business Acquisition [Line Items]
Transaction and transition costs incurred	$ 26	58
Interest And Related Charges
Business Acquisition [Line Items]
Transaction and transition costs incurred		$ 16

Acquisitions and Dispositions69

Acquisitions and Dispositions (Schedule of Unaudited Pro Forma Information) (Detail) - Dominion Energy Questar Corporation - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	[1]	Dec. 31, 2015
Business Acquisition [Line Items]
Operating Revenue	$ 12,497		$ 12,818
Net income attributable to Dominion Energy	$ 2,300		$ 2,108
Earnings Per Common Share - Basic	$ 3.73		$ 3.56
Earnings Per Common Share - Diluted	$ 3.73		$ 3.55
[1]	Amounts include adjustments for non-recurring costs directly related to the Dominion Energy Questar Combination.

Acquisitions and Dispositions70

Acquisitions and Dispositions (Schedule of Acquisitions of Solar Projects) (Detail) $ in Millions

1 Months Ended

12 Months Ended

Oct. 31, 2017USD ($)ProjectMW

Sep. 30, 2017USD ($)ProjectMW

Jun. 30, 2017USD ($)ProjectMW

May 31, 2017USD ($)ProjectMW

Mar. 31, 2017USD ($)ProjectMW

Feb. 28, 2017USD ($)ProjectMW

Nov. 30, 2015USD ($)ProjectMW

Jul. 31, 2015USD ($)ProjectMW

Jun. 30, 2015USD ($)ProjectMW

Apr. 30, 2015USD ($)ProjectMW

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Business Acquisition [Line Items]

Project Cost

$ 405

$ 40

$ 418

EC&R NA Solar PV, LLC

Business Acquisition [Line Items]

Number of Projects | Project

1

1

Total consideration

[1]

$ 65

$ 66

Project Cost

[2]

$ 65

$ 66

MW Capacity | MW

20

20

EDF Renewable Development, Inc.

Business Acquisition [Line Items]

Number of Projects | Project

1

3

[3]

Total consideration

[1]

$ 68

$ 106

[3]

Project Cost

[2]

$ 68

$ 106

[3]

MW Capacity | MW

18

24

[3]

Sun Peak Solar LLC

Business Acquisition [Line Items]

Number of Projects | Project

1

Total consideration

[1]

$ 42

Project Cost

[2]

$ 71

MW Capacity | MW

20

Community Energy Solar, Inc

Business Acquisition [Line Items]

Number of Projects | Project

1

1

Total consideration

[1]

$ 29

$ 34

Project Cost

[2]

$ 205

$ 212

MW Capacity | MW

100

80

Solar Frontier Americas Holding, LLC

Business Acquisition [Line Items]

Number of Projects | Project

[4]

1

Total consideration

[1]

$ 77

Project Cost

[2]

$ 78

MW Capacity | MW

30

Solar Projects from Cypress Creek Renewables, LLC

Business Acquisition [Line Items]

Number of Projects | Project

1

Total consideration

[1]

$ 154

Project Cost

[2]

$ 160

MW Capacity | MW

79

Hecate Energy Virginia C&C LLC

Business Acquisition [Line Items]

Number of Projects | Project

1

1

Total consideration

[1]

$ 40

$ 16

Project Cost

[2]

$ 41

$ 16

MW Capacity | MW

20

10

Strata Solar Development, LLC/Moorings Farm 2 Holdco, LLC

Business Acquisition [Line Items]

Number of Projects | Project

2

Total consideration

[1]

$ 20

Project Cost

[2]

$ 20

MW Capacity | MW

10

Strata Solar Development, LLC

Business Acquisition [Line Items]

Number of Projects | Project

2

Total consideration

[1]

$ 20

Project Cost

[2]

$ 21

MW Capacity | MW

10

[1]

The purchase price was primarily allocated to Property, Plant and Equipment.

[2]

Includes acquisition cost.

[3]

One of the projects, Marin Carport, began commercial operations in 2016.

[4]

In April 2017, Dominion Energy discontinued efforts on the acquisition of the additional 20 MW solar project from Solar Frontier Americas Holding LLC.

Acquisitions and Dispositions71

Acquisitions and Dispositions (Schedule of Acquisitions of Solar Projects) (Parenthetical) (Detail)	1 Months Ended
	Apr. 30, 2017MW
Business Combinations Discontinued Operations And Disposal Groups [Abstract]
Discontinued efforts on acquisition of additional MW capacity	20

Acquisitions and Dispositions72

Acquisitions and Dispositions (Merchant Solar Projects) (Narrative) (Detail) $ in Millions	1 Months Ended		12 Months Ended
	Dec. 31, 2015USD ($)Project	Sep. 30, 2015ProjectMW	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)ProjectMW	Dec. 31, 2015USD ($)	Jan. 31, 2016USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Project Cost			$ 405	$ 40	$ 418
Merchant Solar Projects | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
MW Capacity | MW		425
Number of solar projects | Project		24
Total number of solar projects related to potential sale | Project	15
Amount of consideration	$ 184				$ 184	$ 117
Merchant Solar Projects | Disposal Group, Disposed of by Sale, Not Discontinued Operations | SunEdison, Inc
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of equity interest sold to non-controlling interest owners		33.00%
Terra Nova Renewable Partners | Call Option | Merchant Solar Projects
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage ownership in total units			67.00%
Number of Solar Development Projects in Operation [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of equity interests acquired				100.00%
Number of Projects | Project				7
Aggregate purchase price				$ 32
Project Cost				$ 421
MW Capacity | MW				221

Acquisitions and Dispositions73

Acquisitions and Dispositions (Narrative) (Detail) $ / shares in Units, $ in Millions

Apr. 01, 2015USD ($)$ / sharesshares

Dec. 31, 2015USD ($)MW

Sep. 30, 2015USD ($)miMWshares

Jun. 30, 2015USD ($)ProjectMW

Jan. 31, 2015USD ($)mi

Sep. 30, 2016USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2017USD ($)

Nov. 30, 2016

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Project Cost

$ 405

$ 40

$ 418

Goodwill

[1]

$ 3,294

6,405

6,399

3,294

$ 6,405

DECG

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Percentage of equity interests acquired

100.00%

Purchase price

$ 497

Net property plant and equipment acquired

$ 277

Length of FERC regulated interstate natural gas pipeline (in miles) (nearly 1,500 miles) | mi

1,500

Goodwill

$ 250

Amount expected to be deductible for tax purposes

225

Amount of regulatory liabilities

$ 38

Four Brothers Solar, LLC

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Percentage of equity interests acquired

50.00%

Number of Projects | Project

4

Purchase price

$ 64

Acquisition price in cash

2

Acquisition price payable

$ 62

MW Capacity | MW

320

Project Cost

$ 670

Purchase price

$ 64

Net property plant and equipment acquired

89

Amount of noncontrolling interest

$ 25

Three Cedars

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Percentage of equity interests acquired

50.00%

Number of Projects

3

Purchase price

$ 43

Acquisition price in cash

6

Acquisition price payable

$ 37

MW Capacity | MW

210

Project Cost

$ 450

Purchase price

$ 43

Net property plant and equipment acquired

65

Amount of noncontrolling interest

$ 22

Three Cedars | Current Liabilities

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Payable included in other current liabilities

$ 0

2

$ 0

Four Brothers and Three Cedars | Investment Credits | IRS

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Percentage of federal investment tax credits on projects claimed

99.00%

99.00%

Iroquois

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Ownership percentage

50.00%

50.00%

Partnership Interest | Iroquois | National Grid

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Ownership interest percentage

20.40%

Partnership Interest | Iroquois | NJNR Pipeline Company

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Ownership interest percentage

5.53%

Dominion Energy Midstream Partners, LP | Iroquois

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Ownership percentage

25.93%

25.93%

25.93%

Dominion Energy Midstream Partners, LP | Partnership Interest | Iroquois

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Length of FERC regulated interstate natural gas pipeline (in miles) (nearly 1,500 miles) | mi

416

Common units included in initial public offering | shares

8,600,000

Value of common units at closing

$ 216

Dominion Energy Midstream Partners, LP | Partnership Interest | Iroquois | National Grid

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Common units included in initial public offering | shares

6,800,000

Dominion Energy Midstream Partners, LP | Partnership Interest | Iroquois | NJNR Pipeline Company

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Common units included in initial public offering | shares

1,800,000

Dominion Energy Midstream Partners, LP | Disposal Group, Disposed of by Sale, Not Discontinued Operations | DECG | Affiliated Entity

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Ownership interest percentage

100.00%

Sales price

$ 501

Dominion Energy Midstream Partners, LP | Disposal Group, Disposed of by Sale, Not Discontinued Operations | DECG | Affiliated Entity | Unsecured Promissory Note Receivable | Notes Receivable

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Term of senior unsecured promissory note payable

2 years

Senior unsecured promissory note payable by Dominion Midstream

$ 301

Interest rate (percentage)

0.60%

Dominion Energy Midstream Partners, LP | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Partnership Interest | DECG | Affiliated Entity

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Common units included in initial public offering | shares

5,112,139

Value of common units at closing

$ 200

Number of trading days

10 days

Price per unit | $ / shares

$ 39.12

Dominion Energy Gas Holdings, LLC

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Goodwill

[1]

$ 542

$ 542

542

542

$ 542

Dominion Energy Gas Holdings, LLC | Iroquois

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Ownership percentage

24.07%

24.07%

Virginia Electric and Power Company

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Project Cost

$ 41

7

$ 43

Virginia Electric and Power Company | Morgans Corner Solar Energy, LLC

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Percentage of equity interests acquired

100.00%

100.00%

Purchase price

$ 47

MW Capacity | MW

20

Virginia Electric and Power Company | Morgans Corner Solar Energy, LLC | Supply Agreement with US Navy

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Duration of supply agreement

10 years

Virginia Electric and Power Company | Morgans Corner Solar Energy, LLC | Solar Development Project

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Total cost of project placed into service

$ 49

$ 49

NRG Energy, Inc

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Contributions from SunEdison and NRG to Four Brothers and Three Cedars

$ 9

NRG Energy, Inc | Four Brothers and Three Cedars

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Percentage of equity interests acquired

50.00%

Sun Edison Inc

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Contributions from SunEdison and NRG to Four Brothers and Three Cedars

$ 189

$ 103

Sun Edison Inc | Four Brothers and Three Cedars

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Contributions from SunEdison and NRG to Four Brothers and Three Cedars

$ 301

[1]

Goodwill amounts do not contain any accumulated impairment losses.

Operating Revenue (Schedule of

Operating Revenue (Schedule of Operating Revenue) (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Electric sales:
Regulated									$ 7,383		$ 7,348		$ 7,482
Nonregulated									1,429		1,519		1,488
Gas sales:
Regulated									1,067		500		218
Nonregulated									457		354		471
Gas transportation and storage									1,786		1,636		1,616
Other									464		380		408
Total operating revenue	$ 3,210	$ 3,179	$ 2,813	$ 3,384	$ 3,086	$ 3,132	$ 2,598	$ 2,921	12,586	[1]	11,737	[1]	11,683	[1]
Virginia Electric and Power Company
Electric sales:
Regulated									7,383		7,348		7,482
Gas sales:
Other									173		240		140
Total operating revenue	1,824	2,154	1,747	1,831	1,711	2,211	1,776	1,890	7,556		7,588		7,622
Dominion Energy Gas Holdings, LLC
Gas sales:
Regulated									87		119		122
Nonregulated									20		13		10
Gas transportation and storage									1,435		1,307		1,366
NGL revenue									91		62		93
Other									181		137		125
Total operating revenue	$ 501	$ 401	$ 422	$ 490	$ 457	$ 382	$ 368	$ 431	$ 1,814	[2]	$ 1,638	[2]	$ 1,716	[2]
[1]	See Note 9 for amounts attributable to related parties.
[2]	See Note 24 for amounts attributable to related parties.

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Federal statutory income tax rate				35.00%	35.00%	35.00%
Percentage of bonus depreciation allowance for qualifying expenditures incurred		50.00%		50.00%	50.00%	50.00%
Percentage of investment tax credit for qualifying expenditures to be incurred in 2019		30.00%		30.00%
Percentage of investment tax credit for qualifying expenditures to be incurred in 2020		26.00%		26.00%
Percentage of investment tax credit for qualifying expenditures to be incurred in 2021		22.00%		22.00%
Percentage of investment tax credit for qualifying expenditures to be incurred in 2022		10.00%		10.00%
Percentage of investment tax credit for qualifying expenditures to be incurred thereafter		10.00%		10.00%
Deferred income tax expense		$ (851)		$ (851)
Provision for current income taxes				(27)	$ (70)	$ 51
Benefit for deferred income taxes					96
Decrease in unrecognized tax benefits due to settlement				23	8	5
Unrecognized tax benefits that would impact effective tax rate		31		31	45	69
Decrease in accumulated deferred income tax liability		3,100		3,100
Increase in regulatory liabilities				4,200
Increase in deferred tax asset				1,100
Increase (Decrease) in tax expense as a result of changes in unrecognized tax benefits				$ (9)	$ (18)	$ (6)
Virginia Electric and Power Company
Income Taxes [Line Items]
Federal statutory income tax rate				35.00%	35.00%	35.00%
Deferred income tax expense		(93)		$ (93)
Provision for current income taxes				505	$ 258	$ 408
Decrease in unrecognized tax benefits due to settlement	$ 8			8
Unrecognized tax benefits that would impact effective tax rate	2	3		3	9	$ 8
Interest income	$ 11
Decrease in accumulated deferred income tax liability		1,900		1,900
Increase in regulatory liabilities				2,600
Increase in deferred tax asset				700
Increase (Decrease) in tax expense as a result of changes in unrecognized tax benefits				$ (6)	$ 1
Dominion Energy Gas Holdings, LLC
Income Taxes [Line Items]
Federal statutory income tax rate				35.00%	35.00%	35.00%
Deferred income tax expense		(197)		$ (197)
Provision for current income taxes				24	$ (23)	$ 120
Decrease in unrecognized tax benefits due to settlement				7	4
Unrecognized tax benefits that would impact effective tax rate					5	19
Decrease in accumulated deferred income tax liability		800		800
Increase in regulatory liabilities				1,000
Increase in deferred tax asset				200
Increase (Decrease) in tax expense as a result of changes in unrecognized tax benefits				(5)	(11)
Maximum
Income Taxes [Line Items]
Decrease in Unrecognized tax benefits due to settlement negotiations and expiration of statutes of limitations		13		13
Amount that earnings could potentially increase if changes were to occur				12
Maximum | Virginia Electric and Power Company
Income Taxes [Line Items]
Increase (Decrease) in tax expense as a result of changes in unrecognized tax benefits						1
Decrease in Unrecognized tax benefits due to settlement negotiations and expiration of statutes of limitations		2		2
Amount that earnings could potentially increase if changes were to occur				2
Maximum | Dominion Energy Gas Holdings, LLC
Income Taxes [Line Items]
Unrecognized tax benefits that would impact effective tax rate		1		1
Increase (Decrease) in tax expense as a result of changes in unrecognized tax benefits						1
Decrease in Unrecognized tax benefits due to settlement negotiations and expiration of statutes of limitations		$ 1		1
Amount that earnings could potentially increase if changes were to occur				$ 1
Scenario, Forecast
Income Taxes [Line Items]
Federal statutory income tax rate			21.00%
Federal
Income Taxes [Line Items]
Federal tax credits					129
Realizable domestic production activities deduction					17
Federal | Dominion Midstream Partners, LP | Questar Pipeline, LLC | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Taxes [Line Items]
Provision for current income taxes					$ 212
Federal | IRS
Income Taxes [Line Items]
Benefit related to carryback recognized						$ 20
Tax year under ongoing examination				2,017

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense for Continuing Operations Including Noncontrolling Interests) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal		$ (1)	$ (155)	$ (24)
State		(26)	85	75
Total current expense (benefit)		(27)	(70)	51
Deferred:
Federal 2017 Tax Reform Act impact	$ (851)	(851)
Taxes before operating loss carryforwards and investment tax credits		739	1,050	384
Tax utilization expense (benefit) of operating loss carryforwards		174	(161)	539
Investment tax credits		(200)	(248)	(134)
State		132	50	66
Total deferred expense (benefit)		(6)	691	855
Investment tax credit-gross deferral		5	35
Investment tax credit-amortization		(2)	(1)	(1)
Total income tax expense (benefit)		(30)	655	905
Virginia Electric and Power Company
Current:
Federal		432	168	316
State		73	90	92
Total current expense (benefit)		505	258	408
Deferred:
Federal 2017 Tax Reform Act impact	(93)	(93)
Taxes before operating loss carryforwards and investment tax credits		319	435	154
Tax utilization expense (benefit) of operating loss carryforwards		4	(2)	96
Investment tax credits		(23)	(25)	(11)
State		59	27	13
Total deferred expense (benefit)		266	435	252
Investment tax credit-gross deferral		5	35
Investment tax credit-amortization		(2)	(1)	(1)
Total income tax expense (benefit)		774	727	659
Dominion Energy Gas Holdings, LLC
Current:
Federal		16	(27)	90
State		8	4	30
Total current expense (benefit)		24	(23)	120
Deferred:
Federal 2017 Tax Reform Act impact	$ (197)	(197)
Taxes before operating loss carryforwards and investment tax credits		199	239	156
Tax utilization expense (benefit) of operating loss carryforwards		5	(2)	6
State		20	1	1
Total deferred expense (benefit)		27	238	163
Total income tax expense (benefit)		$ 51	$ 215	$ 283

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Income Taxes at the U.S. Statutory Federal Income Tax Rate) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
U.S. statutory rate	35.00%	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	2.00%	2.40%	3.70%
Investment tax credits	(6.30%)	(11.70%)	(4.70%)
Production tax credits	(0.70%)	(0.80%)	(0.80%)
Valuation allowances	0.20%	1.20%	(0.30%)
Federal legislative change	(27.50%)
State legislative change		(0.60%)	(0.10%)
AFUDC-equity	(1.40%)	(0.60%)	(0.30%)
Employee stock ownership plan deduction	(0.60%)	(0.60%)	(0.60%)
Other, net	(1.70%)	(1.40%)	0.10%
Effective tax rate	(1.00%)	22.90%	32.00%
Virginia Electric and Power Company
Income Tax Contingency [Line Items]
U.S. statutory rate	35.00%	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	3.70%	3.80%	3.90%
Investment tax credits	(0.80%)		(0.60%)
Production tax credits	(0.40%)	(0.50%)	(0.60%)
Valuation allowances		0.10%
Federal legislative change	(4.00%)
AFUDC-equity	(0.60%)	(0.60%)	(0.60%)
Other, net	0.60%	(0.40%)	0.60%
Effective tax rate	33.50%	37.40%	37.70%
Dominion Energy Gas Holdings, LLC
Income Tax Contingency [Line Items]
U.S. statutory rate	35.00%	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	2.40%	0.50%	2.70%
Valuation allowances	0.30%
Federal legislative change	(29.50%)
AFUDC-equity	(0.90%)	(0.20%)	0.20%
Other, net	0.40%	0.10%	0.30%
Effective tax rate	7.70%	35.40%	38.20%

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Income Taxes) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Deferred income taxes:
Total deferred income tax assets	$ 2,686	$ 1,827
Total deferred income tax liabilities	7,158	10,381
Total net deferred income tax liabilities	4,472	8,554
Plant and equipment, primarily depreciation method and basis differences	5,056	7,782
Excess deferred income taxes	(1,050)
Nuclear decommissioning	829	1,240
Deferred state income taxes	834	747
Federal benefit of deferred state income taxes	(175)	(261)
Deferred fuel, purchased energy and gas costs	1	(25)
Pension benefits	141	155
Other postretirement benefits	(51)	(68)
Loss and credit carryforwards	(1,536)	(1,547)
Valuation allowances	146	135
Partnership basis differences	473	688
Other	(196)	(292)
Total net deferred income tax liabilities	4,472	8,554
Deferred Investment Tax Credits - Regulated Operations	51	48
Total Deferred Taxes and Deferred Investment Tax Credits	4,523	8,602
Virginia Electric and Power Company
Deferred income taxes:
Total deferred income tax assets	923	268
Total deferred income tax liabilities	3,600	5,323
Total net deferred income tax liabilities	2,677	5,055
Plant and equipment, primarily depreciation method and basis differences	2,969	4,604
Excess deferred income taxes	(687)
Nuclear decommissioning	260	406
Deferred state income taxes	378	321
Federal benefit of deferred state income taxes	(79)	(112)
Deferred fuel, purchased energy and gas costs	(3)	(29)
Pension benefits	(104)	(138)
Other postretirement benefits	44	49
Loss and credit carryforwards	(111)	(88)
Valuation allowances	5	3
Other	5	39
Total net deferred income tax liabilities	2,677	5,055
Deferred Investment Tax Credits - Regulated Operations	51	48
Total Deferred Taxes and Deferred Investment Tax Credits	2,728	5,103
Dominion Energy Gas Holdings, LLC
Deferred income taxes:
Total deferred income tax assets	320	126
Total deferred income tax liabilities	1,774	2,564
Total net deferred income tax liabilities	1,454	2,438
Plant and equipment, primarily depreciation method and basis differences	1,132	1,726
Excess deferred income taxes	(244)
Deferred state income taxes	227	204
Federal benefit of deferred state income taxes	(48)	(71)
Deferred fuel, purchased energy and gas costs	2	4
Pension benefits	419	646
Other postretirement benefits	(2)	(6)
Loss and credit carryforwards	(4)	(5)
Valuation allowances	3
Partnership basis differences	26	43
Other	(57)	(103)
Total net deferred income tax liabilities	1,454	2,438
Total Deferred Taxes and Deferred Investment Tax Credits	$ 1,454	$ 2,438

Income Taxes (Schedule of Deduc

Income Taxes (Schedule of Deductible Loss and Credit Carryforwards) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Deductible loss and credit carryforwards [Line Items]
Deferred Tax Asset	$ 1,536	$ 1,547
Valuation Allowance	(146)
Deductible amount	1,926
Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Deferred Tax Asset	111	88
Valuation Allowance	(5)
Deductible amount	1
Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Deferred Tax Asset	4	$ 5
Valuation Allowance	(3)
Deductible amount	33
Federal
Deductible loss and credit carryforwards [Line Items]
Losses, Deferred tax asset	118
Deductible amount	560
Losses, Valuation allowance	0
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	58
Tax Credits, Valuation allowance	0
Federal | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Deductible amount	1
Losses, Valuation allowance	0
Federal | Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	1
Tax Credits, Valuation allowance	0
Federal | Investment Credits
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	938
Tax Credits, Valuation allowance	0
Federal | Investment Credits | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	51
Tax Credits, Valuation allowance	0
Federal | Federal production credits
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	129
Tax Credits, Valuation allowance	0
Federal | Federal Production And Other Credits [Member] | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	51
Tax Credits, Valuation allowance	0
State
Deductible loss and credit carryforwards [Line Items]
Losses, Deferred tax asset	103
Deductible amount	1,366
Losses, Valuation allowance	(63)
Tax credits, Deductible amount	0
State minimum tax credits	90
Tax Credits, Valuation allowance	0
State | Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Losses, Deferred tax asset	3
Deductible amount	33
Losses, Valuation allowance	(3)
State | Investment Credits | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	9
Tax Credits, Valuation allowance	(5)
State | Investment and Other Credit
Deductible loss and credit carryforwards [Line Items]
Tax credits, Deductible amount	0
Tax credits, Deferred tax asset	100
Tax Credits, Valuation allowance	$ (83)
Earliest Tax Year [Member] | Federal
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,031
Earliest Tax Year [Member] | Federal | Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,032
Earliest Tax Year [Member] | Federal | Investment Credits
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,033
Earliest Tax Year [Member] | Federal | Investment Credits | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,034
Earliest Tax Year [Member] | Federal | Federal production credits
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,031
Earliest Tax Year [Member] | Federal | Federal Production And Other Credits [Member] | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,031
Earliest Tax Year [Member] | State
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2,018
Earliest Tax Year [Member] | State | Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2,036
Earliest Tax Year [Member] | State | Investment and Other Credit
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,018
Latest Tax Year [Member] | Federal
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2,034
Tax Credits, Expiration Period	2,037
Latest Tax Year [Member] | Federal | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2,034
Latest Tax Year [Member] | Federal | Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,036
Latest Tax Year [Member] | Federal | Investment Credits
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,037
Latest Tax Year [Member] | Federal | Investment Credits | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,037
Latest Tax Year [Member] | Federal | Federal production credits
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,037
Latest Tax Year [Member] | Federal | Federal Production And Other Credits [Member] | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,037
Latest Tax Year [Member] | State
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2,037
Latest Tax Year [Member] | State | Dominion Energy Gas Holdings, LLC
Deductible loss and credit carryforwards [Line Items]
Losses, Expiration Period	2,037
Latest Tax Year [Member] | State | Investment Credits | Virginia Electric and Power Company
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,024
Latest Tax Year [Member] | State | Investment and Other Credit
Deductible loss and credit carryforwards [Line Items]
Tax Credits, Expiration Period	2,027

Income Taxes (Unrecognized Tax

Income Taxes (Unrecognized Tax Benefits) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1		$ 64	$ 103	$ 145
Increases-prior period positions		1	9	2
Decreases-prior period positions		(9)	(44)	(40)
Increases-current period positions		5	6	8
Settlements with tax authorities		(23)	(8)	(5)
Expiration of statutes of limitations			(2)	(7)
Balance at December 31		38	64	103
Virginia Electric and Power Company
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1		13	12	36
Increases-prior period positions			4
Decreases-prior period positions		(1)	(3)	(25)
Increases-current period positions				1
Settlements with tax authorities	$ (8)	(8)
Balance at December 31		4	13	12
Dominion Energy Gas Holdings, LLC
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1		7	29	29
Increases-prior period positions			1
Decreases-prior period positions			(19)
Settlements with tax authorities		$ (7)	(4)
Balance at December 31			$ 7	$ 29

Income Taxes (Earliest Tax Year

Income Taxes (Earliest Tax Year) (Detail)	12 Months Ended
	Dec. 31, 2017
Pennsylvania
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2,012	[1]
Connecticut
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2,014
Virginia
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2,014	[2]
West Virginia
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2,014	[1]
New York
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2,011	[1]
Utah
Operation In Major Geographical Areas Tax Year [Line Items]
Earliest Open Tax Year	2,014
[1]	Considered a major state for Dominion Energy Gas' operations.
[2]	Considered a major state for Virginia Power's operations.

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value, Option, Quantitative Disclosures) (Detail) $ in Millions		12 Months Ended
		Dec. 31, 2017USD ($)$ / MWh$ / DTH$ / gal	Dec. 31, 2016USD ($)
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		$ 307	$ 279
Fair Value of Derivative Liabilities		284	155
Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		166	194
Fair Value of Derivative Liabilities		66	31
Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		32
Fair Value of Derivative Liabilities		8	11
Fair Value, Measurements, Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Total Assets		5,379	4,722
Total Liabilities		284	155
Fair Value, Measurements, Recurring | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Total Assets		2,466	2,200
Total Liabilities		66	31
Fair Value, Measurements, Recurring | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Total Assets		32
Total Liabilities		8	11
Fair Value, Measurements, Recurring | Commodity
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		258	262
Fair Value of Derivative Liabilities		197	96
Fair Value, Measurements, Recurring | Commodity | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		166	188
Fair Value of Derivative Liabilities		9	10
Fair Value, Measurements, Recurring | Commodity | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Liabilities		6	5
Fair Value, Measurements, Recurring | Level 3
Fair Value, Option, Quantitative Disclosures [Line Items]
Total Assets		157	147
Total Liabilities		7	8
Fair Value, Measurements, Recurring | Level 3 | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Total Assets		152	145
Total Liabilities		5	2
Fair Value, Measurements, Recurring | Level 3 | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Total Liabilities		2	2
Fair Value, Measurements, Recurring | Level 3 | Commodity
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		157	147
Fair Value of Derivative Liabilities		7	8
Fair Value, Measurements, Recurring | Level 3 | Commodity | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		152	145
Fair Value of Derivative Liabilities		5	2
Fair Value, Measurements, Recurring | Level 3 | Commodity | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Liabilities		2	$ 2
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | FTRs [Member] | Commodity
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		29
Fair Value of Derivative Liabilities		5
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | FTRs [Member] | Commodity | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		27
Fair Value of Derivative Liabilities		$ 5
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | FTRs [Member] | Commodity | Liabilities | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	(4)
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | FTRs [Member] | Commodity | Liabilities | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	(4)
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | FTRs [Member] | Commodity | Liabilities | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	6
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | FTRs [Member] | Commodity | Liabilities | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	6
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Liabilities		$ 2
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Liabilities | Minimum | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	0
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Liabilities | Maximum | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	1
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Liabilities | Weighted Average | Dominion Energy Gas Holdings, LLC
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1],[2]	1
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Commodity
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Liabilities	[3]	$ 2
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Commodity | Liabilities | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / gal	[1]	0
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Commodity | Liabilities | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / gal	[1]	2
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas Liquids [Member] | Commodity | Liabilities | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / gal	[1],[2]	1
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Assets | FTRs [Member] | Commodity | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	(1)
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Assets | FTRs [Member] | Commodity | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	(1)
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Assets | FTRs [Member] | Commodity | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	7
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Assets | FTRs [Member] | Commodity | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	7
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Assets | FTRs [Member] | Commodity | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1],[2]	2
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Assets | FTRs [Member] | Commodity | Weighted Average | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1],[2]	2
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Commodity
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets	[4]	$ 84
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Commodity | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets	[4]	$ 81
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Assets | Commodity | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	(2)
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Assets | Commodity | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	(2)
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Assets | Commodity | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	14
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Assets | Commodity | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	7
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Assets | Commodity | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1],[2]	0
Fair Value, Measurements, Recurring | Discounted Cash Flow [Member] | Level 3 | Natural Gas | Assets | Commodity | Weighted Average | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1],[2]	(1)
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Electricity | Physical Options [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		$ 43
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Electricity | Physical Options [Member] | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		$ 43
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Market Price [Member] | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	22
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Market Price [Member] | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	22
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Market Price [Member] | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	74
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Market Price [Member] | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1]	74
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Market Price [Member] | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1],[2]	37
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Market Price [Member] | Weighted Average | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / MWh	[1],[2]	37
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Price Volatility [Member] | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	13.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Price Volatility [Member] | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	13.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Price Volatility [Member] | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	63.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Price Volatility [Member] | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	63.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Price Volatility [Member] | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[2],[5]	33.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Assets | Electricity | Physical Options [Member] | Price Volatility [Member] | Weighted Average | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[2],[5]	33.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Physical Options [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		$ 1
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Physical Options [Member] | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Derivative Assets		$ 1
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Market Price [Member] | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	2
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Market Price [Member] | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	2
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Market Price [Member] | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	7
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Market Price [Member] | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1]	7
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Market Price [Member] | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1],[2]	3
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Market Price [Member] | Weighted Average | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Market Price | $ / DTH	[1],[2]	3
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Price Volatility [Member] | Minimum
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	26.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Price Volatility [Member] | Minimum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	26.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Price Volatility [Member] | Maximum
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	54.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Price Volatility [Member] | Maximum | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[5]	54.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Price Volatility [Member] | Weighted Average
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[2],[5]	33.00%
Fair Value, Measurements, Recurring | Option Model [Member] | Level 3 | Natural Gas | Assets | Physical Options [Member] | Price Volatility [Member] | Weighted Average | Virginia Electric and Power Company
Fair Value, Option, Quantitative Disclosures [Line Items]
Price volatility (percentage)	[2],[5]	33.00%
[1]	Represents market prices beyond defined terms for Levels 1 and 2.
[2]	Averages weighted by volume.
[3]	Includes NGLs and oil.
[4]	Includes basis.
[5]	Represents volatilities unrepresented in published markets.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Facility Limit		$ 5,500,000,000	$ 5,500,000,000
Revolving Credit Facility | Atlantic Coast Pipeline | Financial Guarantee [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Facility Limit		3,400,000,000			$ 3,400,000,000
Guarantee liability		30,000,000
Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Facility Limit	[1]	5,500,000,000	5,500,000,000
Unrealized gains and losses included in earnings in Level 3 fair value category		0	0	$ 0
Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Facility Limit	[2]	1,500,000,000	1,500,000,000
Unrealized gains and losses included in earnings in Level 3 fair value category		$ 0	$ 0	$ 0
[1]	The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion Energy, Dominion Energy Gas and Questar Gas. Sub-limits for Virginia Power are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Virginia Power was an aggregate $1.5 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These facilities mature in April 2020, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.
[2]	A maximum of a combined $1.5 billion of the facilities is available to Dominion Energy Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. Sub-limits for Dominion Energy Gas are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Dominion Energy Gas was an aggregate $500 million. If Dominion Energy Gas has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These credit facilities mature in April 2020 and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.5 billion (or the sub-limit, whichever is less) of letters of credit.

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities that are Measured at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		$ 307		$ 279
Derivative Liabilities		284		155
Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		166		194
Derivative Liabilities		66		31
Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		32
Derivative Liabilities		8		11
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		5,379		4,722
Total Liabilities		284		155
Fair Value, Measurements, Recurring | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		2,466		2,200
Total Liabilities		66		31
Fair Value, Measurements, Recurring | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		32
Total Liabilities		8		11
Fair Value, Measurements, Recurring | Equity securities: | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	3,493		2,913
Fair Value, Measurements, Recurring | Equity securities: | U.S. | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[2]	1,566		1,302
Fair Value, Measurements, Recurring | Fixed Income [Member] | Corporate debt instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	444		487
Fair Value, Measurements, Recurring | Fixed Income [Member] | Corporate debt instruments | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[2]	224		277
Fair Value, Measurements, Recurring | Fixed Income [Member] | Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	1,101		1,038
Fair Value, Measurements, Recurring | Fixed Income [Member] | Government Securities [Member] | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		494	[2]	427
Fair Value, Measurements, Recurring | Cash equivalents and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	34		5
Fair Value, Measurements, Recurring | Cash equivalents and other | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[2]	16
Fair Value, Measurements, Recurring | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		258		262
Derivative Liabilities		197		96
Fair Value, Measurements, Recurring | Commodity | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		166		188
Derivative Liabilities		9		10
Fair Value, Measurements, Recurring | Commodity | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities		6		5
Fair Value, Measurements, Recurring | Interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		17		17
Derivative Liabilities		85		53
Fair Value, Measurements, Recurring | Interest rate | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset				6
Derivative Liabilities		57		21
Fair Value, Measurements, Recurring | Foreign currency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		32
Derivative Liabilities		2		6
Fair Value, Measurements, Recurring | Foreign currency | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		32
Derivative Liabilities		2		6
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		3,834		3,342
Fair Value, Measurements, Recurring | Level 1 | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		1,750		1,438
Fair Value, Measurements, Recurring | Level 1 | Equity securities: | U.S.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	3,493		2,913
Fair Value, Measurements, Recurring | Level 1 | Equity securities: | U.S. | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[2]	1,566		1,302
Fair Value, Measurements, Recurring | Level 1 | Fixed Income [Member] | Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	307		424
Fair Value, Measurements, Recurring | Level 1 | Fixed Income [Member] | Government Securities [Member] | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		168	[2]	136
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	34		5
Fair Value, Measurements, Recurring | Level 1 | Cash equivalents and other | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[2]	16
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		1,388		1,233
Total Liabilities		277		147
Fair Value, Measurements, Recurring | Level 2 | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		564		617
Total Liabilities		61		29
Fair Value, Measurements, Recurring | Level 2 | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		32
Total Liabilities		6		9
Fair Value, Measurements, Recurring | Level 2 | Fixed Income [Member] | Corporate debt instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	444		487
Fair Value, Measurements, Recurring | Level 2 | Fixed Income [Member] | Corporate debt instruments | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[2]	224		277
Fair Value, Measurements, Recurring | Level 2 | Fixed Income [Member] | Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	[1]	794		614
Fair Value, Measurements, Recurring | Level 2 | Fixed Income [Member] | Government Securities [Member] | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		326	[2]	291
Fair Value, Measurements, Recurring | Level 2 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		101		115
Derivative Liabilities		190		88
Fair Value, Measurements, Recurring | Level 2 | Commodity | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		14		43
Derivative Liabilities		4		8
Fair Value, Measurements, Recurring | Level 2 | Commodity | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities		4		3
Fair Value, Measurements, Recurring | Level 2 | Interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		17		17
Derivative Liabilities		85		53
Fair Value, Measurements, Recurring | Level 2 | Interest rate | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset				6
Derivative Liabilities		57		21
Fair Value, Measurements, Recurring | Level 2 | Foreign currency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		32
Derivative Liabilities		2		6
Fair Value, Measurements, Recurring | Level 2 | Foreign currency | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		32
Derivative Liabilities		2		6
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		157		147
Total Liabilities		7		8
Fair Value, Measurements, Recurring | Level 3 | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets		152		145
Total Liabilities		5		2
Fair Value, Measurements, Recurring | Level 3 | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Liabilities		2		2
Fair Value, Measurements, Recurring | Level 3 | Commodity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		157		147
Derivative Liabilities		7		8
Fair Value, Measurements, Recurring | Level 3 | Commodity | Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset		152		145
Derivative Liabilities		5		2
Fair Value, Measurements, Recurring | Level 3 | Commodity | Dominion Energy Gas Holdings, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities		$ 2		$ 2
[1]	Includes investments held in the nuclear decommissioning and rabbi trusts. Excludes $88 million and $89 million of assets at December 31, 2017 and 2016, respectively, measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy.
[2]	Includes investments held in the nuclear decommissioning trusts. Excludes $27 million and $26 million of assets at December 31, 2017 and 2016, respectively, measured at fair value using NAV (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy.

Fair Value Measurements (Asse85

Fair Value Measurements (Assets and Liabilities that are Measured at Fair Value on a Recurring Basis) (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value using NAV	$ 88	$ 89
Virginia Electric and Power Company
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value using NAV	$ 27	$ 26

Fair Value Measurements (Net Ch

Fair Value Measurements (Net Change in the Assets and Liabilities Measured at Fair Value on a Recurring Basis and Included in the Level 3 Fair Value Category) (Detail) - Commodity - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at January 1,	$ 139	$ 95	$ 107
Total realized and unrealized gains (losses):
Included in earnings	(38)	(35)	(5)
Included in other comprehensive loss	(2)		(9)
Included in regulatory assets/liabilities	42	(39)	(4)
Settlements	6	38	9
Purchases		87
Transfers out of Level 3	3	(7)	(3)
Balance at December 31,	150	139	95
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets still held at the reporting date	2	(1)	2
Virginia Electric and Power Company
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at January 1,	143	93	102
Total realized and unrealized gains (losses):
Included in earnings	(43)	(35)	(13)
Included in regulatory assets/liabilities	40	(37)	(5)
Settlements	7	35	13
Purchases		87
Transfers out of Level 3			(4)
Balance at December 31,	147	143	93
Dominion Energy Gas Holdings, LLC
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at January 1,	(2)	6	2
Total realized and unrealized gains (losses):
Included in earnings			1
Included in other comprehensive loss	(3)		(5)
Settlements			(1)
Transfers out of Level 3	3	(8)	9
Balance at December 31,	$ (2)	$ (2)	$ 6

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Gains and Losses Included in the Level 3 Fair Value Category) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments Gain Loss [Line Items]
Total gains (losses) included in earnings	$ (38)	$ (35)	$ (5)
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date	2	(1)	2
Operating Revenue
Derivative Instruments Gain Loss [Line Items]
Total gains (losses) included in earnings	3	0	6
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date	2	0	1
Electric fuel and other energy-related purchases
Derivative Instruments Gain Loss [Line Items]
Total gains (losses) included in earnings	(42)	(35)	(11)
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date	0	(1)	1
Purchased Gas
Derivative Instruments Gain Loss [Line Items]
Total gains (losses) included in earnings	1	0	0
The amount of total gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date	$ 0	$ 0	$ 0

Fair Value Measurements (Financ

Fair Value Measurements (Financial Instruments' Carrying Amounts and Fair Values) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including securities due within one year	[1]	$ 28,666	$ 26,587
Junior subordinated notes	[2]	3,981	2,980
Remarketable subordinated notes	[2]	1,379	2,373
Carrying Amount | Virginia Electric and Power Company
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including securities due within one year	[2]	11,346	10,530
Carrying Amount | Dominion Energy Gas Holdings, LLC
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including securities due within one year	[3]	3,570	3,528
Estimate of Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including securities due within one year	[1],[4]	31,233	28,273
Junior subordinated notes	[2],[4]	4,102	2,893
Remarketable subordinated notes	[2],[4]	1,446	2,418
Estimate of Fair Value | Virginia Electric and Power Company
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including securities due within one year	[2],[4]	12,842	11,584
Estimate of Fair Value | Dominion Energy Gas Holdings, LLC
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including securities due within one year	[3],[4]	$ 3,719	$ 3,603
[1]	Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium, and foreign currency remeasurement adjustments. At December 31, 2017, and 2016, includes the valuation of certain fair value hedges associated with Dominion Energy's fixed rate debt of $(22) million and $(1) million, respectively
[2]	Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium.
[3]	Carrying amount includes amounts which represent the unamortized debt issuance costs, discount or premium, and foreign currency remeasurement adjustments.
[4]	Fair value is estimated using market prices, where available, and interest rates currently available for issuance of debt with similar terms and remaining maturities. All fair value measurements are classified as Level 2. The carrying amount of debt issues with short-term maturities and variable rates refinanced at current market rates is a reasonable estimate of their fair value.

Fair Value Measurements (Fina89

Fair Value Measurements (Financial Instruments' Carrying Amounts and Fair Values) (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Valuation of certain fair value hedges associated with fixed rate debt	$ (22)	$ (1)

Derivatives and Hedge Account90

Derivatives and Hedge Accounting Activities (Schedule of Offsetting Assets) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	$ 303	$ 272
Net Amounts of Assets Presented in the Consolidated Balance Sheet	303	272
Total derivatives, not subject to a master netting or similar arrangement	4	7
Gross Amounts of Recognized Assets, Total	307	279
Derivative Asset	307	279
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	99	67
Net Amounts	204	205
Virginia Electric and Power Company
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	155	153
Net Amounts of Assets Presented in the Consolidated Balance Sheet	155	153
Total derivatives, not subject to a master netting or similar arrangement	11	41
Gross Amounts of Recognized Assets, Total	166	194
Derivative Asset	166	194
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	4	2
Net Amounts	151	151
Dominion Energy Gas Holdings, LLC
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	32	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	32	0
Derivative Asset	32
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	2	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received	0	0
Net Amounts	30	0
Commodity | Over-the-counter
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	174	211
Net Amounts of Assets Presented in the Consolidated Balance Sheet	174	211
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	9	14
Net Amounts	165	197
Commodity | Exchange
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	80	44
Net Amounts of Assets Presented in the Consolidated Balance Sheet	80	44
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	80	44
Commodity | Virginia Electric and Power Company | Over-the-counter
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	155	147
Net Amounts of Assets Presented in the Consolidated Balance Sheet	155	147
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	4	2
Net Amounts	151	145
Interest rate | Over-the-counter
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	17	17
Net Amounts of Assets Presented in the Consolidated Balance Sheet	17	17
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	8	9
Net Amounts	9	8
Interest rate | Virginia Electric and Power Company | Over-the-counter
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets		6
Net Amounts of Assets Presented in the Consolidated Balance Sheet		6
Net Amounts		6
Foreign currency | Over-the-counter
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	32
Net Amounts of Assets Presented in the Consolidated Balance Sheet	32
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	2
Net Amounts	30
Foreign currency | Dominion Energy Gas Holdings, LLC | Over-the-counter
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	32	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet	32	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	2	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral Received	0	0
Net Amounts	$ 30	$ 0

Derivatives and Hedge Account91

Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	$ 283	$ 153
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	283	153
Total derivatives, not subject to a master netting or similar arrangement	1	2
Gross Amounts of Recognized Liabilities, Total	284	155
Derivative Liabilities	284	155
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	99	67
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral	46	27
Net Amounts	138	59
Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	61	23
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	61	23
Total derivatives, not subject to a master netting or similar arrangement	5	8
Gross Amounts of Recognized Liabilities, Total	66	31
Derivative Liabilities	66	31
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	4	2
Net Amounts	57	21
Dominion Energy Gas Holdings, LLC
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	8	11
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	8	11
Derivative Liabilities	8	11
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	2	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral	0	0
Net Amounts	6	11
Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	76	23
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	76	23
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	9	14
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral	6
Net Amounts	61	9
Commodity | Exchange
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	120	71
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	120	71
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	80	44
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral	40	27
Commodity | Virginia Electric and Power Company | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	4	2
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	4	2
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	4	2
Commodity | Dominion Energy Gas Holdings, LLC | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	6	5
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	6	5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	0	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral	0	0
Net Amounts	6	5
Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	85	53
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	85	53
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	8	9
Net Amounts	77	44
Interest rate | Virginia Electric and Power Company | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	57	21
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	57	21
Net Amounts	57	21
Foreign currency | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	2	6
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	2	6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	2
Net Amounts		6
Foreign currency | Dominion Energy Gas Holdings, LLC | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	2	6
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	2	6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments	2	0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral	0	0
Net Amounts	$ 0	$ 6

Derivatives and Hedge Account92

Derivatives and Hedge Accounting Activities (Volume of Derivative Activity) (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)MWhgalBcf
Fixed Price - Natural Gas - Non-current Derivative Contract [Member]
Derivative [Line Items]
Volume of derivative activity	19	[1]
Fixed Price - Natural Gas - Non-current Derivative Contract [Member] | Virginia Electric and Power Company
Derivative [Line Items]
Volume of derivative activity	5	[1]
Basis - Natural Gas - Non-current Derivative Contract [Member]
Derivative [Line Items]
Volume of derivative activity	600
Basis - Natural Gas - Non-current Derivative Contract [Member] | Virginia Electric and Power Company
Derivative [Line Items]
Volume of derivative activity	540
Fixed Price - Electricity - Non-current Derivative Contract [Member]
Derivative [Line Items]
Volume of electricity | MWh	364,990
Fixed Price - Electricity - Non-current Derivative Contract [Member] | Virginia Electric and Power Company
Derivative [Line Items]
Volume of electricity | MWh	364,990	[1]
Liquids - Non-current Derivative Contract [Member]
Derivative [Line Items]
Volume of derivative activity | gal	10,087,200	[2]
Liquids - Non-current Derivative Contract [Member] | Dominion Energy Gas Holdings, LLC
Derivative [Line Items]
Volume of derivative activity | gal	8,491,200
Interest Rate - Non-current Derivative Contract
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros) | $	$ 4,192,517,177	[3]
Interest Rate - Non-current Derivative Contract | Virginia Electric and Power Company
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros) | $	300,000,000	[3]
Foreign Exchange - Non- Current Derivative Contract [Member]
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros) | $	280,000,000	[3],[4]
Foreign Exchange - Non- Current Derivative Contract [Member] | Dominion Energy Gas Holdings, LLC
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros) | $	$ 280,000,000	[5]
Fixed Price - Natural Gas - Current Derivative Contract
Derivative [Line Items]
Volume of derivative activity	77	[1]
Fixed Price - Natural Gas - Current Derivative Contract | Virginia Electric and Power Company
Derivative [Line Items]
Volume of derivative activity	33	[1]
Basis - Natural Gas - Current Derivative Contract
Derivative [Line Items]
Volume of derivative activity	163
Basis - Natural Gas - Current Derivative Contract | Dominion Energy Gas Holdings, LLC
Derivative [Line Items]
Volume of derivative activity	1
Basis - Natural Gas - Current Derivative Contract | Virginia Electric and Power Company
Derivative [Line Items]
Volume of derivative activity	79
Fixed Price - Electricity - Current Derivative Contract
Derivative [Line Items]
Volume of electricity | MWh	10,552,363
Fixed Price - Electricity - Current Derivative Contract | Virginia Electric and Power Company
Derivative [Line Items]
Volume of electricity | MWh	1,453,910	[1]
Financial Transmission Rights - Electricity- Current Derivative Contract
Derivative [Line Items]
Volume of electricity | MWh	46,494,865
Liquids - Current Derivative Contract
Derivative [Line Items]
Volume of derivative activity | gal	44,153,704	[2]
Liquids - Current Derivative Contract | Dominion Energy Gas Holdings, LLC
Derivative [Line Items]
Volume of derivative activity | gal	40,961,704
Liquids - Current Derivative Contract | Virginia Electric and Power Company
Derivative [Line Items]
Volume of electricity | MWh	42,582,981
Interest Rate - Current Derivative Contract
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros) | $	$ 1,950,000,000	[3]
Interest Rate - Current Derivative Contract | Virginia Electric and Power Company
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros) | $	$ 1,150,000,000	[3]
[1]	Includes options.
[2]	Includes NGLs and oil.
[3]	Maturity is determined based on final settlement period.
[4]	Euro equivalent volumes are € 250,000,000.
[5]	Maturity is determined based on final settlement period. Euro equivalent volumes are €250,000,000.

Derivatives and Hedge Account93

Derivatives and Hedge Accounting Activities (Volume of Derivative Activity) (Parenthetical) (Detail) - Foreign currency	Dec. 31, 2017EUR (€)
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros)	€ 250,000,000
Dominion Energy Gas Holdings, LLC
Derivative [Line Items]
Interest rate / Foreign currency (US Dollars, Euros)	€ 250,000,000

Derivatives and Hedge Account94

Derivatives and Hedge Accounting Activities (Selected Information Related to Gains (Losses) on Cash Flow Hedges Included in AOCI) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (302)
Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	(73)
Commodity | Electricity
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	(55)
Commodities, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (55)
Maximum Term	12 months
Commodity | Other Energy Contract
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (4)
Commodities, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (4)
Maximum Term	15 months
Commodity | Natural Gas
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (2)
Commodities, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (3)
Maximum Term	34 months
Interest rate
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (246)
Interest rate, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (10)
Maximum Term	384 months
Foreign currency
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ 5
Foreign currency, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (1)
Maximum Term	102 months
Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (23)
Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	(8)
Dominion Energy Gas Holdings, LLC | Interest rate
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	(25)
Interest rate, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (3)
Maximum Term	324 months
Dominion Energy Gas Holdings, LLC | Foreign currency
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ 6
Foreign currency, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (1)
Maximum Term	102 months
Dominion Energy Gas Holdings, LLC | NGLs
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (4)
Commodities, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (4)
Maximum Term	15 months
Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	$ (12)
Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	(1)
Virginia Electric and Power Company | Interest rate
Derivative Instruments Gain Loss [Line Items]
AOCI After-Tax	(12)
Interest rate, Amounts Expected to be Reclassified to Earnings During the Next 12 Months After-Tax	$ (1)
Maximum Term	384 months

Derivatives and Hedge Account95

Derivatives and Hedge Accounting Activities (Fair Value of Derivatives) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Derivative Asset		$ 307	$ 279
Derivative Liabilities		284	155
Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset		166	194
Derivative Liabilities		66	31
Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Asset		32
Derivative Liabilities		8	11
Current Assets
Derivatives Fair Value [Line Items]
Derivative Asset	[1]	169	140
Current Assets | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		163	130
Current Assets | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset		6	10
Current Assets | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset	[2]	75	66
Current Assets | Virginia Electric and Power Company | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		75	60
Current Assets | Virginia Electric and Power Company | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset			6
Noncurrent Assets
Derivatives Fair Value [Line Items]
Derivative Asset	[3]	138	139
Noncurrent Assets | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		95	132
Noncurrent Assets | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset		11	7
Noncurrent Assets | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Asset		32
Noncurrent Assets | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset		91	128
Noncurrent Assets | Virginia Electric and Power Company | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		91	128
Noncurrent Assets | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Asset	[4]	32
Noncurrent Assets | Dominion Energy Gas Holdings, LLC | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Asset		32
Current Liabilities
Derivatives Fair Value [Line Items]
Derivative Liabilities	[5]	250	128
Current Liabilities | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		195	92
Current Liabilities | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		53	33
Current Liabilities | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities		2	3
Current Liabilities | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Liabilities	[6]	53	18
Current Liabilities | Virginia Electric and Power Company | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		9	10
Current Liabilities | Virginia Electric and Power Company | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		44	8
Current Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Liabilities	[7]	8	7
Current Liabilities | Dominion Energy Gas Holdings, LLC | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		6	4
Current Liabilities | Dominion Energy Gas Holdings, LLC | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities		2	3
Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivative Liabilities	[8]	34	27
Noncurrent Liabilities [Member] | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		2	4
Noncurrent Liabilities [Member] | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		32	20
Noncurrent Liabilities [Member] | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities			3
Noncurrent Liabilities [Member] | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Liabilities	[9]	13	13
Noncurrent Liabilities [Member] | Virginia Electric and Power Company | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		13	13
Noncurrent Liabilities [Member] | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Liabilities	[10]		4
Noncurrent Liabilities [Member] | Dominion Energy Gas Holdings, LLC | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities			1
Noncurrent Liabilities [Member] | Dominion Energy Gas Holdings, LLC | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities			3
Fair Value - Derivatives under Hedge Accounting [Member]
Derivatives Fair Value [Line Items]
Derivative Asset		54	46
Derivative Liabilities		191	111
Fair Value - Derivatives under Hedge Accounting [Member] | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset			6
Derivative Liabilities		57	21
Fair Value - Derivatives under Hedge Accounting [Member] | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Asset		32
Derivative Liabilities		8	11
Fair Value - Derivatives under Hedge Accounting [Member] | Current Assets
Derivatives Fair Value [Line Items]
Derivative Asset	[1]	11	39
Fair Value - Derivatives under Hedge Accounting [Member] | Current Assets | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		5	29
Fair Value - Derivatives under Hedge Accounting [Member] | Current Assets | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset		6	10
Fair Value - Derivatives under Hedge Accounting [Member] | Current Assets | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset	[2]		6
Fair Value - Derivatives under Hedge Accounting [Member] | Current Assets | Virginia Electric and Power Company | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset			6
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Assets
Derivatives Fair Value [Line Items]
Derivative Asset	[3]	43	7
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Assets | Interest rate
Derivatives Fair Value [Line Items]
Derivative Asset		11	7
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Assets | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Asset		32
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Assets | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Asset	[4]	32
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Assets | Dominion Energy Gas Holdings, LLC | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Asset		32
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities
Derivatives Fair Value [Line Items]
Derivative Liabilities	[5]	158	87
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		103	51
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		53	33
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities		2	3
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Liabilities	[6]	44	8
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Virginia Electric and Power Company | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		44	8
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Liabilities	[7]	8	7
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Dominion Energy Gas Holdings, LLC | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		6	4
Fair Value - Derivatives under Hedge Accounting [Member] | Current Liabilities | Dominion Energy Gas Holdings, LLC | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities		2	3
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivative Liabilities	[8]	33	24
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		1	1
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		32	20
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities			3
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Liabilities	[9]	13	13
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Virginia Electric and Power Company | Interest rate
Derivatives Fair Value [Line Items]
Derivative Liabilities		13	13
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Dominion Energy Gas Holdings, LLC
Derivatives Fair Value [Line Items]
Derivative Liabilities	[10]		4
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Dominion Energy Gas Holdings, LLC | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities			1
Fair Value - Derivatives under Hedge Accounting [Member] | Noncurrent Liabilities [Member] | Dominion Energy Gas Holdings, LLC | Foreign currency
Derivatives Fair Value [Line Items]
Derivative Liabilities			3
Derivatives Not Designated as Hedging Instruments
Derivatives Fair Value [Line Items]
Derivative Asset		253	233
Derivative Liabilities		93	44
Derivatives Not Designated as Hedging Instruments | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset		166	188
Derivative Liabilities		9	10
Derivatives Not Designated as Hedging Instruments | Current Assets
Derivatives Fair Value [Line Items]
Derivative Asset	[1]	158	101
Derivatives Not Designated as Hedging Instruments | Current Assets | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		158	101
Derivatives Not Designated as Hedging Instruments | Current Assets | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset	[2]	75	60
Derivatives Not Designated as Hedging Instruments | Current Assets | Virginia Electric and Power Company | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		75	60
Derivatives Not Designated as Hedging Instruments | Noncurrent Assets
Derivatives Fair Value [Line Items]
Derivative Asset	[3]	95	132
Derivatives Not Designated as Hedging Instruments | Noncurrent Assets | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		95	132
Derivatives Not Designated as Hedging Instruments | Noncurrent Assets | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Asset		91	128
Derivatives Not Designated as Hedging Instruments | Noncurrent Assets | Virginia Electric and Power Company | Commodity
Derivatives Fair Value [Line Items]
Derivative Asset		91	128
Derivatives Not Designated as Hedging Instruments | Current Liabilities
Derivatives Fair Value [Line Items]
Derivative Liabilities	[5]	92	41
Derivatives Not Designated as Hedging Instruments | Current Liabilities | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		92	41
Derivatives Not Designated as Hedging Instruments | Current Liabilities | Virginia Electric and Power Company
Derivatives Fair Value [Line Items]
Derivative Liabilities	[6]	9	10
Derivatives Not Designated as Hedging Instruments | Current Liabilities | Virginia Electric and Power Company | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		9	10
Derivatives Not Designated as Hedging Instruments | Noncurrent Liabilities [Member]
Derivatives Fair Value [Line Items]
Derivative Liabilities	[8]	1	3
Derivatives Not Designated as Hedging Instruments | Noncurrent Liabilities [Member] | Commodity
Derivatives Fair Value [Line Items]
Derivative Liabilities		$ 1	$ 3
[1]	Current derivative assets are presented in other current assets in Dominion Energy's Consolidated Balance Sheets.
[2]	Current derivative assets are presented in other current assets in Virginia Power's Consolidated Balance Sheets.
[3]	Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy's Consolidated Balance Sheets.
[4]	Noncurrent derivative assets are presented in other deferred charges and other assets in Dominion Energy Gas' Consolidated Balance Sheets.
[5]	Current derivative liabilities are presented in other current liabilities in Dominion Energy's Consolidated Balance Sheets.
[6]	Current derivative liabilities are presented in other current liabilities in Virginia Power's Consolidated Balance Sheets.
[7]	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's Consolidated Balance Sheets.
[9]	Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Virginia Power's Consolidated Balance Sheets.
[10]	Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy Gas' Consolidated Balance Sheets.

Derivatives and Hedge Account96

Derivatives and Hedge Accounting Activities (Gains and Losses on Derivatives in Cash Flow Hedging Relationships) (Detail) - Cash Flow Hedges - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1]	$ 11	$ 92	$ 184
Amount of Gain (Loss) Reclassified From AOCI to Income		47	259	176
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]	(58)	(26)	(9)
Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[3]	(8)	(3)	(3)
Amount of Gain (Loss) Reclassified From AOCI to Income		(1)	(1)	(1)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[4]	(58)	(26)	(9)
Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[5]	8	(26)	10
Amount of Gain (Loss) Reclassified From AOCI to Income		7	(15)	6
Commodity
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1]	1	164	230
Amount of Gain (Loss) Reclassified From AOCI to Income		79	307	187
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2]			4
Commodity | Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income				(1)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[4]			4
Commodity | Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[5]	(10)	(12)	16
Amount of Gain (Loss) Reclassified From AOCI to Income		(8)	4	6
Commodity | Operating Revenue
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income		81	330	203
Commodity | Operating Revenue | Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income		(8)	4	6
Commodity | Purchased Gas
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income		(2)	(13)	(15)
Commodity | Electric fuel and other energy-related purchases
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income			(10)	(1)
Commodity | Electric fuel and other energy-related purchases | Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Reclassified From AOCI to Income				(1)
Interest rate
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1],[6]	(8)	(66)	(46)
Amount of Gain (Loss) Reclassified From AOCI to Income	[6]	(52)	(31)	(11)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[2],[6]	(58)	(26)	(13)
Interest rate | Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[3],[7]	(8)	(3)	(3)
Amount of Gain (Loss) Reclassified From AOCI to Income	[7]	(1)	(1)
Increase (Decrease) in Derivatives Subject to Regulatory Treatment	[4],[7]	(58)	(26)	(13)
Interest rate | Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[5],[8]		(8)	$ (6)
Amount of Gain (Loss) Reclassified From AOCI to Income	[8]	(5)	(2)
Foreign currency
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[1],[9]	18	(6)
Amount of Gain (Loss) Reclassified From AOCI to Income	[9]	20	(17)
Foreign currency | Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in AOCI on Derivatives (Effective Portion)	[5],[10]	18	(6)
Amount of Gain (Loss) Reclassified From AOCI to Income	[10]	$ 20	$ (17)
[1]	Amounts deferred into AOCI have no associated effect in Dominion Energy's Consolidated Statements of Income.
[2]	Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion Energy's Consolidated Statements of Income.
[3]	Amounts deferred into AOCI have no associated effect in Virginia Power's Consolidated Statements of Income.
[4]	Represents net derivative activity deferred into and amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power's Consolidated Statements of Income.
[5]	Amounts deferred into AOCI have no associated effect in Dominion Energy Gas' Consolidated Statements of Income.
[6]	Amounts recorded in Dominion Energy's Consolidated Statements of Income are classified in interest and related charges.
[7]	Amounts recorded in Virginia Power's Consolidated Statements of Income are classified in interest and related charges.
[8]	Amounts recorded in Dominion Energy Gas' Consolidated Statements of Income are classified in interest and related charges.
[9]	Amounts recorded in Dominion Energy's Consolidated Statements of Income are classified in other income.
[10]	Amounts recorded in Dominion Energy Gas' Consolidated Statements of Income are classified in other income.

Derivatives and Hedge Account97

Derivatives and Hedge Accounting Activities (Schedule of Derivatives not Designated as Hedging Instruments) (Detail) - Derivatives Not Designated as Hedging Instruments - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[1]	$ (45)	$ (63)	$ (5)
Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[2]	(57)	(70)	(13)
Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives			1	6
Commodity | Operating Revenue
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[1]	18	2	24
Commodity | Operating Revenue | Virginia Electric and Power Company
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[2],[3]	(57)	(70)	(13)
Commodity | Operating Revenue | Dominion Energy Gas Holdings, LLC
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives			1	6
Commodity | Purchased Gas
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[1]	(3)	4	(14)
Commodity | Electric fuel and other energy-related purchases
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[1]	(59)	(70)	(14)
Commodity | Other operations and maintenance
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[1]	$ (1)	$ 1
Interest rate
Derivative Instruments Gain Loss [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	[1],[4]			$ (1)
[1]	Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Dominion Energy's Consolidated Statements of Income.
[2]	Includes derivative activity amortized out of regulatory assets/liabilities. Amounts deferred into regulatory assets/liabilities have no associated effect in Virginia Power's Consolidated Statements of Income.
[3]	Amounts recorded in Virginia Power's Consolidated Statements of Income are classified in electric fuel and other energy-related purchases.
[4]	Amounts recorded in Dominion Energy's Consolidated Statements of Income are classified in interest and related charges.

Earnings Per Share (Calculation

Earnings Per Share (Calculation of Basic and Diluted EPS) (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income attributable to Dominion Energy		$ 1,312	$ 665	$ 390	$ 632	$ 457	$ 690	$ 452	$ 524	$ 2,999	$ 2,123	$ 1,899
Average shares of common stock outstanding - Basic										636	616.4	592.4
Net effect of dilutive securities	[1]										0.7	1.3
Average shares of common stock outstanding - Diluted										636	617.1	593.7
Earnings Per Common Share - Basic		$ 2.04	$ 1.03	$ 0.62	$ 1.01	$ 0.73	$ 1.10	$ 0.73	$ 0.88	$ 4.72	$ 3.44	$ 3.21
Earnings Per Common Share - Diluted		$ 2.04	$ 1.03	$ 0.62	$ 1.01	$ 0.73	$ 1.10	$ 0.73	$ 0.88	$ 4.72	$ 3.44	$ 3.20
[1]	Dilutive securities consist primarily of the 2013 Equity Units for 2016 and 2015. See Note 17 for more information.

Investments (Narrative) (Detail

Investments (Narrative) (Detail) mi in Millions, $ in Millions		1 Months Ended				3 Months Ended								12 Months Ended
		Dec. 31, 2016USD ($)	Oct. 31, 2016USD ($)	May 31, 2016USD ($)	Sep. 30, 2014Membermi	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Equity in earnings on investments														$ (18)		$ 111		$ 56
Distributions received from investment														419		104		83
Carrying amount of investment that exceeded share of underlying equity		$ 260				$ 249				$ 260				249		260
Equity method investment goodwill		176				176				176				176		176
Additional membership percentage interest purchased			3.00%
Payment for purchase of equity interest			$ 14
Contributions to equity method affiliates														370		198		51
Liabilities, other deferred credits and other liabilities		16,424				16,631				16,424				16,631		16,424
Operating Revenue						3,210	$ 3,179	$ 2,813	$ 3,384	3,086	$ 3,132	$ 2,598	$ 2,921	12,586	[1]	11,737	[1]	11,683	[1]
Other receivables	[1]	183				126				183				126		183
Trading Securities [Member]
Schedule of Equity Method Investments [Line Items]
Rabbi trust securities		104				112				104				112		104
Dominion Energy Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings on investments														21		21		23
Liabilities, other deferred credits and other liabilities		2,863				2,866				2,863				2,866		2,863
Operating Revenue						501	$ 401	$ 422	$ 490	457	$ 382	$ 368	$ 431	1,814	[2]	1,638	[2]	1,716	[2]
Other receivables	[2]	13				15				13				15		13
Dominion Energy Gas Holdings, LLC | Partnership Interest
Schedule of Equity Method Investments [Line Items]
Equity in earnings on investments														21		21		23
Distributions received from investment														24		22		28
Carrying amount of investment that exceeded share of underlying equity		8				8				8				8		8
Dominion Energy Gas Holdings, LLC | Partnership Interest | Other Income [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of non-controlling partnership interest sold				0.65%
Sales price of non-controlling partnership interest				$ 7
Amount of gain from sale				5
Amount of after tax gain from sale				$ 3
Finite Lived Equity Method Investment Basis Difference [Member]
Schedule of Equity Method Investments [Line Items]
Carrying amount of investment that exceeded share of underlying equity		84				73				84				73		84
Blue Racer Midstream Llc [Member] | Oil and Gas Properties [Member]
Schedule of Equity Method Investments [Line Items]
Amount paid to repurchase portion of Western System from Blue Racer		10
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Distributions received from investment														270
Contributions to equity method affiliates														310		184		38
Atlantic Coast Pipeline | DETI
Schedule of Equity Method Investments [Line Items]
Operating Revenue														129		95		$ 74
Other receivables		$ 10				12				$ 10				12		$ 10
Atlantic Coast Pipeline | Pipelines | Jointly Owned Natural Gas Pipeline | Distribution
Schedule of Equity Method Investments [Line Items]
Ownership interest (percentage)			48.00%
Length of natural gas pipeline (in miles) | mi					600
Number of members | Member					3
Duration of contract					20 years
Atlantic Coast Pipeline | Pipelines | Jointly Owned Natural Gas Pipeline | Distribution | Duke Energy
Schedule of Equity Method Investments [Line Items]
Ownership interest (percentage)			47.00%
Atlantic Coast Pipeline | Pipelines | Jointly Owned Natural Gas Pipeline | Distribution | Southern Company Gas [Member]
Schedule of Equity Method Investments [Line Items]
Ownership interest (percentage)			5.00%
Nedpower Mount Storm Llc [Member]
Schedule of Equity Method Investments [Line Items]
Liabilities, other deferred credits and other liabilities						17								17
Nedpower Mount Storm Llc [Member] | Property, Plant and Equipment [Member]
Schedule of Equity Method Investments [Line Items]
Impairment charge						126
Impairment charge, after tax						76
Fowler I Holdings LLC
Schedule of Equity Method Investments [Line Items]
Impairment charge						32
Impairment charge, after tax						20
Fair value of investment						$ 81								$ 81
[1]	See Note 9 for amounts attributable to related parties.
[2]	See Note 24 for amounts attributable to related parties.

Investments (Marketable Equity

Investments (Marketable Equity and Debt Securities and Cash Equivalents (Classified as Available-for-sale) and Cost Method Investments in Decommissioning Trust Funds) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Amortized Cost, Total		$ 3,200	$ 3,053
Total Unrealized Gains	[1]	1,899	1,443
Total Unrealized Losses	[1],[2]	(6)	(12)
Fair Value		5,093	4,484
Cash Equivalents and Other [Member]
Investment Holdings [Line Items]
Amortized Cost, Total	[3]	34	12
Fair Value	[3]	34	12
Cost Method Investments [Member]
Investment Holdings [Line Items]
Amortized Cost, Total		68	69
Fair Value		68	69
Common/collective trust funds
Investment Holdings [Line Items]
Amortized Cost, Total		60	67
Fair Value		60	67
Virginia Electric and Power Company
Investment Holdings [Line Items]
Amortized Cost, Total		1,549	1,473
Total Unrealized Gains	[1]	852	639
Total Unrealized Losses	[1],[4]	(2)	(6)
Fair Value		2,399	2,106
Virginia Electric and Power Company | Cash Equivalents and Other [Member]
Investment Holdings [Line Items]
Amortized Cost, Other Investments	[5]	22	7
Fair Value	[5]	22	7
Virginia Electric and Power Company | Cost Method Investments [Member]
Investment Holdings [Line Items]
Amortized Cost, Other Investments		68	69
Fair Value		68	69
Virginia Electric and Power Company | Common/collective trust funds
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities		27	26
Fair Value		27	26
Corporate debt instruments
Investment Holdings [Line Items]
Amortized Cost, Total		430	478
Total Unrealized Gains	[1]	15	13
Total Unrealized Losses	[1]	(1)	(4)
Fair Value		444	487
Corporate debt instruments | Virginia Electric and Power Company
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities		216	274
Total Unrealized Gains	[1]	8	6
Total Unrealized Losses	[1]		(4)
Fair Value		224	276
Government Securities [Member]
Investment Holdings [Line Items]
Amortized Cost, Total		1,039	978
Total Unrealized Gains	[1]	27	22
Total Unrealized Losses	[1]	(5)	(8)
Fair Value		1,061	992
Government Securities [Member] | Virginia Electric and Power Company
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities		482	420
Total Unrealized Gains	[1]	13	9
Total Unrealized Losses	[1]	(2)	(2)
Fair Value		493	427
U.S. | Equity securities:
Investment Holdings [Line Items]
Amortized Cost, Total		1,569	1,449
Total Unrealized Gains	[1]	1,857	1,408
Fair Value		3,426	2,857
U.S. | Equity securities: | Virginia Electric and Power Company
Investment Holdings [Line Items]
Amortized Cost, Marketable Securities		734	677
Total Unrealized Gains	[1]	831	624
Fair Value		$ 1,565	$ 1,301
[1]	Included in AOCI and the nuclear decommissioning trust regulatory liability as discussed in Note 2.
[2]	The fair value of securities in an unrealized loss position was $565 million and $576 million at December 31, 2017 and 2016, respectively.
[3]	Includes pending sales of securities of $5 million and $9 million at December 31, 2017 and 2016, respectively.
[4]	The fair value of securities in an unrealized loss position was $234 million and $287 million at December 31, 2017 and 2016, respectively.
[5]	Includes pending sales of securities of $6 million and $7 million at December 31, 2017 and 2016, respectively.

Investments (Marketable Equi101

Investments (Marketable Equity and Debt Securities and Cash Equivalents (Classified as Available-for-sale) and Cost Method Investments in Decommissioning Trust Funds) (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Investment Holdings [Line Items]
Net assets related to pending sales and purchases of securities	$ 5	$ 9
Fair value of securities in an unrealized loss position	565	576
Virginia Electric and Power Company
Investment Holdings [Line Items]
Net assets related to pending sales and purchases of securities	6	7
Fair value of securities in an unrealized loss position	$ 234	$ 287

Investments (Fair Value of our

Investments (Fair Value of our Marketable Debt Securities by Contractual Maturity) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Due in one year or less	$ 151
Due after one year through five years	385
Due after five years through ten years	370
Due after ten years	659
Total	1,565
Virginia Electric and Power Company
Schedule of Held-to-maturity Securities [Line Items]
Due in one year or less	32
Due after one year through five years	165
Due after five years through ten years	199
Due after ten years	348
Total	$ 744

Investments (Selected Informati

Investments (Selected Information Regarding Marketable Equity and Debt Securities) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales		$ 1,831	$ 1,422	$ 1,340
Realized gains	[1]	166	128	219
Realized losses	[1]	71	55	84
Virginia Electric and Power Company
Schedule of Available-for-sale Securities [Line Items]
Proceeds from sales		849	733	639
Realized gains	[1]	75	63	110
Realized losses	[1]	$ 30	$ 27	$ 43
[1]	Includes realized gains and losses recorded to the nuclear decommissioning trust regulatory liability as discussed in Note 2.

Investments (Recorded Other-Tha

Investments (Recorded Other-Than-Temporary Impairment Losses on Investments) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Total other-than-temporary impairment losses	[1]	$ 44	$ 51	$ 66
Losses recorded to the nuclear decomissioning trust regulatory liability		(16)	(16)	(26)
Losses recognized in other comprehensive income (before taxes)		(5)	(12)	(9)
Net impairment losses recognized in earnings		23	23	31
Virginia Electric and Power Company
Schedule of Available-for-sale Securities [Line Items]
Total other-than-temporary impairment losses	[2]	20	26	36
Losses recorded to the nuclear decomissioning trust regulatory liability		(16)	(16)	(26)
Losses recognized in other comprehensive income (before taxes)		(2)	(7)	(6)
Net impairment losses recognized in earnings		$ 2	$ 3	$ 4
[1]	Amounts include other-than-temporary impairment losses for debt securities of $5 million, $13 million and $9 million at December 31, 2017, 2016 and 2015, respectively.
[2]	Amounts include other-than-temporary impairment losses for debt securities of $2 million, $8 million and $6 million at December 31, 2017, 2016 and 2015, respectively.

Investments (Recorded Other-105

Investments (Recorded Other-Than-Temporary Impairment Losses on Investments) (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Other-than-temporary impairment losses for debt securities	$ 5	$ 13	$ 9
Virginia Electric and Power Company
Schedule of Available-for-sale Securities [Line Items]
Other-than-temporary impairment losses for debt securities	$ 2	$ 8	$ 6

Investments (Investments Under

Investments (Investments Under Equity Method of Accounting) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,544	$ 1,561	$ 1,320
Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	$ 311	316
Description	Gas transmission system
Blue Racer Midstream Llc [Member]
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	$ 691	677
Description	Midstream gas and related services
Atlantic Coast Pipeline
Schedule of Equity Method Investments [Line Items]
Ownership%	48.00%
Investment Balance	$ 382	256
Description	Gas transmission system
Fowler I Holdings LLC
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	$ 81	116
Description	Wind-powered merchant generation facility
Nedpower Mount Storm Llc [Member]
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance		112
Description	Wind-powered merchant generation facility
Other Investment [Member]
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 79	84
Dominion Energy Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 95	98	$ 102
Dominion Energy Gas Holdings, LLC | Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	24.07%
Investment Balance	$ 95	$ 98
Description	Gas transmission system

Investments (Investments Und107

Investments (Investments Under Equity Method of Accounting) (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2015
Schedule of Equity Method Investments [Line Items]
Liabilities, other deferred credits and other liabilities	$ 16,631	$ 16,424
Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Nedpower Mount Storm Llc [Member]
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Liabilities, other deferred credits and other liabilities	$ 17
Dominion Energy Midstream Partners, LP | Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	25.93%		25.93%
Dominion Energy Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Liabilities, other deferred credits and other liabilities	$ 2,866	$ 2,863
Dominion Energy Gas Holdings, LLC | Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	24.07%

Property, Plant and Equipmen108

Property, Plant and Equipment (Property, Plant and Equipment) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Utility:
Generation	$ 17,602	$ 17,147
Transmission	15,335	14,315
Distribution	17,408	16,381
Storage	2,887	2,814
Nuclear fuel	1,599	1,537
Gas gathering and processing	219	216
Oil and gas	1,720	1,652
General and other	1,514	1,450
Plant under construction	7,765	6,254
Total utility	66,049	61,766
Nonutility:
Merchant generation-nuclear	1,452	1,419
Merchant generation-other	4,992	4,149
Nuclear fuel	968	897
Gas Gathering and Processing	630	619
Other-including plant under construction	732	706
Total nonutility	8,774	7,790
Total property, plant and equipment	74,823	69,556
Virginia Electric and Power Company
Utility:
Generation	17,602	17,147
Transmission	8,332	7,871
Distribution	11,151	10,573
Nuclear fuel	1,599	1,537
General and other	794	745
Plant under construction	2,840	2,146
Total utility	42,318	40,019
Nonutility:
Other-including plant under construction	11	11
Total property, plant and equipment	42,329	40,030
Dominion Energy Gas Holdings, LLC
Utility:
Transmission	4,732	4,231
Distribution	3,267	3,019
Storage	1,688	1,627
Gas gathering and processing	202	198
General and other	216	184
Plant under construction	293	448
Total utility	10,398	9,707
Nonutility:
Gas Gathering and Processing	630	619
Other-including plant under construction	145	149
Total nonutility	775	768
Total property, plant and equipment	$ 11,173	$ 10,475

Property, Plant and Equipmen109

Property, Plant and Equipment (Share of Jointly-Owned Power Stations) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Millstone Unit [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	93.50%	[1]
Plant in service	$ 1,217	[1]
Accumulated depreciation	(381)	[1]
Nuclear fuel	552	[1]
Accumulated amortization of nuclear fuel	(427)	[1]
Plant under construction	$ 68	[1]
Virginia Electric and Power Company | Bath Country Pumped Storage Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	60.00%	[2]
Plant in service	$ 1,059	[2]
Accumulated depreciation	(612)	[2]
Plant under construction	$ 2	[2]
Virginia Electric and Power Company | North Anna
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	88.40%	[2]
Plant in service	$ 2,504	[2]
Accumulated depreciation	(1,263)	[2]
Nuclear fuel	745	[2]
Accumulated amortization of nuclear fuel	(607)	[2]
Plant under construction	$ 92	[2]
Virginia Electric and Power Company | Clover Power Station [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	50.00%	[2]
Plant in service	$ 589	[2]
Accumulated depreciation	(231)	[2]
Plant under construction	$ 6	[2]
[1]	Unit jointly owned by Dominion Energy.
[2]	Units jointly owned by Virginia Power.

Property, Plant and Equipmen110

Property, Plant and Equipment (Narrative) (Detail) $ in Millions

1 Months Ended

3 Months Ended

12 Months Ended

Jan. 31, 2018USD ($)a

Dec. 31, 2017USD ($)

Sep. 30, 2017Project

Aug. 31, 2017USD ($)a

Jul. 31, 2017USD ($)a

Mar. 31, 2017USD ($)

Apr. 30, 2016USD ($)a

Sep. 30, 2015USD ($)aFields

Mar. 31, 2015USD ($)a

Dec. 31, 2014USD ($)

Nov. 30, 2014USD ($)aFields

Sep. 30, 2018USD ($)

Dec. 31, 2017USD ($)

Sep. 30, 2017USD ($)

Dec. 31, 2019USD ($)MW

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)a

Dec. 31, 2015USD ($)

Dec. 31, 2013USD ($)a

Oct. 31, 2017USD ($)

Property, Plant and Equipment [Line Items]

Project Cost

$ 405

$ 40

$ 418

Retail Energy Marketing Assets | Disposal Group, Disposed of by Sale, Not Discontinued Operations

Property, Plant and Equipment [Line Items]

Amount of consideration

$ 143

Gain from sale

$ 78

After tax gain on sale

$ 48

Contractual term of agreement to use brand

10 years

Retail Energy Marketing Assets | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Scenario, Forecast

Property, Plant and Equipment [Line Items]

Expected benefit to be recognized

$ 65

Expected benefit to be recognized, net of tax

48

Retail Energy Marketing Assets | Disposal Group, Disposed of by Sale, Not Discontinued Operations | First Phase of Agreements to Sell Certain Assets

Property, Plant and Equipment [Line Items]

Amount of consideration

$ 79

$ 79

79

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member]

Property, Plant and Equipment [Line Items]

Amount of consideration

$ 5

$ 120

$ 10

$ 200

Number of natural gas producers

2

Development rights (number of acres) | a

2,000

11,000

24,000

4,000

100,000

Period for payments related to conveyance of natural gas storage fields

4 years

9 years

Proceeds from assignment of Shale Development Rights

$ 27

$ 16

$ 60

$ 100

Gas and oil area developed net remaining interest conveyed percentage

50.00%

50.00%

50.00%

Number of natural gas storage fields | Fields

1

Number of acres included in initial conveyance | a

12,000

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member] | Other operations and maintenance

Property, Plant and Equipment [Line Items]

Gain from sale

$ 5

27

$ 10

After tax gain on sale

$ 3

$ 16

6

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member] | Amended Agreement to Extend Conveyance of Development Rights [Member]

Property, Plant and Equipment [Line Items]

Development rights (number of acres) | a

70,000

70,000

Period for payments related to conveyance of natural gas storage fields

2 years

Development rights conveyed (number of acres) | a

9,000

Partial interest percentage conveyed

32.00%

Gas and oil area developed net remaining interest conveyed percentage

68.00%

Total consideration

$ 130

65

Gain from sale

$ 56

After tax gain on sale

33

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member] | Amended Agreement to Extend Conveyance of Development Rights [Member] | Royalty Interest

Property, Plant and Equipment [Line Items]

Gain from sale

9

After tax gain on sale

$ 5

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member] | Amended Agreement to Extend Conveyance of Development Rights [Member] | Final Conveyance

Property, Plant and Equipment [Line Items]

Gain from sale

65

After tax gain on sale

$ 47

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member] | Amended Agreement to Extend Conveyance of Development Rights [Member] | Scenario, Forecast

Property, Plant and Equipment [Line Items]

Total consideration

$ 65

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Oil and Gas Properties [Member] | Amended Agreement to Extend Conveyance of Development Rights [Member] | Other operations and maintenance

Property, Plant and Equipment [Line Items]

Revenue recognized

$ 35

$ 43

Revenue recognized net of tax

$ 21

$ 27

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Subsequent Event | Oil and Gas Properties [Member]

Property, Plant and Equipment [Line Items]

Amount of consideration

$ 28

Development rights (number of acres) | a

18,000

Gas and oil area developed net remaining interest conveyed percentage

50.00%

Dominion Energy Gas Holdings, LLC | Marcellus Shale [Member] | Subsequent Event | Oil and Gas Properties [Member] | Other operations and maintenance

Property, Plant and Equipment [Line Items]

Gain from sale

$ 28

After tax gain on sale

$ 20

Dominion Energy Gas Holdings, LLC | Uticaand Point Pleasant Shale [Member] | Oil and Gas Properties [Member]

Property, Plant and Equipment [Line Items]

Amount of consideration

$ 52

Development rights (number of acres) | a

16,000

Proceeds from assignment of Shale Development Rights

$ 52

Number of natural gas storage fields | Fields

1

Dominion Energy Gas Holdings, LLC | Uticaand Point Pleasant Shale [Member] | Oil and Gas Properties [Member] | Other operations and maintenance

Property, Plant and Equipment [Line Items]

Gain from sale

$ 52

After tax gain on sale

$ 29

Virginia Electric and Power Company

Property, Plant and Equipment [Line Items]

Project Cost

$ 41

$ 7

$ 43

Virginia Electric and Power Company | Two Solar Development Projects

Property, Plant and Equipment [Line Items]

Number of Projects | Project

2

Virginia Electric and Power Company | Scenario, Forecast | Two Solar Development Projects

Property, Plant and Equipment [Line Items]

MW Capacity | MW

155

Virginia Electric and Power Company | Scenario, Forecast | First Solar Development Project

Property, Plant and Equipment [Line Items]

Project Cost

$ 140

Virginia Electric and Power Company | Scenario, Forecast | Second Solar Development Project

Property, Plant and Equipment [Line Items]

Project Cost

$ 140

Virginia Electric and Power Company | Rental Portfolio of Electric Transmission Towers [Member] | Disposal Group, Disposed of by Sale, Not Discontinued Operations

Property, Plant and Equipment [Line Items]

Amount of consideration

$ 91

Amount recognized in other income from sale

11

Amount to be recognized in other income ratably through 2023

$ 35

Goodwill and Intangible Asse111

Goodwill and Intangible Assets (Goodwill) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	$ 6,399	$ 3,294
Dominion Questar Combination		6
Goodwill, Ending Balance	[1]	6,405	6,399
Dominion Energy Gas Holdings, LLC
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	542	542
No events affecting goodwill		0	0
Goodwill, Ending Balance	[1]	542	542
Dominion Questar Corporation
Goodwill [Roll Forward]
Dominion Questar Combination			3,105
Operating Segments | Power Generation
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	1,422	1,422
Goodwill, Ending Balance	[1]	1,422	1,422
Operating Segments | Power Generation | Dominion Energy Gas Holdings, LLC
Goodwill [Roll Forward]
No events affecting goodwill		0	0
Operating Segments | Gas Infrastructure
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	4,051	946
Dominion Questar Combination		6
Goodwill, Ending Balance	[1]	4,057	4,051
Operating Segments | Gas Infrastructure | Dominion Energy Gas Holdings, LLC
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	542	542
No events affecting goodwill		0	0
Goodwill, Ending Balance	[1]	542	542
Operating Segments | Power Delivery
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	926	926
Goodwill, Ending Balance	[1]	926	926
Operating Segments | Power Delivery | Dominion Energy Gas Holdings, LLC
Goodwill [Roll Forward]
No events affecting goodwill		0	0
Operating Segments | Corporate and Other | Dominion Energy Gas Holdings, LLC
Goodwill [Roll Forward]
No events affecting goodwill	[2]	$ 0	0
Operating Segments | Dominion Questar Corporation | Gas Infrastructure
Goodwill [Roll Forward]
Dominion Questar Combination	[3]		$ 3,105
[1]	Goodwill amounts do not contain any accumulated impairment losses.
[2]	Goodwill recorded at the Corporate and Other segment is allocated to the primary operating segments for goodwill impairment testing purposes.
[3]	See Note 3.

Goodwill and Intangible Asse112

Goodwill and Intangible Assets (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Amortization expense for intangible assets	$ 80	$ 73	$ 78
Acquisition of intangible assets	$ 147
Weighted-average amortization period (years)	14 years
Virginia Electric and Power Company
Goodwill [Line Items]
Amortization expense for intangible assets	$ 31	29	25
Acquisition of intangible assets	$ 39
Weighted-average amortization period (years)	7 years
Dominion Energy Gas Holdings, LLC
Goodwill [Line Items]
Amortization expense for intangible assets	$ 14	$ 6	$ 18
Acquisition of intangible assets	$ 25
Weighted-average amortization period (years)	14 years

Goodwill and Intangible Asse113

Goodwill and Intangible Assets (Components of Intangible Assets) (Detail) - Computer Software, Intangible Asset [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,043	$ 955
Accumulated Amortization	358	337
Virginia Electric and Power Company
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	347	326
Accumulated Amortization	114	101
Dominion Energy Gas Holdings, LLC
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	165	147
Accumulated Amortization	$ 56	$ 49

Goodwill and Intangible Asse114

Goodwill and Intangible Assets (Annual Amortization Expense of Intangible Assets) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
2,018	$ 78
2,019	68
2,020	56
2,021	43
2,022	37
Virginia Electric and Power Company
Finite-Lived Intangible Assets [Line Items]
2,018	30
2,019	26
2,020	20
2,021	13
2,022	9
Dominion Energy Gas Holdings, LLC
Finite-Lived Intangible Assets [Line Items]
2,018	13
2,019	13
2,020	12
2,021	11
2,022	$ 10

Regulatory Assets and Liabil115

Regulatory Assets and Liabilities (Schedule of Regulatory Assets) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Regulatory Assets [Line Items]
Regulatory assets-current		$ 294	$ 244
Regulatory assets-noncurrent		2,480	2,473
Total regulatory assets		2,774	2,717
Deferred nuclear refueling outage costs
Regulatory Assets [Line Items]
Regulatory assets-current	[1]	54	71
Deferred rate adjustment clause costs
Regulatory Assets [Line Items]
Regulatory assets-current	[2]	70	63
Regulatory assets-noncurrent	[2]	401	329
Deferred cost of fuel used in electric generation
Regulatory Assets [Line Items]
Regulatory assets-current	[3]	23
Unrecovered gas costs
Regulatory Assets [Line Items]
Regulatory assets-current	[4]	38	19
Other
Regulatory Assets [Line Items]
Regulatory assets-current		109	91
Regulatory assets-noncurrent		119	155
Unrecognized pension and other postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[5]	1,336	1,401
Derivatives
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[6]	223	174
PJM transmission rates
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[7]	222	192
Income taxes recoverable through future rates
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[8]	32	123
Utility reform legislation
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[9]	$ 147	99
Maximum | Deferred nuclear refueling outage costs
Regulatory Assets [Line Items]
Amortization period for deferred costs		18 months
Virginia Electric and Power Company
Regulatory Assets [Line Items]
Regulatory assets-current		$ 205	179
Regulatory assets-noncurrent		810	770
Total regulatory assets		1,015	949
Virginia Electric and Power Company | Deferred nuclear refueling outage costs
Regulatory Assets [Line Items]
Regulatory assets-current	[1]	54	71
Virginia Electric and Power Company | Deferred rate adjustment clause costs
Regulatory Assets [Line Items]
Regulatory assets-current	[2]	56	51
Regulatory assets-noncurrent	[2]	312	246
Virginia Electric and Power Company | Deferred cost of fuel used in electric generation
Regulatory Assets [Line Items]
Regulatory assets-current	[3]	23
Virginia Electric and Power Company | Other
Regulatory Assets [Line Items]
Regulatory assets-current		72	57
Regulatory assets-noncurrent		86	123
Virginia Electric and Power Company | Derivatives
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[6]	190	133
Virginia Electric and Power Company | PJM transmission rates
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[7]	222	192
Virginia Electric and Power Company | Income taxes recoverable through future rates
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[8]		76
Dominion Energy Gas Holdings, LLC
Regulatory Assets [Line Items]
Regulatory assets-current	[10]	26	26
Regulatory assets-noncurrent		511	577
Total regulatory assets		537	603
Dominion Energy Gas Holdings, LLC | Deferred rate adjustment clause costs
Regulatory Assets [Line Items]
Regulatory assets-current	[2]	14	12
Regulatory assets-noncurrent	[2]	89	79
Dominion Energy Gas Holdings, LLC | Unrecovered gas costs
Regulatory Assets [Line Items]
Regulatory assets-current	[4]	8	12
Dominion Energy Gas Holdings, LLC | Other
Regulatory Assets [Line Items]
Regulatory assets-current		4	2
Regulatory assets-noncurrent		17	18
Dominion Energy Gas Holdings, LLC | Unrecognized pension and other postretirement benefit costs
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[5]	258	358
Dominion Energy Gas Holdings, LLC | Income taxes recoverable through future rates
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[8]		23
Dominion Energy Gas Holdings, LLC | Utility reform legislation
Regulatory Assets [Line Items]
Regulatory assets-noncurrent	[9]	$ 147	$ 99
[1]	Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months.
[2]	Primarily reflects deferrals under the electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects for Virginia Power and deferrals of costs associated with certain current and prospective rider projects for Dominion Energy Gas. See Note 13 for more information.
[3]	Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Dominion Energy's and Virginia Power's generation operations. See Note 13 for more information.
[4]	Reflects unrecovered gas costs at regulated gas operations, which are recovered through filings with the applicable regulatory authority.
[5]	Represents unrecognized pension and other postretirement employee benefit costs expected to be recovered through future rates generally over the expected remaining service period of plan participants by certain of Dominion Energy's and Dominion Energy Gas' rate-regulated subsidiaries.
[6]	As discussed under Derivative Instruments in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers.
[7]	Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information.
[8]	Amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity and depreciation of property, plant and equipment for which deferred income taxes were not recognized for ratemaking purposes, including amounts attributable to tax rate changes. See below for discussion of the 2017 Tax Reform Act.
[9]	Ohio legislation under House Bill 95, which became effective in September 2011. This law updates natural gas legislation by enabling gas companies to include more up-to-date cost levels when filing rate cases. It also allows gas companies to seek approval of capital expenditure plans under which gas companies can recognize carrying costs on associated capital investments placed in service and can defer the carrying costs plus depreciation and property tax expenses for recovery from ratepayers in the future.
[10]	Current regulatory assets are presented in other current assets in the Consolidated Balance Sheets of Dominion Energy Gas.

Regulatory Assets and Liabil116

Regulatory Assets and Liabilities (Schedule of Regulatory Liabilities) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[1]	$ 193	$ 163
Regulatory liabilities-noncurrent		6,916	2,622
Total regulatory liabilities		7,109	2,785
Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[1]	127	115
Regulatory liabilities-noncurrent		4,760	1,962
Total regulatory liabilities		4,887	2,077
Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[1]	38	35
Regulatory liabilities-noncurrent		1,227	219
Total regulatory liabilities		1,265	254
Provision for future cost of removal and AROs
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[2]	101
Regulatory liabilities-noncurrent	[2]	1,384	1,427
Provision for future cost of removal and AROs | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[2]	13
Regulatory liabilities-noncurrent	[2]	160	174
PIPP [Member]
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[3]	20	28
PIPP [Member] | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[3]	20	28
Deferred cost of fuel used in electric generation
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[4]	8	61
Deferred cost of fuel used in electric generation | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[4]	8	61
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		64	74
Regulatory liabilities-noncurrent		284	224
Other | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		39	54
Regulatory liabilities-noncurrent		74	45
Other | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-current		5	7
Regulatory liabilities-noncurrent		69	45
Income taxes recoverable through future rates
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[5]	4,058
Income taxes recoverable through future rates | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[5]	2,581
Income taxes recoverable through future rates | Dominion Energy Gas Holdings, LLC
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[5]	998
Nuclear decommissioning trust
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[6]	1,121	902
Nuclear decommissioning trust | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[6]	1,121	902
Derivatives
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[7]	69	69
Derivatives | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-noncurrent	[7]	69	69
Provision for future cost of removal | Virginia Electric and Power Company
Regulatory Liabilities [Line Items]
Regulatory liabilities-current	[2]	80
Regulatory liabilities-noncurrent	[2]	$ 915	$ 946
[1]	Current regulatory liabilities are presented in other current liabilities in the Consolidated Balance Sheets of the Companies.
[2]	Rates charged to customers by the Companies' regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement.
[3]	Under PIPP, eligible customers can make reduced payments based on their ability to pay. The difference between the customer's total bill and the PIPP plan amount is deferred and collected or returned annually under the PIPP rate adjustment clause according to East Ohio tariff provisions. See Note 13 for more information.
[4]	Reflects deferred fuel expenses for the Virginia and North Carolina jurisdictions of Dominion Energy's and Virginia Power's generation operations. See Note 13 for more information.
[5]	Amounts recorded to pass the effect of reduced income tax rates from the 2017 Tax Reform Act to customers in future periods, which will reverse at the weighted average tax rate that was used to build the reserves over the remaining book life of the property, net of amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity.
[6]	Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon) for the future decommissioning of Virginia Power's utility nuclear generation stations, in excess of the related AROs.
[7]	As discussed under Derivative Instruments in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers.

Regulatory Assets and Liabil117

Regulatory Assets and Liabilities (Narrative) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Public Utilities, General Disclosures [Line Items]
Regulatory assets past expenditures not earning return		$ 390
Regulatory assets		$ 2,480	$ 2,473
Period for which expenditures are expected to be recovered		2 years
PJM transmission rates
Public Utilities, General Disclosures [Line Items]
Regulatory assets	[1]	$ 222	192
Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Regulatory assets past expenditures not earning return		273
Regulatory assets		810	770
Virginia Electric and Power Company | PJM transmission rates
Public Utilities, General Disclosures [Line Items]
Regulatory assets	[1]	222	192
Dominion Energy Gas Holdings, LLC
Public Utilities, General Disclosures [Line Items]
Regulatory assets past expenditures not earning return		11
Regulatory assets		$ 511	$ 577
[1]	Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information.

Regulatory Matters (Narrative)

Regulatory Matters (Narrative) (Detail) Customer in Millions

1 Months Ended

12 Months Ended

Feb. 28, 2018USD ($)

Dec. 31, 2017USD ($)kVmi

Nov. 30, 2017USD ($)kVmi

Oct. 31, 2017USD ($)Program

Sep. 30, 2017USD ($)kVmi

Aug. 31, 2017USD ($)

Jul. 31, 2017USD ($)

Jun. 30, 2017USD ($)kVmi

May 31, 2017USD ($)

Apr. 30, 2017USD ($)

Mar. 31, 2017USD ($)MW

Feb. 28, 2017USD ($)MW

Dec. 31, 2016USD ($)Rate

Nov. 30, 2016USD ($)Rate

Aug. 31, 2016kVmi

Jun. 30, 2016USD ($)

Mar. 31, 2016USD ($)kVmi

Nov. 30, 2015USD ($)kVmi

Mar. 31, 2015USD ($)

Nov. 30, 2013kVmi

Aug. 31, 2009kV

Apr. 30, 2008

Dec. 31, 2007Customer

Apr. 30, 2007kV

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)Power_Station

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Jan. 31, 2017USD ($)

Public Utilities, General Disclosures [Line Items]

Regulatory assets-noncurrent

$ 2,480,000,000

$ 2,473,000,000

$ 2,480,000,000

$ 2,473,000,000

Total amount of credit to customers

7,109,000,000

2,785,000,000

7,109,000,000

2,785,000,000

Project Cost

405,000,000

40,000,000

$ 418,000,000

PJM transmission rates

Public Utilities, General Disclosures [Line Items]

Regulatory assets-noncurrent

[1]

222,000,000

192,000,000

222,000,000

192,000,000

Virginia Electric and Power Company

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

11.40%

Regulatory assets-noncurrent

810,000,000

770,000,000

810,000,000

770,000,000

Total amount of credit to customers

4,887,000,000

2,077,000,000

4,887,000,000

2,077,000,000

Project Cost

41,000,000

7,000,000

$ 43,000,000

Virginia Electric and Power Company | PJM transmission rates

Public Utilities, General Disclosures [Line Items]

Regulatory assets-noncurrent

[1]

222,000,000

192,000,000

222,000,000

192,000,000

Virginia Electric and Power Company | Minimum

Public Utilities, General Disclosures [Line Items]

Facility operating capacity (kV) | kV

500

Virginia Electric and Power Company | Minimum | Judicial Ruling [Member]

Public Utilities, General Disclosures [Line Items]

Facility operating capacity (kV) | kV

500

Virginia Electric and Power Company | Virginia Regulation

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

$ 625,000,000

Capacity of transmission line (kV) | kV

230

Obligated to make payments to fund improvement for historical and cultural resources

$ 90,000,000

Payments made to fund improvement for historical and cultural resources

$ 90,000,000

90,000,000

Virginia Electric and Power Company | Virginia Regulation | North Anna

Public Utilities, General Disclosures [Line Items]

Period of notice of intent to sue

60 days

Virginia Electric and Power Company | Virginia Regulation | Solar Development Project

Public Utilities, General Disclosures [Line Items]

Project Cost

$ 45,000,000

Capacity of solar facility (in MW) | MW

20

Virginia Electric and Power Company | Virginia Regulation | Transmission Line between Remington and Gordonsville Substations

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

38

Capacity of transmission line (kV) | kV

230

Total estimated cost of project

$ 105,000,000

Virginia Electric and Power Company | Virginia Regulation | Idylwood substation

Public Utilities, General Disclosures [Line Items]

Total estimated cost of project

$ 110,000,000

Virginia Electric and Power Company | Virginia Regulation | Transmission Component of Virginia Power's

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

490,000,000

Virginia Electric and Power Company | Virginia Regulation | Surry Switching Station Transmission Line

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

7

Capacity of transmission line (kV) | kV

500

Virginia Electric and Power Company | Virginia Regulation | Transmission Line from Skiffes Creek Switching Station to Wheaton Substation

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

20

Capacity of transmission line (kV) | kV

230

Virginia Electric and Power Company | Virginia Regulation | Transmission Line Near Gainesville Substation And Haymarket Substation

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

5

Capacity of transmission line (kV) | kV

230

Total estimated cost of project

$ 55,000,000

Virginia Electric and Power Company | Virginia Regulation | Double Circuit Transmission Line Between Near Gainesville Substation And Haymarket Substation

Public Utilities, General Disclosures [Line Items]

Capacity of transmission line (kV) | kV

230

Virginia Electric and Power Company | Virginia Regulation | Transmission Line Between Cunningham Switching Station And Dooms Substation

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

33

Capacity of transmission line (kV) | kV

500

Total estimated cost of project

$ 60,000,000

Virginia Electric and Power Company | Virginia Regulation | Transmission Line Between Carson Switching Station A Terminus Near Rogers Road Switching Station

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

28

Capacity of transmission line (kV) | kV

500

Total estimated cost of project

$ 55,000,000

Virginia Electric and Power Company | Virginia Regulation | Transmission Lines Between Possum Point Switching Station And Novec's Smoketown Delivery Point [Member]

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

9

Capacity of transmission line (kV) | kV

115

Total estimated cost of project

$ 20,000,000

Virginia Electric and Power Company | Virginia Regulation | Transmission Line Between Dooms Substation And The Valley Substation [Member]

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

18

Capacity of transmission line (kV) | kV

500

Total estimated cost of project

$ 65,000,000

Virginia Electric and Power Company | Virginia Regulation | Transmission Line Between The Idylwood And Tysons Substations [Member]

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

4

Capacity of transmission line (kV) | kV

230

Total estimated cost of project

$ 125,000,000

Virginia Electric and Power Company | Virginia Regulation | Transmission Line Between Harmony Village Substation and White Stone Substation

Public Utilities, General Disclosures [Line Items]

Length of kV line (miles) | mi

2

Capacity of transmission line (kV) | kV

115

Total estimated cost of project

$ 85,000,000

$ 85,000,000

Virginia Electric and Power Company | Virginia Regulation | Annual Fuel Factor Submitted To The Virginia Commission

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

1,600,000,000

Increase (decrease) in revenue requirement

279,000,000

Virginia Electric and Power Company | Virginia Regulation | February 2015 Regulation Act Legislation

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

9.20%

10.50%

Virginia Electric and Power Company | Virginia Regulation | Rider S

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.40%

Approved revenue required

$ 243,000,000

Virginia Electric and Power Company | Virginia Regulation | Rider W

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.40%

Approved revenue required

$ 121,000,000

Virginia Electric and Power Company | Virginia Regulation | Rider B

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

11.40%

Proposed revenue requirement

42,000,000

Increase (decrease) in revenue requirement

$ 15,000,000

Approved revenue required

$ 27,000,000

Number of power stations converted to biomass | Power_Station

3

Virginia Electric and Power Company | Virginia Regulation | Rider U

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

9.40%

Approved revenue required

$ 22,000,000

Projected capital investment

40,000,000

Virginia Electric and Power Company | Virginia Regulation | Riders C1A and C2A

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

9.40%

Approved revenue required

$ 28,000,000

Virginia Electric and Power Company | Virginia Regulation | Riders C1A and C2A | Energy Efficiency Program

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

$ 31,000,000

Increase (decrease) in revenue requirement

$ 3,000,000

Period for cost cap

5 years

Amount of cost recovery

$ 25,000,000

Number of new energy efficiency programs | Program

1

Virginia Electric and Power Company | Virginia Regulation | Rider BW

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.40%

Proposed revenue requirement

$ 132,000,000

Increase (decrease) in revenue requirement

5,000,000

Approved revenue required

127,000,000

Virginia Electric and Power Company | Virginia Regulation | Rider US-2

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

9.40%

Proposed revenue requirement

15,000,000

Increase (decrease) in revenue requirement

5,000,000

Approved revenue required

$ 10,000,000

Virginia Electric and Power Company | Virginia Regulation | Virginia Commission 2015 Biennial Review

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.00%

Earned ROE percentage

10.89%

ROE above authorized ROE (basis points)

0.70%

Duration excess earnings will be credited to customers

6 months

Period after Biennial Review Order

60 days

Virginia Electric and Power Company | Virginia Regulation | Virginia Commission 2015 Biennial Review | Revenue Subject to Refund

Public Utilities, General Disclosures [Line Items]

Total amount of credit to customers

$ 20,000,000

Virginia Electric and Power Company | Virginia Regulation | Application filed with Virginia Commission to Construct and Operate the Oceana Solar Facility | Solar Development Project

Public Utilities, General Disclosures [Line Items]

Project Cost

$ 40,000,000

Capacity of solar facility (in MW) | MW

18

Virginia Electric and Power Company | Virginia Regulation | Rider T1

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

135,000,000

Increase (decrease) in revenue requirement

$ (55,000,000)

Virginia Electric and Power Company | Virginia Regulation | Rider R

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.40%

Approved revenue required

$ 72,000,000

Virginia Electric and Power Company | Virginia Regulation | Rider GV

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

9.40%

Approved revenue required

$ 82,000,000

Virginia Electric and Power Company | Virginia Regulation | Subsequent Event | Rider S

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.20%

Approved revenue required

$ 218,000,000

Virginia Electric and Power Company | Virginia Regulation | Subsequent Event | Rider W

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.20%

Approved revenue required

$ 109,000,000

Virginia Electric and Power Company | Virginia Regulation | Subsequent Event | Rider R

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

10.20%

Approved revenue required

$ 66,000,000

Virginia Electric and Power Company | Virginia Regulation | Subsequent Event | Rider GV

Public Utilities, General Disclosures [Line Items]

ROE (percentage)

9.20%

Virginia Electric and Power Company | Federal Energy Regulatory Commission | Settled Litigation | Order Regarding Transmission Rate Design for Allocation of Costs among PJM Interconnect LLC Transmission Customers | Unfavorable Regulatory Action

Public Utilities, General Disclosures [Line Items]

Amount required to pay under settlement agreement (approximately $200 million)

$ 200,000,000

Duration of payment under settlement agreement

10 years

Amount of contingent liability

231,000,000

$ 231,000,000

Virginia Electric and Power Company | Federal Energy Regulatory Commission | Settled Litigation | Order Regarding Transmission Rate Design for Allocation of Costs among PJM Interconnect LLC Transmission Customers | Unfavorable Regulatory Action | PJM transmission rates

Public Utilities, General Disclosures [Line Items]

Regulatory assets-noncurrent

222,000,000

222,000,000

Virginia Electric and Power Company | North Carolina Regulation | Annual Base Fuel Revenues

Public Utilities, General Disclosures [Line Items]

Increase (decrease) in revenue requirement

$ 15,000,000

East Ohio | Ohio Regulation | Pipeline Infrastructure Replacement Program

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

157,000,000

Percentage replacement of pipeline system

25.00%

Period for capital investment

5 years

Estimated cost of project

$ 200,000,000

Annual percentage increase in capital investment

3.00%

Total estimated cost

$ 1,200,000

$ 188,000,000

1,200,000

188,000,000

East Ohio | Ohio Regulation | Automated Meter Reading Program

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

$ 6,000,000

Number of customers with automated meter reading technology | Customer

1.2

East Ohio | Ohio Regulation | Percentage Of Income Payment Plan Rider

Public Utilities, General Disclosures [Line Items]

Refund of over-recovery of accumulated arrearages

19

Recovery of projected deferred program costs

$ 20

East Ohio | Ohio Regulation | UEX Rider

Public Utilities, General Disclosures [Line Items]

Elimination of over-recovered balance of accumulated bad debt expense

$ 12,000,000

Prospective bad debt expense recovered

$ 22,000,000

East Ohio | Ohio Regulation | Demand Side Management Costs [Member]

Public Utilities, General Disclosures [Line Items]

Annual electric power cost rate adjustment, approval amount requested to recover amount

5,000,000

DETI | Federal Energy Regulatory Commission | Preliminary recommendation one | Other operations and maintenance

Public Utilities, General Disclosures [Line Items]

Audit compliance charge recognized in connection with preliminary recommendation

15,000,000

Audit compliance after-tax charge recognized in connection with preliminary recommendation

9,000,000

DETI | Federal Energy Regulatory Commission | Other preliminary recommendation | Other operations and maintenance

Public Utilities, General Disclosures [Line Items]

Audit compliance charge recognized in connection with preliminary recommendation

0

Audit compliance after-tax charge recognized in connection with preliminary recommendation

0

DETI | Federal Energy Regulatory Commission | Atlantic Coast Pipeline | Supply Header Project

Public Utilities, General Disclosures [Line Items]

Annual electric power cost rate adjustment, approval amount requested to recover amount

6,000,000

Annual transportation cost rate adjustment, approval amount requested to recover amount

$ 39,000,000

Hope Gas, Inc. | West Virginia Regulation | PREP

Public Utilities, General Disclosures [Line Items]

Projected capital investment

$ 27,000,000

$ 21,000,000

Amount of cost recovery

4,000,000

Hope Gas, Inc. | West Virginia Regulation | Scenario, Forecast | PREP

Public Utilities, General Disclosures [Line Items]

Projected capital investment

$ 31,000,000

Questar Gas | Utah and Wyoming Regulation

Public Utilities, General Disclosures [Line Items]

Proposed cost increase (decrease) amount

25,000,000

Cove Point | Federal Energy Regulatory Commission

Public Utilities, General Disclosures [Line Items]

Proposed revenue requirement

$ 140,000,000

Number of proposed rates to be effective | Rate

23

Number of proposed rates that were suspended | Rate

5

Cove Point | Federal Energy Regulatory Commission | Operating Revenue

Public Utilities, General Disclosures [Line Items]

Public utilities rate decrease amount

(18,000,000)

Cove Point | Federal Energy Regulatory Commission | Depreciation Expense

Public Utilities, General Disclosures [Line Items]

Public utilities rate decrease amount

$ (3,000,000)

[1]

Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information.

Asset Retirement Obligations (C

Asset Retirement Obligations (Changes to AROs) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, Beginning balance		$ 2,485	[1]	$ 2,103
Obligations incurred during the period		37		204	[2]
Obligations settled during the period		(214)		(171)
Revisions in estimated cash flows		7		245	[3]
Accretion		117		104
AROs, Ending balance	[1]	2,432		2,485
Asset retirement obligations, non current		2,169		2,236
Current Liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, current		263		249
Virginia Electric and Power Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, Beginning balance		1,443		1,247
Obligations incurred during the period		11		9
Obligations settled during the period		(152)		(115)
Revisions in estimated cash flows		(1)		245	[3]
Accretion		64		57
AROs, Ending balance		1,365		1,443
Asset retirement obligation, current		216		181
Asset retirement obligations, non current		1,149		1,262
Dominion Energy Gas Holdings, LLC
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, Beginning balance		156	[4]	149
Obligations incurred during the period		2		6
Obligations settled during the period		(7)		(8)
Accretion		9		9
AROs, Ending balance	[4]	160		156
Dominion Energy Gas Holdings, LLC | Other Deferred Credits And Other Liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, non current		$ 146		$ 147
[1]	Includes $249 million and $263 million reported in other current liabilities at December 31, 2016, and 2017, respectively.
[2]	Primarily reflects AROs assumed in the Dominion Energy Questar Combination. See Note 3 for further information.
[3]	Primarily reflects future ash pond and landfill closure costs at certain utility generation facilities. See Note 22 for further information.
[4]	Includes $147 million and $146 million reported in other deferred credits and other liabilities, with the remainder recorded in other current liabilities, at December 31, 2016 and 2017, respectively.

Asset Retirement Obligations (N

Asset Retirement Obligations (Narrative) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligations [Line Items]
Nuclear decommissioning trust funds	$ 5,093	$ 4,484
Virginia Electric and Power Company
Asset Retirement Obligations [Line Items]
Nuclear decommissioning trust funds	$ 2,399	$ 2,106

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)MWGenerators	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)Generators
Variable Interest Entity [Line Items]
Securities due within one year	$ 3,078	$ 1,709
Long term debt	30,948	30,231
Virginia Electric and Power Company
Variable Interest Entity [Line Items]
Securities due within one year	850	678
Long term debt	10,496	9,852
Dominion Energy Gas Holdings, LLC
Variable Interest Entity [Line Items]
Long term debt	$ 3,570	3,528
Variable Interest Entity, Primary Beneficiary | Partnership Interest | Merchant Solar Projects
Variable Interest Entity [Line Items]
Initial membership interest percentage	67.00%
Variable Interest Entity, Primary Beneficiary | SBL Holdco
Variable Interest Entity [Line Items]
Securities due within one year	$ 30
Long term debt	$ 332
Variable Interest Entity, Primary Beneficiary | Dominion Energy Midstream Partners, LP | Partnership Interest | Limited Partner
Variable Interest Entity [Line Items]
Percentage of limited partner interests in Dominion Midstream Partners, LP	50.60%
Variable Interest Entity, Primary Beneficiary | Dominion Energy Midstream Partners, LP | Partnership Interest | Preferred Partner
Variable Interest Entity [Line Items]
Percentage of limited partner interests in Dominion Midstream Partners, LP	37.50%
Variable Interest Entity, Not Primary Beneficiary | Distribution | Atlantic Coast Pipeline | Pipelines | Jointly Owned Natural Gas Pipeline
Variable Interest Entity [Line Items]
Initial membership interest percentage	48.00%
Variable Interest Entity, Not Primary Beneficiary | Virginia Electric and Power Company | DES
Variable Interest Entity [Line Items]
Shared services purchased	$ 340	346	$ 318
Variable Interest Entity, Not Primary Beneficiary | Dominion Energy Gas Holdings, LLC | DES
Variable Interest Entity [Line Items]
Shared services purchased	$ 126	123	$ 115
Variable Interest Entity (VIE) or Potential VIE, Information Unavailability | Virginia Electric and Power Company
Variable Interest Entity [Line Items]
Long term capacity contract non utility generators (generators) | Generators			5
Number of expired non-utility generators | Generators			2
Number of expired additional non-utility generators | Generators	2
Aggregate generation capacity from long-term power and capacity contracts (MW) | MW	218
Remaining purchase commitments	$ 200
Payment for electric capacity	86	144	$ 200
Payment for electric energy	$ 24	$ 31	$ 83

Short-Term Debt and Credit A122

Short-Term Debt and Credit Agreements (Commercial Paper, Bank Loans and Letters of Credit Outstanding) (Detail) - USD ($)		Dec. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Facility Limit		$ 5,500,000,000	$ 5,500,000,000
Outstanding Commercial Paper	[1]	3,298,000,000	3,155,000,000
Outstanding Letters of Credit		76,000,000	85,000,000
Facility Capacity Available		2,126,000,000	2,260,000,000
Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Facility Limit	[2]	1,500,000,000	1,500,000,000
Outstanding Commercial Paper	[3]	629,000,000	460,000,000
Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit	[4]	5,500,000,000	5,500,000,000
Outstanding Commercial Paper	[5]	542,000,000	65,000,000
Outstanding Letters of Credit			1,000,000
Credit Facility 5 Billion
Line of Credit Facility [Line Items]
Facility Limit	[6]	5,000,000,000	5,000,000,000
Outstanding Commercial Paper	[1],[6]	3,298,000,000	3,155,000,000
Facility Capacity Available	[6]	1,702,000,000	1,845,000,000
Credit Facility 5 Billion | Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit	[4]	5,000,000,000	5,000,000,000
Outstanding Commercial Paper	[4],[5]	542,000,000	65,000,000
Credit Facility 500 Million
Line of Credit Facility [Line Items]
Facility Limit	[6]	500,000,000	500,000,000
Outstanding Letters of Credit	[6]	76,000,000	85,000,000
Facility Capacity Available	[6]	424,000,000	415,000,000
Credit Facility 500 Million | Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Facility Limit	[2]	500,000,000	500,000,000
Credit Facility 500 Million | Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit	[4]	500,000,000	500,000,000
Outstanding Letters of Credit	[4]		1,000,000
Credit Facility 1 Billion | Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Facility Limit	[2]	1,000,000,000	1,000,000,000
Outstanding Commercial Paper	[2],[3]	$ 629,000,000	$ 460,000,000
[1]	The weighted-average interest rates of the outstanding commercial paper supported by Dominion Energy's credit facilities were 1.61% and 1.05% at December 31, 2017 and 2016, respectively.
[2]	A maximum of a combined $1.5 billion of the facilities is available to Dominion Energy Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. Sub-limits for Dominion Energy Gas are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Dominion Energy Gas was an aggregate $500 million. If Dominion Energy Gas has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These credit facilities mature in April 2020 and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.5 billion (or the sub-limit, whichever is less) of letters of credit.
[3]	The weighted-average interest rate of the outstanding commercial paper supported by these credit facilities was 1.57% and 1.00% at December 31, 2017 and 2016, respectively.
[4]	The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion Energy, Dominion Energy Gas and Questar Gas. Sub-limits for Virginia Power are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Virginia Power was an aggregate $1.5 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These facilities mature in April 2020, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.
[5]	The weighted-average interest rates of the outstanding commercial paper supported by these credit facilities were 1.65% and 0.97% at December 31, 2017 and 2016, respectively.
[6]	These credit facilities mature in April 2020, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to a combined $2.0 billion of letters of credit.

Short-Term Debt and Credit A123

Short-Term Debt and Credit Agreements (Commercial Paper, Bank Loans and Letters of Credit Outstanding) (Parenthetical) (Detail) - USD ($)		Dec. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Facility Limit		$ 5,500,000,000	$ 5,500,000,000
Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Facility Limit	[1]	1,500,000,000	1,500,000,000
Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit	[2]	$ 5,500,000,000	$ 5,500,000,000
Weighted-average percentage interest rates	[3]	4.17%
Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Facility Limit		$ 1,500,000,000
Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit		1,500,000,000
Letter of Credit | Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million
Line of Credit Facility [Line Items]
Facility Limit		2,000,000,000
Letter of Credit | Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Facility Limit		$ 2,000,000,000
Commercial Paper | Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million
Line of Credit Facility [Line Items]
Weighted-average percentage interest rates		1.61%	1.05%
Commercial Paper | Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Weighted-average percentage interest rates		1.57%	1.00%
Commercial Paper | Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Virginia Electric and Power Company
Line of Credit Facility [Line Items]
Weighted-average percentage interest rates		1.65%	0.97%
Line of Credit | Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Dominion Energy Gas Holdings, LLC
Line of Credit Facility [Line Items]
Facility Limit		$ 500,000,000
[1]	A maximum of a combined $1.5 billion of the facilities is available to Dominion Energy Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. Sub-limits for Dominion Energy Gas are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Dominion Energy Gas was an aggregate $500 million. If Dominion Energy Gas has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These credit facilities mature in April 2020 and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.5 billion (or the sub-limit, whichever is less) of letters of credit.
[2]	The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion Energy, Dominion Energy Gas and Questar Gas. Sub-limits for Virginia Power are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Virginia Power was an aggregate $1.5 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These facilities mature in April 2020, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.
[3]	Represents weighted-average coupon rates for debt outstanding as of December 31, 2017.

Short-Term Debt and Credit A124

Short-Term Debt and Credit Agreements (Narrative) (Detail)		1 Months Ended	3 Months Ended	12 Months Ended
		Feb. 28, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)CreditFacility	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Facility Limit				$ 5,500,000,000	$ 5,500,000,000
Short-term debt				$ 3,298,000,000	3,155,000,000
Number of joint revolving credit facilities | CreditFacility				2
Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit	[1]			$ 5,500,000,000	5,500,000,000
Short-term debt				542,000,000	$ 65,000,000
Credit facility				100,000,000
Variable rate tax-exempt financings				100,000,000
Virginia Electric and Power Company | Subsequent Event
Debt Instrument [Line Items]
Redemption of credit facility		$ 100,000,000
Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Questar Gas
Debt Instrument [Line Items]
Facility Limit				250,000,000
Joint Revolving Credit Facility 5 Billion and Joint Revolving Credit Facility 500 Million | Virginia Electric and Power Company
Debt Instrument [Line Items]
Facility Limit				1,500,000,000
Credit Facilities, Maturing in December 2018 with 1 year Automatic Renewals through 2023 | SBL Holdco
Debt Instrument [Line Items]
Facility Limit				$ 30,000,000
Automatic renewal period				1 year
Short-term debt				$ 0
Credit Facilities, Maturing in May 2018 with 1 year Automatic Renewals through 2024 | Dominion Solar Projects III, Inc
Debt Instrument [Line Items]
Facility Limit				$ 25,000,000
Automatic renewal period				1 year
Short-term debt				$ 0
Six Billion Joint Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum allowed total debt to total capital ratio				65.00%
Six Billion Joint Revolving Credit Facility [Member] | Scenario, Forecast
Debt Instrument [Line Items]
Facility Limit			$ 6,000,000,000
Duration of credit facilities			5 years
Maximum allowed total debt to total capital ratio			67.50%
Term Loan Credit Agreement [Member]
Debt Instrument [Line Items]
Duration of credit facilities		364 days
Maximum allowed total debt to total capital ratio		67.50%
Guarantee recorded amount		$ 950,000,000
[1]	The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion Energy, Dominion Energy Gas and Questar Gas. Sub-limits for Virginia Power are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Virginia Power was an aggregate $1.5 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These facilities mature in April 2020, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.

Long-Term Debt (Total Long Term

Long-Term Debt (Total Long Term Debt) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total principal		$ 34,293	$ 32,192
Fair value hedge valuation	[1]	(22)	(1)
Securities due within one year	[2],[3]	(3,078)	(1,709)
Unamortized discount and debt issuance costs		245	251
Dominion Energy, Inc. total long-term debt		$ 30,948	30,231
Long Term Debt Due Within One Year [Member]
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[2],[3],[4]	3.44%
Senior Notes | Variable rates, due 2019 and 2020
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	1.99%
Total principal		$ 800
Senior Notes | 1.25% to 6.4%, due 2017 to 2022
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	2.95%
Total principal		$ 5,800	5,750
Senior Notes | 2.85% to 7.0%, due 2024 to 2044
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	4.72%
Total principal		$ 5,049	4,649
Senior Notes | 6.8% and 6.875%, due 2026 and 2027
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	6.81%
Dominion Energy, Inc. total long-term debt	[5]	$ 89	89
Senior Notes | 5.31% to 6.85%, due 2017 and 2018
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	5.72%
Total principal	[6]	$ 120	135
Senior Notes | 2.98% to 7.20%, due 2024 to 2051
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	4.37%
Total principal		$ 600	500
Term Loans | Tax-Exempt Financing, variable rate, due 2041
Debt Instrument [Line Items]
Total principal	[7]		75
Term Loans | Term loan, variable rate, due 2017
Debt Instrument [Line Items]
Total principal	[6]		250
Term Loans | Term Loans, variable rates, due 2023 and 2024 [Member]
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4],[8]	3.74%
Total principal	[8]	$ 638	405
Term Loans | Tax-Exempt Financing, 1.55%, due 2033
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4],[9]	1.55%
Total principal	[9]	$ 27	27
Unsecured Junior Subordinated Notes | : 2.579% to 4.104%, due 2019 to 2021
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	3.08%
Total principal		$ 2,100	1,100
Unsecured Junior Subordinated Notes | Payable to Affiliated Trust, 8.4% due 2031
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	8.40%
Total principal		$ 10	10
Unsecured Junior Subordinated Notes | 5.25% and 5.75%, due 2054 and 2076
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	5.48%
Total principal		$ 1,485	1,485
Unsecured Junior Subordinated Notes | Variable rates, due 2066
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	4.15%
Total principal		$ 422	422
Remarketable Subordinated Notes | Remarketable Subordinated Notes, 1.5% and 2.0%, due 2020 to 2024
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	2.00%
Total principal		$ 1,400	2,400
Dominion Energy Gas Holdings, LLC
Debt Instrument [Line Items]
Total principal		3,600	3,563
Unamortized discount and debt issuance costs		(30)	(35)
Dominion Energy, Inc. total long-term debt		$ 3,570	3,528
Dominion Energy Gas Holdings, LLC | Senior Notes | 2.5% and 2.8%, due 2019 and 2020
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	2.68%
Total principal		$ 1,150	1,150
Dominion Energy Gas Holdings, LLC | Senior Notes | 2.875% to 4.8%, due 2023 to 2044
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4],[10]	3.90%
Total principal	[10]	$ 2,450	2,413
Virginia Electric and Power Company
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	4.17%
Total principal		$ 11,418	10,597
Securities due within one year		(850)	(678)
Unamortized discount and debt issuance costs		(72)	(67)
Dominion Energy, Inc. total long-term debt		$ 10,496	9,852
Virginia Electric and Power Company | Senior Notes | 1.2% to 7.25%, due 2017 to 2022
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	3.92%
Total principal	[11],[12]	$ 1,950	2,554
Virginia Electric and Power Company | Senior Notes | 2.75% to 8.875%, due 2023 to 2047
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	4.53%
Total principal		$ 8,690	7,190
Virginia Electric and Power Company | Term Loans | Variable rates, due 2017 to 2027
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	1.27%
Total principal		$ 100	175
Virginia Electric and Power Company | Tax Exempt Financing [Member] | 1.75% to 5.6%, due 2023 to 2041
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	2.25%
Total principal		$ 678	678
Dominion Energy Midstream Partners, LP
Debt Instrument [Line Items]
Securities due within one year		$ 250
Dominion Energy Midstream Partners, LP | Senior Notes | Unsecured Senior and Medium Term Notes, 5.83% and 6.48%, due 2018
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4],[9]	5.84%
Total principal	[13]	$ 255	255
Dominion Energy Midstream Partners, LP | Senior Notes | Unsecured Senior Note, 4.875%, due 2041
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4],[13]	4.88%
Total principal	[13]	$ 180	180
Dominion Energy Midstream Partners, LP | Term Loans | Term Loan, variable rate, due 2019
Debt Instrument [Line Items]
2017 Weighted- average Coupon (percentage)	[4]	2.74%
Total principal		$ 300	$ 300
[1]	Represents the valuation of certain fair value hedges associated with Dominion Energy's fixed rate debt.
[2]	Excludes $250 million of Dominion Energy Questar Pipeline's senior notes that matured in February 2018 which were repaid using proceeds from the January 2018 issuance, through private placement, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively.
[3]	Includes $20 million of estimated mandatory prepayments due within one year based on estimated cash flows in excess of debt service at SBL Holdco and Dominion Solar Projects III, Inc.
[4]	Represents weighted-average coupon rates for debt outstanding as of December 31, 2017.
[5]	Represents debt assumed by Dominion Energy from the merger of its former CNG subsidiary.
[6]	Represents debt obligations of Dominion Energy Questar or Questar Gas. See Note 3 for more information.
[7]	Represents variable rate Massachusetts Development Finance Agency Solid Waste Disposal Revenue Bonds due in 2041 repaid in August 2017.
[8]	Represents debt associated with SBL Holdco and Dominion Solar Projects III, Inc. The debt is nonrecourse to Dominion Energy and is secured by SBL Holdco's and Dominion Solar Projects III, Inc.'s interest in certain merchant solar facilities.
[9]	Represents debt obligations of a DGI subsidiary.
[10]	Amount includes foreign currency remeasurement adjustments.
[11]	Annual interest rate applies to each of the Series A-1 RSNs and Series A-2 RSNs.
[12]	These financings relate to certain pollution control equipment at Virginia Power's generating facilities. As of December 31, 2017, certain variable rate tax-exempt financings are supported by a $100 million credit facility that terminates in April 2020. In February 2018, Virginia Power provided notice to redeem three series of variable rate tax-exempt financings with an aggregate outstanding principal of $100 million. The financings would otherwise mature in 2024, 2026 and 2027.
[13]	Represents debt obligations of Dominion Energy Questar Pipeline. See Note 3 for more information.

Long-Term Debt (Total Long T126

Long-Term Debt (Total Long Term Debt) (Parenthetical) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Repayment of Debt		$ 1,572	$ 1,610	$ 892
Term Loans
Debt Instrument [Line Items]
Estimated mandatory prepayments due within one year		20
Dominion Energy Gas Holdings, LLC
Debt Instrument [Line Items]
Repayment of Debt			400
Virginia Electric and Power Company
Debt Instrument [Line Items]
Repayment of Debt		$ 681	$ 517	$ 625
Dominion Energy Midstream Partners, LP | Subsequent Event
Debt Instrument [Line Items]
Repayment of Debt	$ 250
2.5% and 2.8%, due 2019 and 2020 | Dominion Energy Gas Holdings, LLC | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		2.50%
2.5% and 2.8%, due 2019 and 2020 | Dominion Energy Gas Holdings, LLC | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		2.80%
2.875% to 4.8%, due 2023 to 2044 | Dominion Energy Gas Holdings, LLC | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		2.875%
2.875% to 4.8%, due 2023 to 2044 | Dominion Energy Gas Holdings, LLC | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		4.80%
1.2% to 7.25%, due 2017 to 2022 | Virginia Electric and Power Company | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		1.20%
1.2% to 7.25%, due 2017 to 2022 | Virginia Electric and Power Company | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		7.25%
2.75% to 8.875%, due 2023 to 2047 | Virginia Electric and Power Company | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		2.75%
2.75% to 8.875%, due 2023 to 2047 | Virginia Electric and Power Company | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		8.875%
1.75% to 5.6%, due 2023 to 2041 | Virginia Electric and Power Company | Tax Exempt Financing [Member] | Minimum
Debt Instrument [Line Items]
Interest rate		1.75%
1.75% to 5.6%, due 2023 to 2041 | Virginia Electric and Power Company | Tax Exempt Financing [Member] | Maximum
Debt Instrument [Line Items]
Interest rate		5.60%
1.25% to 6.4%, due 2017 to 2022 | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		1.25%
1.25% to 6.4%, due 2017 to 2022 | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		6.40%
2.85% to 7.0%, due 2024 to 2044 | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		2.85%
2.85% to 7.0%, due 2024 to 2044 | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		7.00%
: 2.579% to 4.104%, due 2019 to 2021 | Unsecured Junior Subordinated Notes | Minimum
Debt Instrument [Line Items]
Interest rate		2.579%
: 2.579% to 4.104%, due 2019 to 2021 | Unsecured Junior Subordinated Notes | Maximum
Debt Instrument [Line Items]
Interest rate		4.104%
Payable to Affiliated Trust, 8.4% due 2031 | Unsecured Junior Subordinated Notes
Debt Instrument [Line Items]
Interest rate		8.40%
5.25% and 5.75%, due 2054 and 2076 | Unsecured Junior Subordinated Notes | Minimum
Debt Instrument [Line Items]
Interest rate		5.25%
5.25% and 5.75%, due 2054 and 2076 | Unsecured Junior Subordinated Notes | Maximum
Debt Instrument [Line Items]
Interest rate		5.75%
Remarketable Subordinated Notes, 1.5% and 2.0%, due 2020 to 2024 | Remarketable Subordinated Notes | Minimum
Debt Instrument [Line Items]
Interest rate		1.50%
Remarketable Subordinated Notes, 1.5% and 2.0%, due 2020 to 2024 | Remarketable Subordinated Notes | Maximum
Debt Instrument [Line Items]
Interest rate		2.00%
6.8% and 6.875%, due 2026 and 2027 | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		6.80%
6.8% and 6.875%, due 2026 and 2027 | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		6.875%
5.31% to 6.85%, due 2017 and 2018 | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		6.85%
5.31% to 6.85%, due 2017 and 2018 | Term Loans | Minimum
Debt Instrument [Line Items]
Interest rate		5.31%
2.98% to 7.20%, due 2024 to 2051 | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		2.98%
2.98% to 7.20%, due 2024 to 2051 | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		7.20%
Tax-Exempt Financing, 1.55%, due 2033 | Term Loans
Debt Instrument [Line Items]
Interest rate		1.55%
Unsecured Senior and Medium Term Notes, 5.83% and 6.48%, due 2018 | Dominion Energy Midstream Partners, LP | Senior Notes | Minimum
Debt Instrument [Line Items]
Interest rate		5.83%
Unsecured Senior and Medium Term Notes, 5.83% and 6.48%, due 2018 | Dominion Energy Midstream Partners, LP | Senior Notes | Maximum
Debt Instrument [Line Items]
Interest rate		6.48%
Unsecured Senior Note, 4.875%, due 2041 | Dominion Energy Midstream Partners, LP | Senior Notes
Debt Instrument [Line Items]
Interest rate		4.875%
3.53% Due 2028 | Dominion Energy Midstream Partners, LP | Private Placement | Subsequent Event
Debt Instrument [Line Items]
Repayment of Debt	$ 100
Interest rate	3.53%
3.91% Due 2038 | Dominion Energy Midstream Partners, LP | Private Placement | Subsequent Event
Debt Instrument [Line Items]
Repayment of Debt	$ 150
Interest rate	3.91%
Line of Credit | Virginia Electric and Power Company
Debt Instrument [Line Items]
Credit facility, to support letters of credit		$ 100

Long-Term Debt (Based on Stated

Long-Term Debt (Based on Stated Maturity Dates Rather than Early Redemption Dates that Could be Elected by Instrument Holders) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
2,018	$ 3,311
2,019	4,286
2,020	2,035
2,021	2,185
2,022	1,534
Thereafter	20,942
Total	$ 34,293
Weighted- average Coupon, 2018	3.62%
Weighted- average Coupon, 2019	2.89%
Weighted- average Coupon, 2020	2.58%
Weighted- average Coupon, 2021	3.12%
Weighted- average Coupon, 2022	2.97%
Weighted- average Coupon, Thereafter	4.38%
Unsecured Senior Notes
Debt Instrument [Line Items]
2,018	$ 3,275	[1]
2,019	3,400	[1]
2,020	1,000	[1]
2,021	900	[1]
2,022	1,500	[1]
Thereafter	17,058	[1]
Total	27,133	[1]
Tax-Exempt Financings
Debt Instrument [Line Items]
Thereafter	805
Total	805
Term Loans
Debt Instrument [Line Items]
2,018	36	[2]
2,019	336	[2]
2,020	35	[2]
2,021	35	[2]
2,022	34	[2]
Thereafter	462	[2]
Total	938	[2]
Unsecured Junior Subordinated Notes Payable to Affiliated Trusts
Debt Instrument [Line Items]
Thereafter	10
Total	10
Unsecured Junior Subordinated Notes
Debt Instrument [Line Items]
2,019	550
2,020	1,000
2,021	550
Total	2,100
Unsecured Junior Subordinated Notes
Debt Instrument [Line Items]
Thereafter	1,907
Total	1,907
Remarketable Subordinated Notes
Debt Instrument [Line Items]
2,021	700
Thereafter	700
Total	1,400
Dominion Energy Gas Holdings, LLC
Debt Instrument [Line Items]
2,019	450
2,020	700
Thereafter	2,450
Total	$ 3,600
Weighted- average Coupon, 2019	2.50%
Weighted- average Coupon, 2020	2.80%
Weighted- average Coupon, Thereafter	3.90%
Virginia Electric and Power Company
Debt Instrument [Line Items]
2,018	$ 850
2,019	350
2,022	750
Thereafter	9,468
Total	$ 11,418
Weighted- average Coupon, 2018	4.17%
Weighted- average Coupon, 2019	5.00%
Weighted- average Coupon, 2022	3.15%
Weighted- average Coupon, Thereafter	4.33%
Virginia Electric and Power Company | Unsecured Senior Notes
Debt Instrument [Line Items]
2,018	$ 850
2,019	350
2,022	750
Thereafter	8,690
Total	10,640
Virginia Electric and Power Company | Tax-Exempt Financings
Debt Instrument [Line Items]
Thereafter	778
Total	$ 778
[1]	In February 2018, $250 million of Dominion Energy Questar Pipeline's senior notes were repaid using proceeds from the January 2018 issuance, through private placements, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively. As a result, at December 31, 2017, $250 million was included in long-term debt in the Consolidated Balance Sheets.
[2]	Excludes mandatory prepayments associated with SBL Holdco and Dominion Solar Projects III, Inc. based on cash flows in excess of debt service. At December 31, 2017, $20 million of estimated mandatory prepayments due within one year were included in securities due within one year in Dominion Energy's Consolidated Balance Sheets.

Long-Term Debt (Based on Sta128

Long-Term Debt (Based on Stated Maturity Dates Rather than Early Redemption Dates that Could be Elected by Instrument Holders) (Parenthetical) (Detail) - USD ($) $ in Millions		1 Months Ended	12 Months Ended
		Feb. 28, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Repayment of Debt			$ 1,572	$ 1,610	$ 892
Securities due within one year	[1],[2]		(3,078)	$ (1,709)
Term Loans
Debt Instrument [Line Items]
Estimated mandatory prepayments due within one year			20
Dominion Energy Midstream Partners, LP
Debt Instrument [Line Items]
Securities due within one year			$ 250
Dominion Energy Midstream Partners, LP | Subsequent Event
Debt Instrument [Line Items]
Repayment of Debt		$ 250
3.53% Due 2028 | Dominion Energy Midstream Partners, LP | Private Placement | Subsequent Event
Debt Instrument [Line Items]
Repayment of Debt		$ 100
Interest rate		3.53%
3.91% Due 2038 | Dominion Energy Midstream Partners, LP | Private Placement | Subsequent Event
Debt Instrument [Line Items]
Repayment of Debt		$ 150
Interest rate		3.91%
[1]	Excludes $250 million of Dominion Energy Questar Pipeline's senior notes that matured in February 2018 which were repaid using proceeds from the January 2018 issuance, through private placement, of $100 million of 3.53% senior notes and $150 million of 3.91% senior notes that mature in 2028 and 2038, respectively.
[2]	Includes $20 million of estimated mandatory prepayments due within one year based on estimated cash flows in excess of debt service at SBL Holdco and Dominion Solar Projects III, Inc.

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Detail) - USD ($)

Oct. 01, 2024

Aug. 15, 2016

Aug. 31, 2019

Jul. 31, 2017

Jul. 31, 2016

Apr. 30, 2016

Oct. 31, 2014

Sep. 30, 2011

Sep. 30, 2006

Jun. 30, 2006

Dec. 31, 2017

May 31, 2017

Aug. 31, 2016

Jun. 29, 2016

May 31, 2016

Mar. 31, 2016

Dec. 31, 2015

Jul. 31, 2014

Jul. 31, 2013

Debt Instrument [Line Items]

Period of deferral

10 years

Period for consideration of proceeds (days)

180 days

365 days

Interest in RSN issued by Dominion (percentage)

5.00%

Capital Unit, Class A

Debt Instrument [Line Items]

Principal amount of notes

$ 1,400,000,000

Payment percentage rate on Equity Units

6.75%

6.375%

6.125%

Purchase price to be paid under stock purchase contracts (in dollars per unit)

$ 50

Issuance of common stock (in shares)

28,000,000

[1]

12,500,000

Capital Unit, Class B

Debt Instrument [Line Items]

Payment percentage rate on Equity Units

6.00%

Common Stock

Debt Instrument [Line Items]

Purchase price to be paid under stock purchase contracts (in dollars per unit)

$ 50

Shares reserved and available for issuance

23,100,000

Remarketable Subordinated Notes | Capital Unit, Class A

Debt Instrument [Line Items]

Interest rate (percentage)

2.00%

[1],[2]

1.50%

1.07%

Principal amount of notes

$ 1,400,000,000

[1]

$ 1,000,000,000

$ 550,000,000

$ 1,000,000,000

Issuance of common stock (in shares)

12,500,000

8,500,000

8,500,000

Remarketable Subordinated Notes | Capital Unit, Class B

Debt Instrument [Line Items]

Interest rate (percentage)

1.18%

Principal amount of notes

$ 550,000,000

Remarketable Subordinated Notes, 2016 Series A-1, due August 15, 2021

Debt Instrument [Line Items]

Interest in RSN issued by Dominion (percentage)

2.50%

Remarketable Subordinated Notes, 2016 Series A-1, due August 15, 2021 | Capital Unit, Class A

Debt Instrument [Line Items]

Principal amount of notes

700,000,000

Remarketable Subordinated Notes, 2016 Series A-2, due August 15, 2024

Debt Instrument [Line Items]

Interest in RSN issued by Dominion (percentage)

2.50%

Remarketable Subordinated Notes, 2016 Series A-2, due August 15, 2024 | Capital Unit, Class A

Debt Instrument [Line Items]

Principal amount of notes

$ 700,000,000

Scenario, Forecast | Maximum

Debt Instrument [Line Items]

Shares to be issued under purchase contracts

18,800,000

Scenario, Forecast | Minimum

Debt Instrument [Line Items]

Shares to be issued under purchase contracts

15,000,000

Unsecured Junior Subordinated Notes | June 2006 and September 2006 hybrids | Maximum

Debt Instrument [Line Items]

Amount purchased and cancelled

$ 200,000,000

Unsecured Junior Subordinated Notes | July 2016 Hybrids

Debt Instrument [Line Items]

Interest rate (percentage)

5.25%

Principal amount of notes

$ 800,000,000

Unsecured Junior Subordinated Notes | Series A Junior Subordinated Notes

Debt Instrument [Line Items]

Interest rate (percentage)

2.579%

4.104%

Unsecured Junior Subordinated Notes | Series B Junior Subordinated Notes

Debt Instrument [Line Items]

Interest rate (percentage)

2.962%

October 2014 Hybrids [Member] | Unsecured Junior Subordinated Notes

Debt Instrument [Line Items]

Interest rate (percentage)

5.75%

Principal amount of notes

$ 685,000,000

October 2014 Hybrids [Member] | LIBOR [Member] | Unsecured Junior Subordinated Notes | Scenario, Forecast

Debt Instrument [Line Items]

Spread on variable percentage rate

3.057%

June 2006 hybrids

Debt Instrument [Line Items]

Junior subordinated notes

$ 300,000,000

Interest rate (percentage)

7.50%

Aggregate redemption price paid

$ 38,000,000

$ 14,000,000

June 2006 hybrids | Unsecured Junior Subordinated Notes

Debt Instrument [Line Items]

Amount purchased and cancelled

125,000,000

June 2006 hybrids | LIBOR [Member]

Debt Instrument [Line Items]

Spread on variable percentage rate

2.825%

September 2006 hybrids

Debt Instrument [Line Items]

Junior subordinated notes

$ 500,000,000

Aggregate redemption price paid

$ 4,000,000

$ 3,000,000

September 2006 hybrids | Unsecured Junior Subordinated Notes

Debt Instrument [Line Items]

Amount purchased and cancelled

$ 74,000,000

September 2006 hybrids | LIBOR [Member]

Debt Instrument [Line Items]

Spread on variable percentage rate

2.30%

[1]

The maturity dates of the $700 million Series A-1 RSNs and $700 million Series A-2 RSNs are August 15, 2021 and August 15, 2024, respectively.

[2]

Annual interest rate applies to each of the Series A-1 RSNs and Series A-2 RSNs.

Long-Term Debt Long Term Debt (

Long-Term Debt Long Term Debt (Schedule of Equity Units) (Detail) - USD ($) shares in Millions

Aug. 15, 2016

Jul. 31, 2017

Jul. 31, 2016

Apr. 30, 2016

Dec. 31, 2017

May 31, 2017

Dec. 31, 2016

Aug. 31, 2016

Mar. 31, 2016

Jul. 31, 2014

Capital Unit [Line Items]

Stock Purchase Contract Liability

$ 111,000,000

$ 212,000,000

Capital Unit, Class A

Capital Unit [Line Items]

Units Issued

28

[1]

12.5

Total Net Proceeds

[1]

$ 1,374,800,000

Total Long-term Debt

$ 1,400,000,000

Stock Purchase Contract Annual Rate (Percentage)

[1]

4.75%

Stock Purchase Contract Liability

[1],[2]

$ 190,600,000

Stock Purchase Settlement Date

[1]

Aug. 15, 2019

Capital Unit, Class A | Remarketable Subordinated Notes

Capital Unit [Line Items]

Units Issued

12.5

8.5

8.5

Total Long-term Debt

$ 1,400,000,000

[1]

$ 1,000,000,000

$ 550,000,000

$ 1,000,000,000

RSN Annual Interest Rate

2.00%

[1],[3]

1.50%

1.07%

[1]

The maturity dates of the $700 million Series A-1 RSNs and $700 million Series A-2 RSNs are August 15, 2021 and August 15, 2024, respectively.

[2]

Payments of $101 million and $94 million were made in 2017 and 2016, respectively, including payments for the remarketed 2013 Series A and B notes and the remarketed 2014 Series A notes. The stock purchase contract liability was $111 million and $212 million at December 31, 2017 and 2016, respectively.

[3]

Annual interest rate applies to each of the Series A-1 RSNs and Series A-2 RSNs.

Long-Term Debt Long Term Deb131

Long-Term Debt Long Term Debt (Schedule of Equity Units) (Parenthetical) (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Aug. 31, 2016	Aug. 15, 2016
Capital Unit [Line Items]
Stock Purchase Contract Liability		$ 111,000,000	$ 212,000,000
Total payments		$ 101,000,000	$ 94,000,000
Capital Unit, Class A
Capital Unit [Line Items]
Stock Purchase Contract Liability	[1],[2]				$ 190,600,000
Total Long-term Debt				$ 1,400,000,000
Capital Unit, Class A | Remarketable Subordinated Notes, 2016 Series A-1, due August 15, 2021
Capital Unit [Line Items]
Total Long-term Debt					700,000,000
Capital Unit, Class A | Remarketable Subordinated Notes, 2016 Series A-2, due August 15, 2024
Capital Unit [Line Items]
Total Long-term Debt					$ 700,000,000
[1]	Payments of $101 million and $94 million were made in 2017 and 2016, respectively, including payments for the remarketed 2013 Series A and B notes and the remarketed 2014 Series A notes. The stock purchase contract liability was $111 million and $212 million at December 31, 2017 and 2016, respectively.
[2]	The maturity dates of the $700 million Series A-1 RSNs and $700 million Series A-2 RSNs are August 15, 2021 and August 15, 2024, respectively.

Preferred Stock (Narrative) (De

Preferred Stock (Narrative) (Detail) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Preferred stock shares authorized	20,000,000	20,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Virginia Electric and Power Company
Class of Stock [Line Items]
Preferred stock shares authorized	10,000,000	10,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Liquidation preference (in dollars per share)	$ 100

Equity (Narrative) (Detail)

Equity (Narrative) (Detail)

Aug. 15, 2016shares

[1]

Jan. 31, 2018USD ($)shares

Jul. 31, 2017USD ($)shares

Jun. 30, 2017USD ($)Agreement

Jul. 31, 2016shares

Apr. 30, 2016USD ($)shares

Feb. 28, 2015USD ($)

Dec. 31, 2018Performance_Factorshares

Dec. 31, 2017USD ($)shares

Dec. 31, 2016USD ($)Performance_Factorshares

Dec. 31, 2015USD ($)shares

Sep. 30, 2015USD ($)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock

$ 1,302,000,000

$ 2,152,000,000

$ 786,000,000

Common stock, shares outstanding | shares

645,000,000

628,000,000

Issuance of common stock (in shares)

$ 1,302,000,000

$ 2,152,000,000

786,000,000

Net proceeds from issuance of Dominion Midstream common units

$ 18,000,000

482,000,000

Net proceeds from issuance of Dominion Midstream convertible preferred units

490,000,000

Conversion basis

1

Compensation cost related to stock-based compensation

$ 45,000,000

33,000,000

39,000,000

Tax benefit from stock awards and stock options exercised

$ 16,000,000

$ 11,000,000

14,000,000

Vesting period

3 years

Cash Based Performance Grant | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Cash-based performance grants minimum percentage

0.00%

Cash-based performance grants maximum percentage

200.00%

February 2015 Cash Based Performance Grant | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of performance metrics achieved | Performance_Factor

2

Expected award under grant

$ 10,000,000

February 2016 Cash Based Performance Grant | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of performance metrics achieved | Performance_Factor

2

Subsequent Event | February 2016 Cash Based Performance Grant | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expected award under grant

$ 12,000,000

Scenario, Forecast | February 2017 Cash Based Performance Grant [Member] | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of performance metrics achieved | Performance_Factor

2

Dominion Direct Employee Stock Awards Employee Savings Plans Director Stock Compensation Plans and Contingent Convertible Senior Notes

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares reserved and available for issuance | shares

67,000,000

Stock Based Awards

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Shares were available for future grants | shares

23,000,000

Restricted Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Unrecognized compensation cost related to nonvested awards

$ 42,000,000

Fair value of restricted stock awards that vested

$ 21,000,000

$ 21,000,000

$ 37,000,000

Virginia Electric and Power Company

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock (in shares | shares

0

0

0

Common stock, shares outstanding | shares

274,723

274,723

Repurchase of common stock, shares | shares

0

0

Virginia Electric and Power Company | Scenario, Forecast

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Repurchase of common stock, shares | shares

0

Dominion Midstream Partners, LP | Limited Partner

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Net proceeds from issuance of Dominion Midstream common units

$ 18,000,000

$ 482,000,000

Dominion Midstream Partners, LP | Limited Partner | Convertible Preferred Units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Net proceeds from issuance of Dominion Midstream convertible preferred units

$ 490,000,000

Dominion Midstream Partners, LP | Dominion Midstream Limited Partner Common Unit Purchase Program | Limited Partner

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Authorized purchase amount

$ 50,000,000

Stock repurchase program expiration date

Sep. 30, 2016

Number of common units purchased | shares

658,000

887,000

Value of common units purchased

$ 17,000,000

$ 25,000,000

Two-year grant | February 2017 Cash Based Performance Grant [Member] | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Targeted amount of the grant

$ 15,000,000

Liability accrued for award

7,000,000

Three-year grant | February 2017 Cash Based Performance Grant [Member] | Officer

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Targeted amount of the grant

15,000,000

Liability accrued for award

5,000,000

Capital Unit, Class A

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock

$ 1,000,000,000

Issuance of common stock (in shares | shares

28,000,000

12,500,000

Capital Unit, Class A | Remarketable Subordinated Notes

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock

$ 1,100,000,000

Issuance of common stock (in shares | shares

12,500,000

8,500,000

8,500,000

Maximum | Stock Based Awards

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Maximum term of stock based awards

8 years

Weighted Average | Restricted Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Expected weighted-average period recognized for the unrecognized compensation cost

2 years

Various Programs

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock

$ 1,300,000,000

Issuance of common stock (in shares | shares

17,000,000

Common stock, shares outstanding | shares

645,000,000

Employee Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Cash proceeds received from issuance of shares through Dominion Direct and employee savings plans

$ 302,000,000

Number of shares issued through Dominion Direct and employee savings plans | shares

3,800,000

Underwritten Public Offering

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock

$ 756,000,000

Issuance of common stock (in shares | shares

10,200,000

Shelf Registration for Sale of Common Stock through At-the-market Program

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Issuance of common stock

$ 495,000,000

Issuance of common stock (in shares | shares

6,600,000

Number of sales agency agreements | Agreement

3

Issuance of common stock (in shares)

$ 0

Fees and commissions paid

$ 5,000,000

Shelf Registration for Sale of Common Stock through At-the-market Program | Maximum

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Sale of stock authorized amount

$ 500,000,000

[1]

The maturity dates of the $700 million Series A-1 RSNs and $700 million Series A-2 RSNs are August 15, 2021 and August 15, 2024, respectively.

Equity (Accumulated Other Compr

Equity (Accumulated Other Comprehensive Income (Loss)) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI, including noncontrolling interest	$ (658)	$ (799)
Less other comprehensive income attributable to noncontrolling interest	1
Total AOCI	(659)	(799)
Deferred Gains and Losses on Derivatives-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(301)	(280)
Amount of tax	188	173
Unrealized Gains and Losses on Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	747	569
Amount of tax	(419)	(318)
Unrecognized Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(1,101)	(1,082)
Amount of tax	692	691
Other Comprehensive Loss From Equity Method Investee
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(3)	(6)
Amount of tax	2	4
Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(98)	(123)
Dominion Energy Gas Holdings, LLC | Deferred Gains and Losses on Derivatives-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(23)	(24)
Amount of tax	15	15
Dominion Energy Gas Holdings, LLC | Unrecognized Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(75)	(99)
Amount of tax	59	68
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	62	46
Virginia Electric and Power Company | Deferred Gains and Losses on Derivatives-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	(12)	(8)
Amount of tax	8	5
Virginia Electric and Power Company | Unrealized Gains and Losses on Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total AOCI	74	54
Amount of tax	$ (47)	$ 35

Equity (Schedule of Changes in

Equity (Schedule of Changes in AOCI by Component Net of Tax) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ 14,605
Net current period other comprehensive income (loss)		141	$ (325)	$ (58)
Ending balance		17,142	14,605
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		11,865
Net current period other comprehensive income (loss)		16	6	(10)
Ending balance		12,224	11,865
Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net current period other comprehensive income (loss)		25	(24)	(13)
Deferred Gains and Losses on Derivatives-Hedging Activities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(280)	(176)
Other comprehensive income before reclassifications: gains (losses)		8	55
Amounts reclassified from AOCI: (gains) losses	[1]	(29)	(159)
Net current period other comprehensive income (loss)		(21)	(104)
Less other comprehensive income attributable to noncontrolling interest		1
Ending balance		(302)	(280)	(176)
Deferred Gains and Losses on Derivatives-Hedging Activities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(8)	(7)
Other comprehensive income before reclassifications: gains (losses)		(5)	(2)
Amounts reclassified from AOCI: (gains) losses	[1]	1	1
Net current period other comprehensive income (loss)		(4)	(1)
Ending balance		(12)	(8)	(7)
Deferred Gains and Losses on Derivatives-Hedging Activities | Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(24)	(17)
Other comprehensive income before reclassifications: gains (losses)		5	(16)
Amounts reclassified from AOCI: (gains) losses	[1]	(4)	9
Net current period other comprehensive income (loss)		1	(7)
Ending balance		(23)	(24)	(17)
Unrealized Gains and Losses on Investment Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		569	504
Other comprehensive income before reclassifications: gains (losses)		215	93
Amounts reclassified from AOCI: (gains) losses	[1]	(37)	(28)
Net current period other comprehensive income (loss)		178	65
Ending balance		747	569	504
Unrealized Gains and Losses on Investment Securities | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		54	47
Other comprehensive income before reclassifications: gains (losses)		24	11
Amounts reclassified from AOCI: (gains) losses	[1]	(4)	(4)
Net current period other comprehensive income (loss)		20	7
Ending balance		74	54	47
Unrecognized Pension and Other Postretirement Benefit Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,082)	(797)
Other comprehensive income before reclassifications: gains (losses)		(69)	(319)
Amounts reclassified from AOCI: (gains) losses	[1]	50	34
Net current period other comprehensive income (loss)		(19)	(285)
Ending balance		(1,101)	(1,082)	(797)
Unrecognized Pension and Other Postretirement Benefit Costs | Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(99)	(82)
Other comprehensive income before reclassifications: gains (losses)		20	(20)
Amounts reclassified from AOCI: (gains) losses	[1]	4	3
Net current period other comprehensive income (loss)		24	(17)
Ending balance		(75)	(99)	(82)
Other Comprehensive Loss From Equity Method Investee
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(6)	(5)
Other comprehensive income before reclassifications: gains (losses)		3	(1)
Net current period other comprehensive income (loss)		3	(1)
Ending balance		(3)	(6)	(5)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(799)	(474)
Other comprehensive income before reclassifications: gains (losses)		157	(172)
Amounts reclassified from AOCI: (gains) losses	[1]	(16)	(153)
Net current period other comprehensive income (loss)		140	(325)	(58)
Less other comprehensive income attributable to noncontrolling interest		1
Ending balance		(659)	(799)	(474)
Accumulated Other Comprehensive Income (Loss) | Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		46	40
Other comprehensive income before reclassifications: gains (losses)		19	9
Amounts reclassified from AOCI: (gains) losses	[1]	(3)	(3)
Net current period other comprehensive income (loss)		16	6	(10)
Ending balance		62	46	40
Accumulated Other Comprehensive Income (Loss) | Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(123)	(99)
Other comprehensive income before reclassifications: gains (losses)		25	(36)
Amounts reclassified from AOCI: (gains) losses	[1]	0	12
Net current period other comprehensive income (loss)		25	(24)	(13)
Ending balance		$ (98)	$ (123)	$ (99)
[1]	See table below for details about these reclassifications.

Equity (Schedule of Reclassific

Equity (Schedule of Reclassifications out of AOCI by Component Net of Tax) (Detail) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenue		$ 3,210	$ 3,179	$ 2,813	$ 3,384	$ 3,086	$ 3,132	$ 2,598	$ 2,921	$ 12,586	[1]	$ 11,737	[1]	$ 11,683	[1]
Other income	[1]									358		429		312
Purchased gas										(701)		(459)		(551)
Electric fuel and other energy-related purchases										(2,301)		(2,333)		(2,725)
Interest and related charges										(1,205)		(1,010)		(904)
Impairment										(23)		(23)		(31)
Income from operations before income tax expense										3,090		2,867		2,828
Income tax expense										30		(655)		(905)
Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenue		501	401	422	490	457	382	368	431	1,814	[2]	1,638	[2]	1,716	[2]
Other income										104		87		63
Purchased gas	[2]									(132)		(109)		(133)
Interest and related charges	[2]									(97)		(94)		(73)
Income from operations before income tax expense										666		607		740
Income tax expense										(51)		(215)		(283)
Virginia Electric and Power Company
Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenue		$ 1,824	$ 2,154	$ 1,747	$ 1,831	$ 1,711	$ 2,211	$ 1,776	$ 1,890	7,556		7,588		7,622
Other income										76		56		68
Electric fuel and other energy-related purchases	[3]									(1,909)		(1,973)		(2,320)
Interest and related charges	[3]									(494)		(461)		(443)
Impairment										(2)		(3)		(4)
Income from operations before income tax expense										2,314		1,945		1,746
Income tax expense										(774)		(727)		$ (659)
Deferred (gains) and losses on derivatives-hedging activities: | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income from operations before income tax expense										(47)		(259)
Income tax expense										18		100
Income from continuing operations including noncontrolling interests										(29)		(159)
Deferred (gains) and losses on derivatives-hedging activities: | Commodity | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenue										(81)		(330)
Purchased gas										2		13
Electric fuel and other energy-related purchases												10
Deferred (gains) and losses on derivatives-hedging activities: | Interest rate | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges										52		31
Deferred (gains) and losses on derivatives-hedging activities: | Foreign currency | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income										(20)		17
Deferred (gains) and losses on derivatives-hedging activities: | Dominion Energy Gas Holdings, LLC | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income from operations before income tax expense										(7)		15
Income tax expense										3		(6)
Income from continuing operations including noncontrolling interests										(4)		9
Deferred (gains) and losses on derivatives-hedging activities: | Dominion Energy Gas Holdings, LLC | Commodity | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Operating Revenue										8		(4)
Deferred (gains) and losses on derivatives-hedging activities: | Dominion Energy Gas Holdings, LLC | Interest rate | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges										5		2
Deferred (gains) and losses on derivatives-hedging activities: | Dominion Energy Gas Holdings, LLC | Foreign currency | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income										(20)		17
Deferred (gains) and losses on derivatives-hedging activities: | Virginia Electric and Power Company | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income from operations before income tax expense										1		1
Income from continuing operations including noncontrolling interests										1		1
Deferred (gains) and losses on derivatives-hedging activities: | Virginia Electric and Power Company | Interest rate | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest and related charges										1		1
Unrealized (gains) and losses on investment securities: | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Realized (gain) loss on sale of securities										(81)		(66)
Impairment										23		23
Income from operations before income tax expense										(58)		(43)
Income tax expense										21		15
Income from continuing operations including noncontrolling interests										(37)		(28)
Unrealized (gains) and losses on investment securities: | Virginia Electric and Power Company | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Realized (gain) loss on sale of securities										(9)		(9)
Impairment										2		3
Income from operations before income tax expense										(7)		(6)
Income tax expense										3		2
Income from continuing operations including noncontrolling interests										(4)		(4)
Unrecognized pension and other postretirement benefit costs:
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrecognized pension and other postretirement benefit costs, before tax										82		56
Unrecognized pension and other postretirement benefit costs, income tax expense										(32)		(22)
Unrecognized pension and other postretirement benefit costs, net of tax										50		34
Unrecognized pension and other postretirement benefit costs: | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income										(21)		(15)
Other income										103		71
Unrecognized pension and other postretirement benefit costs: | Dominion Energy Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrecognized pension and other postretirement benefit costs, before tax										6		5
Unrecognized pension and other postretirement benefit costs, income tax expense										(2)		(2)
Unrecognized pension and other postretirement benefit costs, net of tax										4		3
Unrecognized pension and other postretirement benefit costs: | Dominion Energy Gas Holdings, LLC | Amounts Reclassified From AOCI
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income										$ 6		$ 5
[1]	See Note 9 for amounts attributable to related parties.
[2]	See Note 24 for amounts attributable to related parties.
[3]	See Note 24 for amounts attributable to affiliates.

Equity (Summary of Restricted S

Equity (Summary of Restricted Stock and Goal-Based Stock Activity) (Detail) - Restricted Stock - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested beginning (in shares)	886	855	1,065
Granted (in shares)	454	372	302
Vested (in shares)	(287)	(301)	(510)
Cancelled and forfeited (in shares)	(10)	(40)	(2)
Nonvested ending (in shares)	1,043	886	855
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Nonvested beginning, Weighted Average Grant Date Fair Value (in dollars per share)	$ 71.40	$ 66.16	$ 56.74
Granted, Weighted Average Grant Date Fair Value (in dollars per share)	74.24	71.67	73.26
Vested, Weighted Average Grant Date Fair Value (in dollars per share)	68.90	56.83	50.71
Cancelled and forfeited, Weighted Average Grant Date Fair Value (in dollars per share)	72.37	71.75	62.62
Nonvested ending, Weighted Average Grant Date Fair Value (in dollars per share)	$ 73.32	$ 71.40	$ 66.16

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Detail) - USD ($)	Sep. 30, 2017	Jun. 30, 2017	Jan. 31, 2017	Dec. 31, 2017	Mar. 31, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on plan assets								$ 1,600,000,000	$ 534,000,000
Expected return on pension and other postretirement plan assets								767,000,000	691,000,000
Net actuarial loss										$ (25,000,000)
Accumulated benefit obligation				$ 8,200,000,000				8,200,000,000	7,300,000,000
Contributions to qualified defined benefit pension plans								0
Contributions to qualified defined benefit pension plans in 2018				$ 0				0
Estimated reduction in net cumulative required contributions								$ 200,000,000
Cumulative required contribution period (years)								10 years
Expected contribution to voluntary employees beneficiary association								$ 12,000,000	12,000,000
Amounts recognized in employer matching contributions								$ 45,000,000	44,000,000	43,000,000
Special Termination Benefits | Organizational Design Initiative
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Organizational design initiative									65,000,000
Organizational design initiative, after tax									40,000,000
Common and Preferred Stocks
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages				28.00%				28.00%
Government Securities
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages				18.00%				18.00%
Fixed Income
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages				35.00%				35.00%
Real Estate Funds
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages				3.00%				3.00%
Other Alternative Investments
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, actual plan asset allocation percentages				16.00%				16.00%
Scenario, Forecast
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected contribution to voluntary employees beneficiary association							$ 12,000,000
Pension or other postretirement plan assets to be returned							0
Dominion Energy Questar Corporation | Capital Contribution to Dominion Energy Questar to Fund Pension Contributions
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution to qualified pension plan								$ 75,000,000
Medical Coverage for Local retirees
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Decrease in accumulated postretirement benefit obligation					$ (73,000,000)	$ 37,000,000
Discount rate percentage					4.30%	3.71%
Charge recorded from plan amendment and remeasurement					$ 7,000,000	$ (9,000,000)
Charge recorded from plan amendment and remeasurement, after tax					4,000,000
Pension Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on plan assets								1,327,000,000	426,000,000
Expected return on pension and other postretirement plan assets								639,000,000	573,000,000	$ 531,000,000
Net actuarial loss				$ 193,000,000				193,000,000
Actuarial (gains) losses during the year								830,000,000	$ 784,000,000
Decrease in accumulated postretirement benefit obligation				(75,000,000)
Discount rate percentage	4.05%	4.05%	4.51%						4.46%	4.40%
Contributions to qualified defined benefit pension plans								118,000,000	$ 15,000,000
Net periodic benefit cost								7,000,000	(25,000,000)	$ 44,000,000
Other Postretirement Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on plan assets								236,000,000	108,000,000
Expected return on pension and other postretirement plan assets								128,000,000	118,000,000	$ 117,000,000
Net actuarial loss				11,000,000				11,000,000
Actuarial (gains) losses during the year								$ 119,000,000	166,000,000
Decrease in accumulated postretirement benefit obligation				$ 2,000,000
Discount rate percentage										4.40%
Discount rate percentage				3.76%				3.76%
Contributions to qualified defined benefit pension plans								$ 13,000,000	12,000,000
Net periodic benefit cost								(80,000,000)	$ (49,000,000)	$ (31,000,000)
Collective Bargaining Agreement
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Period for experience study of employee demographics									5 years
Increase in net periodic benefit costs for 2017									$ 42,000,000
Collective Bargaining Agreement | Pension Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gains) losses during the year									290,000,000
Collective Bargaining Agreement | Other Postretirement Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gains) losses during the year									38,000,000
Dominion Energy Gas Holdings, LLC
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on plan assets								335,000,000	130,000,000
Expected return on pension and other postretirement plan assets								165,000,000	157,000,000
Net actuarial loss										(3,000,000)
Accumulated benefit obligation				$ 724,000,000				724,000,000	640,000,000
Contributions to qualified defined benefit pension plans								0
Contributions to qualified defined benefit pension plans in 2018				0				0
Contribution to qualified pension plan								15,000,000	150,000,000	692,000,000
Amounts recognized in employer matching contributions								7,000,000	7,000,000	7,000,000
Dominion Energy Gas Holdings, LLC | Special Termination Benefits | Organizational Design Initiative
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Organizational design initiative									8,000,000
Organizational design initiative, after tax									5,000,000
Dominion Energy Gas Holdings, LLC | Other operations and maintenance | Dominion Retiree Health And Welfare Plan | Multiemployer Plans, Postretirement Benefit
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost								(5,000,000)	(4,000,000)	(5,000,000)
Dominion Energy Gas Holdings, LLC | Scenario, Forecast
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension or other postretirement plan assets to be returned							$ 0
Dominion Energy Gas Holdings, LLC | Medical Coverage for Local retirees
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Decrease in accumulated postretirement benefit obligation					(61,000,000)
Charge recorded from plan amendment and remeasurement					6,000,000
Charge recorded from plan amendment and remeasurement, after tax					$ 4,000,000
Dominion Energy Gas Holdings, LLC | Pension Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on plan assets								294,000,000	107,000,000
Expected return on pension and other postretirement plan assets								141,000,000	134,000,000	$ 126,000,000
Net actuarial loss				$ 19,000,000				19,000,000
Actuarial (gains) losses during the year								$ 78,000,000	$ 64,000,000
Discount rate percentage								4.50%	4.99%	4.40%
Discount rate percentage				3.81%				3.81%	4.50%
Net periodic benefit cost								$ (80,000,000)	$ (78,000,000)	$ (63,000,000)
Dominion Energy Gas Holdings, LLC | Pension Benefits | Other operations and maintenance
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost								(37,000,000)	(45,000,000)	(38,000,000)
Dominion Energy Gas Holdings, LLC | Other Postretirement Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual return (loss) on plan assets								41,000,000	23,000,000
Expected return on pension and other postretirement plan assets								24,000,000	23,000,000	$ 24,000,000
Net actuarial loss				$ 3,000,000				3,000,000
Actuarial (gains) losses during the year								$ 34,000,000	$ 28,000,000
Discount rate percentage								4.47%	4.93%	4.40%
Discount rate percentage				3.76%				3.76%	4.47%
Contributions to qualified defined benefit pension plans								$ 12,000,000	$ 12,000,000
Net periodic benefit cost								(9,000,000)	(2,000,000)	$ (2,000,000)
Dominion Energy Gas Holdings, LLC | Collective Bargaining Agreement | Pension Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gains) losses during the year									24,000,000
Dominion Energy Gas Holdings, LLC | Collective Bargaining Agreement | Other Postretirement Benefits
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gains) losses during the year									9,000,000
Virginia Electric and Power Company
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts recognized in employer matching contributions								19,000,000	19,000,000	18,000,000
Virginia Electric and Power Company | Special Termination Benefits | Organizational Design Initiative
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Organizational design initiative									33,000,000
Organizational design initiative, after tax									20,000,000
Virginia Electric and Power Company | Other operations and maintenance | Dominion Retiree Health And Welfare Plan
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost								(42,000,000)	(29,000,000)	(16,000,000)
Virginia Electric and Power Company | Pension Benefits | Other operations and maintenance
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost								$ 110,000,000	$ 79,000,000	$ 97,000,000

Employee Benefit Plans (Summary

Employee Benefit Plans (Summary of Changes in Pension and Other Postretirement Benefit Plans) (Detail) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes in fair value of plan assets:
Actual return (loss) on plan assets		$ 1,600,000,000	$ 534,000,000
Employer contributions		0
Dominion Energy Gas Holdings, LLC
Changes in fair value of plan assets:
Actual return (loss) on plan assets		335,000,000	130,000,000
Employer contributions		0
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year		8,132,000,000	6,391,000,000
Dominion Energy Questar Combination			817,000,000
Service cost		138,000,000	118,000,000	$ 126,000,000
Interest cost		345,000,000	317,000,000	287,000,000
Benefits paid		(323,000,000)	(286,000,000)
Actuarial (gains) losses during the year		830,000,000	784,000,000
Plan amendments	[1]	5,000,000
Settlements and curtailments	[2]	(75,000,000)	(9,000,000)
Benefit obligation at end of year		9,052,000,000	8,132,000,000	6,391,000,000
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year		7,016,000,000	6,166,000,000
Dominion Energy Questar Combination			704,000,000
Actual return (loss) on plan assets		1,327,000,000	426,000,000
Employer contributions		118,000,000	15,000,000
Benefits paid		(323,000,000)	(286,000,000)
Settlements	[2]	(76,000,000)	(9,000,000)
Fair value of plan assets at end of year		8,062,000,000	7,016,000,000	6,166,000,000
Funded status at end of year		(990,000,000)	(1,116,000,000)
Noncurrent pension and other postretirement benefit assets		1,117,000,000	930,000,000
Other current liabilities		(8,000,000)	(43,000,000)
Noncurrent pension and other postretirement benefit liabilities		(2,099,000,000)	(2,003,000,000)
Net amount recognized		$ (990,000,000)	$ (1,116,000,000)
Changes in benefit obligation:
Weighted average rate of increase for compensation		4.09%	4.09%
Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year		$ 683,000,000	$ 608,000,000
Service cost		15,000,000	13,000,000	15,000,000
Interest cost		30,000,000	30,000,000	27,000,000
Benefits paid		(33,000,000)	(32,000,000)
Actuarial (gains) losses during the year		78,000,000	64,000,000
Benefit obligation at end of year		773,000,000	683,000,000	608,000,000
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year		1,542,000,000	1,467,000,000
Actual return (loss) on plan assets		294,000,000	107,000,000
Benefits paid		(33,000,000)	(32,000,000)
Fair value of plan assets at end of year		1,803,000,000	1,542,000,000	1,467,000,000
Funded status at end of year		1,030,000,000	859,000,000
Noncurrent pension and other postretirement benefit assets		1,030,000,000	859,000,000
Net amount recognized		$ 1,030,000,000	$ 859,000,000
Changes in benefit obligation:
Discount rate		3.81%	4.50%
Weighted average rate of increase for compensation		4.11%	4.11%
Pension Benefits | Minimum
Changes in benefit obligation:
Discount rate		3.80%	3.31%
Pension Benefits | Maximum
Changes in benefit obligation:
Discount rate		3.81%	4.50%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year		$ 1,478,000,000	$ 1,430,000,000
Dominion Energy Questar Combination			85,000,000
Service cost		26,000,000	31,000,000	40,000,000
Interest cost		60,000,000	65,000,000	67,000,000
Benefits paid		(83,000,000)	(83,000,000)
Actuarial (gains) losses during the year		119,000,000	166,000,000
Plan amendments	[1]	(73,000,000)	(216,000,000)
Settlements and curtailments	[2]	2,000,000
Benefit obligation at end of year		1,529,000,000	1,478,000,000	1,430,000,000
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year		1,512,000,000	1,382,000,000
Dominion Energy Questar Combination			45,000,000
Actual return (loss) on plan assets		236,000,000	108,000,000
Employer contributions		13,000,000	12,000,000
Benefits paid		(32,000,000)	(35,000,000)
Fair value of plan assets at end of year		1,729,000,000	1,512,000,000	1,382,000,000
Funded status at end of year		200,000,000	34,000,000
Noncurrent pension and other postretirement benefit assets		261,000,000	148,000,000
Other current liabilities			(5,000,000)
Noncurrent pension and other postretirement benefit liabilities		(61,000,000)	(109,000,000)
Net amount recognized		$ 200,000,000	$ 34,000,000
Changes in benefit obligation:
Discount rate		3.76%
Weighted average rate of increase for compensation			3.29%
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of year		$ 320,000,000	$ 292,000,000
Service cost		4,000,000	5,000,000	7,000,000
Interest cost		12,000,000	14,000,000	14,000,000
Benefits paid		(19,000,000)	(19,000,000)
Actuarial (gains) losses during the year		34,000,000	28,000,000
Plan amendments	[1]	(61,000,000)
Benefit obligation at end of year		290,000,000	320,000,000	292,000,000
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year		299,000,000	283,000,000
Actual return (loss) on plan assets		41,000,000	23,000,000
Employer contributions		12,000,000	12,000,000
Benefits paid		(19,000,000)	(19,000,000)
Fair value of plan assets at end of year		333,000,000	299,000,000	$ 283,000,000
Funded status at end of year		43,000,000	(21,000,000)
Noncurrent pension and other postretirement benefit assets		57,000,000
Noncurrent pension and other postretirement benefit liabilities	[3]	(14,000,000)	(21,000,000)
Net amount recognized		$ 43,000,000	$ (21,000,000)
Changes in benefit obligation:
Discount rate		3.76%	4.47%
Other Postretirement Benefits | Minimum
Changes in benefit obligation:
Discount rate			3.92%
Weighted average rate of increase for compensation		3.95%
Other Postretirement Benefits | Maximum
Changes in benefit obligation:
Discount rate			4.47%
Weighted average rate of increase for compensation		4.11%
[1]	2017 amounts relate primarily to a plan amendment that changed post-65 retiree medical coverage for certain current and future Local 69 retirees effective July 1, 2017. 2016 amount relates primarily to a plan amendment that changed post-65 retiree medical coverage for certain current and future Local 50 retirees effective April 1, 2017.
[2]	2017 amount relates primarily to settlement and curtailment as a result of the voluntary and involuntary separation programs at Dominion Energy Questar. 2016 amount relates primarily to a settlement for certain executives.
[3]	Reflected in other deferred credits and other liabilities in Dominion Energy Gas' Consolidated Balance Sheets.

Employee Benefit Plans (Benefit

Employee Benefit Plans (Benefit Obligation in Excess of Plan Assets) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	$ 8,209	$ 7,386
Fair value of plan assets	6,103	5,340
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	191	470
Fair value of plan assets	156	356
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	157	320
Fair value of plan assets	$ 143	$ 299

Employee Benefit Plans (Accumul

Employee Benefit Plans (Accumulated Benefit Obligation in Excess of Plan Assets) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
General Discussion Of Pension And Other Postretirement Benefits [Abstract]
Accumulated benefit obligation	$ 7,392	$ 5,987
Fair value of plan assets	$ 6,103	$ 4,653

Employee Benefit Plans (Bene142

Employee Benefit Plans (Benefit Payments Expected Future Service) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 373
2,019	378
2,020	402
2,021	418
2,022	434
2023-2027	2,437
Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
2,018	35
2,019	37
2,020	38
2,021	39
2,022	41
2023-2027	214
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
2,018	99
2,019	101
2,020	102
2,021	102
2,022	102
2023-2027	486
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
2,018	19
2,019	19
2,020	20
2,021	20
2,022	20
2023-2027	$ 94

Employee Benefit Plans (Fair va

Employee Benefit Plans (Fair values of pension and post retirement plan assets by asset category) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Total investments		$ 1,378	$ 1,078
Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total investments		1,828	1,557
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		8,062	7,016	$ 6,166
Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,803	1,542	1,467
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,729	1,512	1,382
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		333	299	$ 283
Collective Bargaining Agreement | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		4,878	4,233
Total recorded at NAV	[1]	3,169	2,765
Total investments	[2]	8,047	6,998
Collective Bargaining Agreement | Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,090	930
Total recorded at NAV	[1]	709	608
Total investments	[3]	1,799	1,538
Collective Bargaining Agreement | Pension Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		18	14
Collective Bargaining Agreement | Pension Benefits | Cash equivalents and other | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		4	3
Collective Bargaining Agreement | Pension Benefits | Equity securities: | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,902	1,705
Collective Bargaining Agreement | Pension Benefits | Equity securities: | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,151	928
Collective Bargaining Agreement | Pension Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		425	375
Collective Bargaining Agreement | Pension Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		257	203
Collective Bargaining Agreement | Pension Benefits | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		352	334
Collective Bargaining Agreement | Pension Benefits | Insurance contracts | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		79	73
Collective Bargaining Agreement | Pension Benefits | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		770	717
Collective Bargaining Agreement | Pension Benefits | Corporate debt instruments | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		172	158
Collective Bargaining Agreement | Pension Benefits | Government securities
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		685	535
Collective Bargaining Agreement | Pension Benefits | Government securities | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		153	118
Collective Bargaining Agreement | Pension Benefits | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	2,272	1,960
Collective Bargaining Agreement | Pension Benefits | Common/collective trust funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	509	430
Collective Bargaining Agreement | Pension Benefits | Real Estate Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	111	121
Collective Bargaining Agreement | Pension Benefits | Real Estate Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	25	27
Collective Bargaining Agreement | Pension Benefits | Private Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	606	506
Collective Bargaining Agreement | Pension Benefits | Private Equity Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	135	111
Collective Bargaining Agreement | Pension Benefits | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	161	153
Collective Bargaining Agreement | Pension Benefits | Fixed Income Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	36	34
Collective Bargaining Agreement | Pension Benefits | Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	19	25
Collective Bargaining Agreement | Pension Benefits | Hedge Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	4	6
Collective Bargaining Agreement | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		944	808
Total recorded at NAV	[1]	783	702
Total investments	[4]	1,727	1,510
Collective Bargaining Agreement | Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		163	145
Total recorded at NAV	[1]	170	154
Total investments		333	299
Collective Bargaining Agreement | Other Postretirement Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		3	2
Collective Bargaining Agreement | Other Postretirement Benefits | Equity securities: | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		636	571
Collective Bargaining Agreement | Other Postretirement Benefits | Equity securities: | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		196	143
Collective Bargaining Agreement | Other Postretirement Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		130	121
Collective Bargaining Agreement | Other Postretirement Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		33	24
Collective Bargaining Agreement | Other Postretirement Benefits | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		21	19
Collective Bargaining Agreement | Other Postretirement Benefits | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		46	42
Collective Bargaining Agreement | Other Postretirement Benefits | Government securities
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		42	31
Collective Bargaining Agreement | Other Postretirement Benefits | Common/collective trust funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	689	621
Collective Bargaining Agreement | Other Postretirement Benefits | Common/collective trust funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	154	140
Collective Bargaining Agreement | Other Postretirement Benefits | Real Estate Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	9	9
Collective Bargaining Agreement | Other Postretirement Benefits | Real Estate Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	1	1
Collective Bargaining Agreement | Other Postretirement Benefits | Private Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	73	59
Collective Bargaining Agreement | Other Postretirement Benefits | Private Equity Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	15	12
Collective Bargaining Agreement | Other Postretirement Benefits | Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	11	12
Collective Bargaining Agreement | Other Postretirement Benefits | Fixed Income Funds | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]		1
Collective Bargaining Agreement | Other Postretirement Benefits | Hedge Funds
Defined Benefit Plan Disclosure [Line Items]
Total recorded at NAV	[1]	1	1
Collective Bargaining Agreement | Level 1 | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		3,121	2,693
Collective Bargaining Agreement | Level 1 | Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		697	592
Collective Bargaining Agreement | Level 1 | Pension Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		18	12
Collective Bargaining Agreement | Level 1 | Pension Benefits | Cash equivalents and other | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		4	3
Collective Bargaining Agreement | Level 1 | Pension Benefits | Equity securities: | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,902	1,705
Collective Bargaining Agreement | Level 1 | Pension Benefits | Equity securities: | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,151	928
Collective Bargaining Agreement | Level 1 | Pension Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		425	375
Collective Bargaining Agreement | Level 1 | Pension Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		257	203
Collective Bargaining Agreement | Level 1 | Pension Benefits | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		41	35
Collective Bargaining Agreement | Level 1 | Pension Benefits | Corporate debt instruments | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		9	8
Collective Bargaining Agreement | Level 1 | Pension Benefits | Government securities
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		9	13
Collective Bargaining Agreement | Level 1 | Pension Benefits | Government securities | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		2	3
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		836	718
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		163	145
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1	1
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Equity securities: | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		636	571
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Equity securities: | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		196	143
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | U.S.
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		130	121
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Equity securities: | Dominion Energy Gas Holdings, LLC | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		33	24
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		2	2
Collective Bargaining Agreement | Level 1 | Other Postretirement Benefits | Government securities
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1	1
Collective Bargaining Agreement | Level 2 | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		1,757	1,540
Collective Bargaining Agreement | Level 2 | Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		393	338
Collective Bargaining Agreement | Level 2 | Pension Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value			2
Collective Bargaining Agreement | Level 2 | Pension Benefits | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		352	334
Collective Bargaining Agreement | Level 2 | Pension Benefits | Insurance contracts | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		79	73
Collective Bargaining Agreement | Level 2 | Pension Benefits | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		729	682
Collective Bargaining Agreement | Level 2 | Pension Benefits | Corporate debt instruments | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		163	150
Collective Bargaining Agreement | Level 2 | Pension Benefits | Government securities
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		676	522
Collective Bargaining Agreement | Level 2 | Pension Benefits | Government securities | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		151	115
Collective Bargaining Agreement | Level 2 | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		108	90
Collective Bargaining Agreement | Level 2 | Other Postretirement Benefits | Cash equivalents and other
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		2	1
Collective Bargaining Agreement | Level 2 | Other Postretirement Benefits | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		21	19
Collective Bargaining Agreement | Level 2 | Other Postretirement Benefits | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		44	40
Collective Bargaining Agreement | Level 2 | Other Postretirement Benefits | Government securities
Defined Benefit Plan Disclosure [Line Items]
Total recorded at fair value		$ 41	$ 30
[1]	These investments that are measured at fair value using the NAV per share (or its equivalent) as a practical expedient which are not required to be categorized in the fair value hierarchy.
[2]	Excludes net assets related to pending sales of securities of $11 million, net accrued income of $19 million, and includes net assets related to pending purchases of securities of $15 million at December 31, 2017. Excludes net assets related to pending sales of securities of $46 million, net accrued income of $19 million, and includes net assets related to pending purchases of securities of $47 million at December 31, 2016.
[3]	Excludes net assets related to pending sales of securities of $3 million, net accrued income of $4 million, and includes net assets related to pending purchases of securities of $3 million at December 31, 2017. Excludes net assets related to pending sales of securities of $10 million, net accrued income of $4 million, and includes net assets related to pending purchases of securities of $10 million at December 31, 2016.
[4]	Excludes net assets related to pending sales of securities of $1 million, net accrued income of $2 million, and includes net assets related to pending purchases of securities of $1 million at December 31, 2017. Excludes net assets related to pending sales of securities of $5 million, net accrued income of $2 million, and includes net assets related to pending purchases of securities of $5 million at December 31, 2016.

Employee Benefit Plans (Fair144

Employee Benefit Plans (Fair values of pension and post retirement plan assets by asset category) (Parenthetical) (Detail) - Collective Bargaining Agreement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Pending sales of securities	$ 11	$ 46
Net accrued income	19	19
Pending purchases of securities	15	47
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Pending sales of securities	1	5
Net accrued income	2	2
Pending purchases of securities	1	5
Dominion Energy Gas Holdings, LLC | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Pending sales of securities	3	10
Net accrued income	4	4
Pending purchases of securities	$ 3	$ 10

Employee Benefit Plans (Net Per

Employee Benefit Plans (Net Periodic Benefit (Credit) Cost and Amounts Recognized in Other Comprehensive Income and Regulatory Assets and Liabilities) (Detail) - USD ($) $ in Millions		Sep. 30, 2017	Jun. 30, 2017	Jan. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expected return on plan assets					$ (767)	$ (691)
Dominion Energy Gas Holdings, LLC
Expected return on plan assets					(165)	(157)
Pension Benefits
Service cost					138	118	$ 126
Interest cost					345	317	287
Expected return on plan assets					(639)	(573)	(531)
Amortization of prior service (credit) cost					1	1	2
Amortization of net actuarial loss					162	111	160
Settlements and curtailments						1
Net periodic benefit (credit) cost					7	(25)	44
Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities:
Current year net actuarial (gain) loss					142	931	159
Prior service (credit) cost					5
Settlements and curtailments					1	(1)
Amortization of net actuarial loss					(162)	(111)	(160)
Amortization of prior service credit (cost)					(1)	(1)	(2)
Total recognized in other comprehensive income and regulatory assets and liabilities					$ (15)	$ 818	$ (3)
Significant assumptions used to determine periodic cost:
Discount rate		4.05%	4.05%	4.51%		4.46%	4.40%
Expected long-term rate of return on plan assets					8.75%	8.75%	8.75%
Weighted average rate of increase for compensation					4.09%	4.22%	4.22%
Pension Benefits | Dominion Energy Gas Holdings, LLC
Service cost					$ 15	$ 13	$ 15
Interest cost					30	30	27
Expected return on plan assets					(141)	(134)	(126)
Amortization of prior service (credit) cost							1
Amortization of net actuarial loss					16	13	20
Net periodic benefit (credit) cost					(80)	(78)	(63)
Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities:
Current year net actuarial (gain) loss					(75)	91	97
Amortization of net actuarial loss					(16)	(13)	(20)
Amortization of prior service credit (cost)							(1)
Total recognized in other comprehensive income and regulatory assets and liabilities					$ (91)	$ 78	$ 76
Significant assumptions used to determine periodic cost:
Discount rate					4.50%	4.99%	4.40%
Expected long-term rate of return on plan assets					8.75%	8.75%	8.75%
Weighted average rate of increase for compensation					4.11%	3.93%	3.93%
Pension Benefits | Minimum
Significant assumptions used to determine periodic cost:
Discount rate					3.31%	2.87%
Pension Benefits | Maximum
Significant assumptions used to determine periodic cost:
Discount rate					4.50%	4.99%
Other Postretirement Benefits
Service cost					$ 26	$ 31	$ 40
Interest cost					60	65	67
Expected return on plan assets					(128)	(118)	(117)
Amortization of prior service (credit) cost					(51)	(35)	(27)
Amortization of net actuarial loss					13	8	6
Net periodic benefit (credit) cost					(80)	(49)	(31)
Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities:
Current year net actuarial (gain) loss					12	178	(18)
Prior service (credit) cost					(73)	(216)	(31)
Settlements and curtailments					2
Amortization of net actuarial loss					(13)	(8)	(6)
Amortization of prior service credit (cost)					51	35	27
Total recognized in other comprehensive income and regulatory assets and liabilities					$ (21)	$ (11)	$ (28)
Significant assumptions used to determine periodic cost:
Discount rate							4.40%
Expected long-term rate of return on plan assets					8.50%	8.50%	8.50%
Weighted average rate of increase for compensation					3.29%	4.22%	4.22%
Healthcare cost trend rate					7.00%	7.00%	7.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	[1]				5.00%	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	[1],[2]				2,021	2,020	2,019
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Service cost					$ 4	$ 5	$ 7
Interest cost					12	14	14
Expected return on plan assets					(24)	(23)	(24)
Amortization of prior service (credit) cost					(3)	1	(1)
Amortization of net actuarial loss					2	1	2
Net periodic benefit (credit) cost					(9)	(2)	(2)
Changes in plan assets and benefit obligations recognized in other comprehensive income and regulatory assets and liabilities:
Current year net actuarial (gain) loss					18	28	(9)
Prior service (credit) cost					(61)
Amortization of net actuarial loss					(2)	(1)	(2)
Amortization of prior service credit (cost)					3	(1)	1
Total recognized in other comprehensive income and regulatory assets and liabilities					$ (42)	$ 26	$ (10)
Significant assumptions used to determine periodic cost:
Discount rate					4.47%	4.93%	4.40%
Expected long-term rate of return on plan assets					8.50%	8.50%	8.50%
Weighted average rate of increase for compensation					4.11%	3.93%	3.93%
Healthcare cost trend rate					7.00%	7.00%	7.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	[1]				5.00%	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	[1]				2,021	2,020	2,019
Other Postretirement Benefits | Minimum
Significant assumptions used to determine periodic cost:
Discount rate					3.92%	3.56%
Other Postretirement Benefits | Maximum
Significant assumptions used to determine periodic cost:
Discount rate					4.47%	4.94%
[1]	Assumptions used to determine net periodic cost for the following year.
[2]	The Society of Actuaries model used to determine healthcare cost trend rates was updated in 2014. The new model converges to the ultimate trend rate much more quickly than previous models.

Employee Benefit Plans (AOCI an

Employee Benefit Plans (AOCI and regulatory assets and liabilities that have not been recognized as components of periodic benefit (credit) cost) (Detail) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		$ 659	$ 799
Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		98	123
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		3,181	3,200
Prior service (credit) cost		8	4
Total	[1]	3,189	3,204
Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		367	458
Total	[2]	367	458
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		283	283
Prior service (credit) cost		(440)	(419)
Total	[1]	(157)	(136)
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		76	60
Prior service (credit) cost		(52)	7
Total	[2]	$ 24	$ 67
[1]	As of December 31, 2017, of the $3.2 billion and $(157) million related to pension benefits and other postretirement benefits, $1.9 billion and $(87) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities. As of December 31, 2016, of the $3.2 billion and $(136) million related to pension benefits and other postretirement benefits, $1.9 billion and $(103) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities.
[2]	As of December 31, 2017, of the $367 million related to pension benefits, $134 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $24 million related to other postretirement benefits is included entirely in regulatory assets and liabilities. As of December 31, 2016, of the $458 million related to pension benefits, $167 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $67 million related to other postretirement benefits is included entirely in regulatory assets and liabilities.

Employee Benefit Plans (AOCI147

Employee Benefit Plans (AOCI and regulatory assets and liabilities that have not been recognized as components of periodic benefit (credit) cost) (Parenthetical) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total	[1]	$ 3,189	$ 3,204
Amount included in AOCI		1,900	1,900
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total	[1]	(157)	(136)
Amount included in AOCI		(87)	(103)
Dominion Energy Gas Holdings, LLC | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total	[2]	367	458
Amount included in AOCI		134	167
Dominion Energy Gas Holdings, LLC | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Total	[2]	$ 24	$ 67
[1]	As of December 31, 2017, of the $3.2 billion and $(157) million related to pension benefits and other postretirement benefits, $1.9 billion and $(87) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities. As of December 31, 2016, of the $3.2 billion and $(136) million related to pension benefits and other postretirement benefits, $1.9 billion and $(103) million, respectively, are included in AOCI, with the remainder included in regulatory assets and liabilities.
[2]	As of December 31, 2017, of the $367 million related to pension benefits, $134 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $24 million related to other postretirement benefits is included entirely in regulatory assets and liabilities. As of December 31, 2016, of the $458 million related to pension benefits, $167 million is included in AOCI, with the remainder included in regulatory assets and liabilities; the $67 million related to other postretirement benefits is included entirely in regulatory assets and liabilities.

Employee Benefit Plans (Compone

Employee Benefit Plans (Components of AOCI and Regulatory Assets and Liabilities) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		$ (25)
Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss		$ (3)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 193
Prior service (credit) cost	1
Pension Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	19
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	11
Prior service (credit) cost	(52)
Other Postretirement Benefits | Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	3
Prior service (credit) cost	$ (4)

Employee Benefit Plans (Effect

Employee Benefit Plans (Effect of One Percentage Point Change on Benefit Plans) (Detail) - Other Postretirement Benefits $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Defined Benefit Plan Disclosure [Line Items]
Effect of one percentage point increase on total of service and interest cost components	$ 24
Effect of one percentage point increase on other postretirement benefit obligation	158
Effect of one percentage point decrease on total of service and interest cost components	(15)
Effect of one percentage point decrease on other postretirement benefit obligation	(132)
Dominion Energy Gas Holdings, LLC
Defined Benefit Plan Disclosure [Line Items]
Effect of one percentage point increase on total of service and interest cost components	4
Effect of one percentage point increase on other postretirement benefit obligation	31
Effect of one percentage point decrease on total of service and interest cost components	(3)
Effect of one percentage point decrease on other postretirement benefit obligation	$ (26)

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Detail)

1 Months Ended

12 Months Ended

Dec. 31, 2017USD ($)siteFacilityParties

Sep. 30, 2017

Jul. 31, 2017

Jun. 30, 2017

May 31, 2017Counts

Apr. 30, 2017PetitionStation

Mar. 31, 2017Counts

Aug. 31, 2016T

Jul. 31, 2016Parties

Oct. 31, 2015PartsPerBillion

Jun. 30, 2015Parties

Apr. 30, 2015Facility

Oct. 31, 2014Facilitygal

Jun. 30, 2014

Sep. 30, 2013Bcfe

Dec. 31, 2017USD ($)siteFacility

Dec. 31, 2016USD ($)

Dec. 31, 2015USD ($)

Apr. 30, 2016USD ($)

Jul. 31, 2013Counts

Loss Contingencies [Line Items]

ARO incurred

$ 37,000,000

$ 204,000,000

[1]

Virginia Electric and Power Company

Loss Contingencies [Line Items]

ARO incurred

11,000,000

9,000,000

Dominion Energy Gas Holdings, LLC

Loss Contingencies [Line Items]

ARO incurred

$ 2,000,000

6,000,000

Future Ash Pond and Landfill Closure Costs

Loss Contingencies [Line Items]

ARO incurred

238,000,000

$ 386,000,000

Increase in Property, Plant and Equipment [Member]

Loss Contingencies [Line Items]

ARO incurred

17,000,000

166,000,000

Reversal of Contingent Liability [Member]

Loss Contingencies [Line Items]

ARO incurred

121,000,000

Increase in Regulatory Assets

Loss Contingencies [Line Items]

ARO incurred

24,000,000

Other operations and maintenance

Loss Contingencies [Line Items]

ARO incurred

$ 197,000,000

$ 99,000,000

CWA | Minimum | Virginia Electric and Power Company | Possum Point Power Station | Judicial Ruling [Member]

Loss Contingencies [Line Items]

Additional specific sediment, water and aquatic life monitoring period

2 years

CWA | EPA | Final Rule to Revise Effluent Limitations Guidelines for Steam Electric Power Generating Category

Loss Contingencies [Line Items]

Compliance date

2023-12

CWA | EPA | 2015 Effluent Limitations Guidelines Rule for Steam Electric Power Generating Category

Loss Contingencies [Line Items]

Compliance date

2020-11

Ozone Standards | EPA | Maximum

Loss Contingencies [Line Items]

Maximum period to develop plans to address new standard

3 years

Unfavorable Regulatory Action | Maximum | Non-FTA

Loss Contingencies [Line Items]

Authorization export approval of natural gas per day | Bcfe

0.77

Unfavorable Regulatory Action | EPA

Loss Contingencies [Line Items]

Significant emission rate per rear CO2 equivalent | T

75,000

Electric generating station facilities heightened entrainment analysis per day | gal

125,000,000

Unfavorable Regulatory Action | Regulations To Reduce Nitrogen Oxideand Volatile Organic Compounds Emissions [Member] | Pennsylvania Department Of Environmental Protection [Member] | Dominion Gas Holdings, LLC

Loss Contingencies [Line Items]

Estimated compliance costs

$ 35,000,000

Unfavorable Regulatory Action | CWA

Loss Contingencies [Line Items]

Number of facilities that may be subject to final regulations | Facility

13

Unfavorable Regulatory Action | CWA | Virginia Electric and Power Company

Loss Contingencies [Line Items]

Number of facilities that may be subject to final regulations | Facility

11

Unfavorable Regulatory Action | CWA | EPA | Final Rule to Revise Effluent Limitations Guidelines for Steam Electric Power Generating Category

Loss Contingencies [Line Items]

Number of facilities that maybe subject to additional wastewater treatment requirements | Facility

8

8

Number of separate petitions for reconsideration granted | Petition

2

Unfavorable Regulatory Action | Coal Tar and Other Potentially Harmful Materials | EPA

Loss Contingencies [Line Items]

Number of former manufactured gas plant sites | site

19

19

Unfavorable Regulatory Action | Coal Tar and Other Potentially Harmful Materials | EPA | Former Gas Plant Site with Post Closure Groundwater Monitoring Program

Loss Contingencies [Line Items]

Number of former sites | site

1

Unfavorable Regulatory Action | Coal Tar and Other Potentially Harmful Materials | EPA | Virginia Electric and Power Company

Loss Contingencies [Line Items]

Number of former manufactured gas plant sites | site

3

3

Unfavorable Regulatory Action | Coal Tar and Other Potentially Harmful Materials | EPA | Dominion Energy Gas Holdings, LLC

Loss Contingencies [Line Items]

Number of former manufactured gas plant sites | site

12

12

Unfavorable Regulatory Action | Coal Tar and Other Potentially Harmful Materials | EPA | Minimum | Virginia Electric and Power Company

Loss Contingencies [Line Items]

Estimated compliance costs

$ 1,000,000

$ 1,000,000

Unfavorable Regulatory Action | Coal Tar and Other Potentially Harmful Materials | EPA | Maximum | Virginia Electric and Power Company

Loss Contingencies [Line Items]

Estimated compliance costs

22,000,000

22,000,000

Unfavorable Regulatory Action | MATS | EPA

Loss Contingencies [Line Items]

Extension period for MATS compliance

1 year

Requested compliance extension under EPA Administrative Order

1 year

Unfavorable Regulatory Action | MATS | EPA | Virginia Electric and Power Company

Loss Contingencies [Line Items]

Number of effective days to operate power station units

90 days

Period to be in service following receipt of all required permits

23 months

Unfavorable Regulatory Action | Ozone Standards | EPA

Loss Contingencies [Line Items]

Standard emission level prior to revision | PartsPerBillion

75

Revised emission standard level | PartsPerBillion

70

Unfavorable Regulatory Action | Ozone Standards | EPA | Minimum

Loss Contingencies [Line Items]

Estimated compliance costs

25,000,000

25,000,000

Unfavorable Regulatory Action | Ozone Standards | EPA | Maximum

Loss Contingencies [Line Items]

Estimated compliance costs

35,000,000

$ 35,000,000

Unfavorable Regulatory Action | Oil And Gas New Source Performance Standards [Member]

Loss Contingencies [Line Items]

Number of period court appeals DC vacated stay

90 days

Unfavorable Regulatory Action | Oil And Gas New Source Performance Standards [Member] | EPA

Loss Contingencies [Line Items]

Requested compliance extension under EPA Administrative Order

2 years

EPA notice issued reviewing month and year

2017-04

Number of period EPA published notice of reconsideration and partial stay

90 days

Unfavorable Regulatory Action | CCR | EPA | Virginia Electric and Power Company | Environmental Protection Agency Final Rule Regulating Management of CCRs | Facilities Subject to Coal Combustion Residual Final Rule

Loss Contingencies [Line Items]

Number of facilities with CCR | Facility

8

Number of stations | Station

4

Breach of Contract Lawsuit | DETI | Pending Litigation [Member]

Loss Contingencies [Line Items]

Total number of counts in complaint | Counts

8

Accrued liability for legal matter

$ 2,000,000

$ 2,000,000

Breach of Contract Lawsuit | DETI | Judicial Ruling [Member]

Loss Contingencies [Line Items]

Number of counts dismissed | Counts

3

Breach of Contract Lawsuit | DETI | Settled Litigation

Loss Contingencies [Line Items]

Number of claims withdrew | Counts

1

Liquefaction Project | Federal Energy Regulatory Commission | Cove Point | Pending Litigation [Member]

Loss Contingencies [Line Items]

Number of parties | Parties

2

Liquefaction Project | Federal Energy Regulatory Commission | Cove Point | Judicial Ruling [Member]

Loss Contingencies [Line Items]

Number of parties | Parties

1

1

1

[1]

Primarily reflects AROs assumed in the Dominion Energy Questar Combination. See Note 3 for further information.

Commitments and Contingencie151

Commitments and Contingencies (Nuclear Operations) (Narrative) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Amount of coverage purchased from commercial insurance pools	$ 450,000,000
Maximum assessment for premiums on insurance policy	86,000,000
Maximum assessment for insurance policy	22,000,000
Spent Nuclear Fuel
Loss Contingencies [Line Items]
Receivables	46,000,000	$ 56,000,000
Nuclear Obligations
Loss Contingencies [Line Items]
Maximum liability protection per nuclear incident amount	$ 13,440,000,000
Inflationary provision adjustment period	5 years
Maximum
Loss Contingencies [Line Items]
Amount that could be assessed for each licensed reactor	$ 127,000,000
Amount that could be assessed for each licensed reactor per reactor	19,000,000
Millstone Unit 1
Loss Contingencies [Line Items]
Minimum financial assurance	2,700,000,000
Millstone
Loss Contingencies [Line Items]
Settlement amount	14,000,000	22,000,000	$ 17,000,000
Surry and North Anna
Loss Contingencies [Line Items]
Settlement amount	22,000,000	30,000,000	$ 8,000,000
Virginia Electric and Power Company
Loss Contingencies [Line Items]
Maximum assessment for premiums on insurance policy	50,000,000
Maximum assessment for insurance policy	10,000,000
Virginia Electric and Power Company | Spent Nuclear Fuel
Loss Contingencies [Line Items]
Receivables	30,000,000	$ 37,000,000
Virginia Electric and Power Company | Kewaunee
Loss Contingencies [Line Items]
Minimum financial assurance	$ 1,800,000,000

Commitments and Contingencie152

Commitments and Contingencies (Nuclear Insurance) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Millstone
Guarantor Obligations [Line Items]
Property insurance coverage	$ 1,700
Kewaunee
Guarantor Obligations [Line Items]
Property insurance coverage	1,060
Surry | Virginia Electric and Power Company
Guarantor Obligations [Line Items]
Property insurance coverage	1,700	[1]
North Anna | Virginia Electric and Power Company
Guarantor Obligations [Line Items]
Property insurance coverage	$ 1,700	[1]
[1]	Surry and North Anna share a blanket property limit of $200 million.

Commitments and Contingencie153

Commitments and Contingencies (Nuclear Insurance) (Parenthetical) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Surry and North Anna
Guarantor Obligations [Line Items]
Coverage amount	$ 200

Commitment and Contingencies (S

Commitment and Contingencies (Schedule of Long Term Purchase Commitments) (Detail) - Virginia Electric and Power Company - Purchased electric capacity $ in Millions	Dec. 31, 2017USD ($)	[1]
Long-term Purchase Commitment [Line Items]
2,018	$ 93
2,019	61
2,020	52
2,021	46
2,022	0
Thereafter	0
Total	$ 252
[1]	Commitments represent estimated amounts payable for capacity under a power purchase contract with a qualifying facility and an independent power producer, which ends in 2021. Capacity payments under the contract are generally based on fixed dollar amounts per month, subject to escalation using broad-based economic indices. At December 31, 2017, the present value of Virginia Power's total commitment for capacity payments is $221 million. Capacity payments totaled $114 million, $248 million, and $305 million, and energy payments totaled $72 million, $126 million, and $198 million for the years ended 2017, 2016 and 2015, respectively.

Commitment and Contingencies155

Commitment and Contingencies (Schedule of Long Term Purchase Commitments) (Parenthetical) (Detail) - Virginia Electric and Power Company - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-term Purchase Commitment [Line Items]
Present value of total commitment for capacity payments	$ 221
Purchased electric capacity
Long-term Purchase Commitment [Line Items]
Payments	114	$ 248	$ 305
Energy payments
Long-term Purchase Commitment [Line Items]
Payments	$ 72	$ 126	$ 198

Commitments and Contingencie156

Commitments and Contingencies (Lease Commitments) (Detail) $ in Millions	Dec. 31, 2017USD ($)
Loss Contingencies [Line Items]
2,018	$ 68	[1]
2,019	63	[1]
2,020	56	[1]
2,021	48	[1]
2,022	39	[1]
Thereafter	361	[1]
Total	635	[1]
Virginia Electric and Power Company
Loss Contingencies [Line Items]
2,018	34
2,019	31
2,020	27
2,021	22
2,022	15
Thereafter	28
Total	157
Dominion Gas Holdings, LLC
Loss Contingencies [Line Items]
2,018	15
2,019	13
2,020	10
2,021	9
2,022	7
Thereafter	41
Total	$ 95
[1]	Amounts include a lease agreement for the Dominion Energy Questar corporate office, which is accounted for as a capital lease. At December 31, 2017 and 2016, the Consolidated Balance Sheets include $27 million and $30 million, respectively, in property, plant and equipment and $33 million and $35 million, respectively, in other deferred credits and other liabilities. The Consolidated Statements of Income include $3 million and less than $1 million recorded in depreciation, depletion and amortization for the years ended December 31, 2017 and 2016.

Commitments and Contingencie157

Commitments and Contingencies (Lease Commitments) (Parenthetical) (Detail) - Dominion Questar Corporation - Corporate office - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Amount included in property plant and equipment	$ 27	$ 30
Amount included in other deferred credits and other liabilities	33	35
Amount recorded in depreciation, depletion and amortization (less than $1 million)	$ 3	$ 1

Commitments and Contingencie158

Commitments and Contingencies (Lease Commitments) (Narrative) (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Rental expense		$ 113	$ 104	$ 99
Corporate office | Agreement with Lessor to Construct and Lease Corporate Office Property
Loss Contingencies [Line Items]
Requested cash draws from lessor to fund project costs		139
Required percentage payment of funded amount under certain events of default	89.90%
Required percentage payment for specific full recourse events	100.00%
Lease term	5 years
Extension term of lease	5 years
Required percentage payment to lessor for difference between project costs and sales proceeds	87.00%
Virginia Electric and Power Company
Loss Contingencies [Line Items]
Rental expense		57	52	51
Dominion Gas Holdings, LLC
Loss Contingencies [Line Items]
Rental expense		$ 34	$ 37	$ 37
Lessor | Corporate office | Agreement with Lessor to Construct and Lease Corporate Office Property
Loss Contingencies [Line Items]
Amount of financing commitments to fund estimated project costs	$ 365

Commitments and Contingencie159

Commitments and Contingencies (Guarantees, Surety Bonds and Letters of Credit) (Detail) - USD ($)		1 Months Ended	12 Months Ended
		Oct. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Facility Limit			$ 5,500,000,000	$ 5,500,000,000
Maximum Exposure	[1]		5,771,000,000
Cove Point
Guarantor Obligations [Line Items]
Maximum Exposure	[2]		1,900,000,000
Virginia Electric and Power Company
Guarantor Obligations [Line Items]
Facility Limit	[3]		5,500,000,000	5,500,000,000
Dominion Energy Gas Holdings, LLC
Guarantor Obligations [Line Items]
Facility Limit	[4]		1,500,000,000	$ 1,500,000,000
Nuclear Obligations
Guarantor Obligations [Line Items]
Maximum Exposure	[5]		227,000,000
Commodity Transactions
Guarantor Obligations [Line Items]
Maximum Exposure	[6]		2,027,000,000
Surety Bond [Member]
Guarantor Obligations [Line Items]
Maximum Exposure			153,000,000
Surety Bond [Member] | Virginia Electric and Power Company
Guarantor Obligations [Line Items]
Maximum Exposure			63,000,000
Surety Bond [Member] | Dominion Energy Gas Holdings, LLC
Guarantor Obligations [Line Items]
Maximum Exposure			24,000,000
Financial Standby Letter of Credit [Member]
Guarantor Obligations [Line Items]
Maximum Exposure			76,000,000
Debt [Member] | Virginia Electric and Power Company
Guarantor Obligations [Line Items]
Maximum Exposure			14,000,000
Solar
Guarantor Obligations [Line Items]
Maximum Exposure	[7]		1,064,000,000
Other
Guarantor Obligations [Line Items]
Maximum Exposure	[8]		553,000,000
Revolving Credit Facility | Atlantic Coast Pipeline | Financial Guarantee [Member]
Guarantor Obligations [Line Items]
Facility Limit		$ 3,400,000,000	3,400,000,000
Revolving credit facility stated maturity date		Oct. 31, 2021
Maximum potential loss exposure, limited guarantee percentage		48.00%
Guarantee liability			28,000,000
Guarantee recorded amount			664,000,000
Equity Method Investee [Member] | Financial Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum Exposure			48,000,000
Affiliated Entity | Financial Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum Exposure			17,000,000
Minimum | Affiliated Entity | Financial Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum annual future contributions			4,000,000
Maximum | Affiliated Entity | Financial Guarantee [Member]
Guarantor Obligations [Line Items]
Maximum annual future contributions			$ 14,000,000
[1]	Excludes Dominion Energy's guarantee for the construction of the new corporate office property discussed further within Lease Commitments above.
[2]	Guarantees related to Cove Point, in support of terminal services, transportation and construction. Cove Point has two guarantees that have no maximum limit and, therefore, are not included in this amount.
[3]	The full amount of the facilities is available to Virginia Power, less any amounts outstanding to co-borrowers Dominion Energy, Dominion Energy Gas and Questar Gas. Sub-limits for Virginia Power are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Virginia Power was an aggregate $1.5 billion. If Virginia Power has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These facilities mature in April 2020, and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $2.0 billion (or the sub-limit, whichever is less) of letters of credit.
[4]	A maximum of a combined $1.5 billion of the facilities is available to Dominion Energy Gas, assuming adequate capacity is available after giving effect to uses by co-borrowers Dominion Energy, Virginia Power and Questar Gas. Sub-limits for Dominion Energy Gas are set within the facility limit but can be changed at the option of the Companies multiple times per year. At December 31, 2017, the sub-limit for Dominion Energy Gas was an aggregate $500 million. If Dominion Energy Gas has liquidity needs in excess of its sub-limit, the sub-limit may be changed or such needs may be satisfied through short-term intercompany borrowings from Dominion Energy. These credit facilities mature in April 2020 and can be used to support bank borrowings and the issuance of commercial paper, as well as to support up to $1.5 billion (or the sub-limit, whichever is less) of letters of credit.
[5]	Guarantees related to certain DGI subsidiaries' regarding all aspects of running a nuclear facility.
[6]	Guarantees related to commodity commitments of certain subsidiaries. These guarantees were provided to counterparties in order to facilitate physical and financial transaction related commodities and services.
[7]	Includes guarantees to facilitate the development of solar projects. Also includes guarantees entered into by DGI on behalf of certain subsidiaries to facilitate the acquisition and development of solar projects.
[8]	Guarantees related to other miscellaneous contractual obligations such as leases, environmental obligations, construction projects and insurance programs. Due to the uncertainty of worker's compensation claims, the parental guarantee has no stated limit. Also included are guarantees related to certain DGI subsidiaries' obligations for equity capital contributions and energy generation associated with Fowler Ridge and NedPower. As of December 31, 2017, Dominion Energy's maximum remaining cumulative exposure under these equity funding agreements is $17 million through 2019 and its maximum annual future contributions could range from approximately $4 million to $14 million.

Credit Risk (Narrative) (Detail

Credit Risk (Narrative) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)CounterpartyCustomer	Dec. 31, 2016USD ($)
Concentration Risk And Guarantor Obligations [Line Items]
Gross credit exposure	$ 95
Additional collateral to be posted if the credit related contingent features were triggered	62	$ 3
Aggregate fair value of all derivative instruments with credit contingent provisions that are in a liability position	65	$ 9
Virginia Electric and Power Company
Concentration Risk And Guarantor Obligations [Line Items]
Gross credit exposure	60
Dominion Energy Gas Holdings, LLC
Concentration Risk And Guarantor Obligations [Line Items]
Gross credit exposure	$ 15
Credit Concentration Risk
Concentration Risk And Guarantor Obligations [Line Items]
Number of counterparties | Counterparty	0
Amount of exposure for single counterparty	$ 13
Credit Concentration Risk | Virginia Electric and Power Company
Concentration Risk And Guarantor Obligations [Line Items]
Number of counterparties | Counterparty	0
Amount of exposure for single counterparty	$ 13
Credit Concentration Risk | Dominion Energy Gas Holdings, LLC
Concentration Risk And Guarantor Obligations [Line Items]
Number of counterparties	0
Amount of exposure for single counterparty	$ 4
Credit Concentration Risk | Investment Grade | Investment Grade Counterparty
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	26.00%
Credit Concentration Risk | Investment Grade | Investment Grade Counterparty | Virginia Electric and Power Company
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	9.00%
Credit Concentration Risk | Investment Grade | Investment Grade Counterparty | Dominion Energy Gas Holdings, LLC
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	22.00%
Customer Concentration Risk | Sales Revenue, Net | Dominion Energy Gas Holdings, LLC
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	96.00%
Number of customers | Customer	289
Customer Concentration Risk | Sales Revenue, Net | Dominion Energy Gas Holdings, LLC | Ten Largest Customers
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	38.00%
Number of customers | Customer	10
Customer Concentration Risk | Sales Revenue, Net | Dominion Energy Gas Holdings, LLC | Thirty Largest Customers
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	68.00%
Number of customers | Customer	30
Customer Concentration Risk | Sales Revenue, Net | East Ohio
Concentration Risk And Guarantor Obligations [Line Items]
Concentration risk, percentage (percentage)	98.00%

Related-Party Transactions (Nar

Related-Party Transactions (Narrative) (Detail) - USD ($) shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Derivative Asset	$ 307,000,000	$ 279,000,000
Derivative Liabilities	284,000,000	155,000,000
Dominion Energy Gas Holdings, LLC
Related Party Transaction [Line Items]
Derivative Asset	32,000,000
Derivative Liabilities	8,000,000	11,000,000
Short term demand note	18,000,000	118,000,000
Dominion Energy Gas Holdings, LLC | Revolving Credit Facility | IRCA
Related Party Transaction [Line Items]
Short term demand note	$ 18,000,000	$ 118,000,000
Weighted- average interest rate percentage	1.60%	1.08%
Dominion Energy Gas Holdings, LLC | Pension Benefits | Amounts Associated with the Dominion Pension Plan
Related Party Transaction [Line Items]
Amounts due from Dominion, noncurrent	$ 734,000,000	$ 697,000,000
Dominion Energy Gas Holdings, LLC | Medical Coverage for Local retirees | Amounts Associated with the Dominion Retiree Health and Welfare Plan
Related Party Transaction [Line Items]
Amounts due from Dominion, noncurrent	7,000,000	2,000,000
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Derivative Asset	166,000,000	194,000,000
Derivative Liabilities	66,000,000	31,000,000
Short term demand note	33,000,000	262,000,000
Outstanding borrowings, net of repayments, under money pool for non-regulated subsidiaries	$ 0	$ 0
Issuance of common stock (in shares)	0	0	0
Virginia Electric and Power Company | Affiliated Entity
Related Party Transaction [Line Items]
Derivative Asset	$ 11,000,000	$ 41,000,000
Derivative Liabilities	5,000,000	8,000,000
Virginia Electric and Power Company | Principal Owner
Related Party Transaction [Line Items]
Short term demand note	$ 33,000,000	$ 262,000,000
Weighted- average interest rate percentage	1.65%	0.97%
Virginia Electric and Power Company | Pension Benefits | Amounts Associated with the Dominion Pension Plan
Related Party Transaction [Line Items]
Amounts due to Dominion, noncurrent	$ 505,000,000	$ 396,000,000
Virginia Electric and Power Company | Medical Coverage for Local retirees | Amounts Associated with the Dominion Retiree Health and Welfare Plan
Related Party Transaction [Line Items]
Amounts due from Dominion, noncurrent	$ 199,000,000	$ 130,000,000

Related-Party Transactions (Det

Related-Party Transactions (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Commodity purchases from affiliates		$ 674	$ 571	$ 555
Services provided by affiliates	[1]	453	454	422
Virginia Electric and Power Company | Affiliated Entity
Related Party Transaction [Line Items]
Services provided to related parties		25	22	22
Dominion Energy Gas Holdings, LLC
Related Party Transaction [Line Items]
Services provided to related parties	[2]	156	128	101
Commodity purchases from affiliates		5	9	10
Services provided by affiliates	[3]	143	141	133
Other receivables	[4]	12	10
Customer receivables from related parties		1	1
Affiliated notes receivable	[5]	20	18
Dominion Energy Gas Holdings, LLC | Affiliated Entity
Related Party Transaction [Line Items]
Services provided to related parties		70	69	$ 69
Imbalances receivable from affiliates		$ 1	2
Imbalances payable to affiliates	[6]		$ 4
[1]	Includes capitalized expenditures of $144 million, $144 million and $143 million for the year ended December 31, 2017, 2016 and 2015, respectively.
[2]	Amounts primarily attributable to Atlantic Coast Pipeline.
[3]	Includes capitalized expenditures of $45 million, $49 million and $57 million for the year ended December 31, 2017, 2016 and 2015, respectively.
[4]	Represents amounts due from Atlantic Coast Pipeline, a related party VIE.
[5]	Amounts are presented in other deferred charges and other assets in Dominion Energy Gas' Consolidated Balance Sheets.
[6]	Amounts are presented in other current liabilities in Dominion Energy Gas' Consolidated Balance Sheets.

Related-Party Transactions (Par

Related-Party Transactions (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Capital expenditures	$ 5,504	$ 6,085	$ 5,575
Virginia Electric and Power Company
Related Party Transaction [Line Items]
Capital expenditures	2,496	2,489	2,474
Virginia Electric and Power Company | Services provided by affiliates | Affiliated Entity
Related Party Transaction [Line Items]
Capital expenditures	144	144	143
Dominion Energy Gas Holdings, LLC
Related Party Transaction [Line Items]
Capital expenditures	778	854	795
Dominion Energy Gas Holdings, LLC | Services provided by affiliates | Affiliated Entity
Related Party Transaction [Line Items]
Capital expenditures	$ 45	$ 49	$ 57

Operating Segments (Narrative)

Operating Segments (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act	$ (851)		$ (851)
Charges associated with equity method investments in wind-powered generation facilities			158
Charges associated with equity method investments in wind-powered generation facilities, after tax	96
Charges associated with future ash pond and landfill closure costs				$ 197	$ 99
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act	(93)		(93)
Charges associated with future ash pond and landfill closure costs				197	99
Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act	$ (197)		(197)
Facilities Subject to Coal Combustion Residual Final Rule
Segment Reporting Information [Line Items]
Charge related to future ash pond and landfill closure costs		$ 122
Facilities Subject to Coal Combustion Residual Final Rule | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Charge related to future ash pond and landfill closure costs		$ 121
Operating Segments
Segment Reporting Information [Line Items]
After-tax net (expenses) benefit			861	(180)	(136)
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act			979
Charges associated with equity method investments in wind-powered generation facilities			158
Charges associated with equity method investments in wind-powered generation facilities, after tax			96
Operating Segments | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act			93
Operating Segments | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
After-tax net (expenses) benefit			(174)	(7)	(13)
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act			185
Ceiling test impairment charge					16
Ceiling test impairment charge, net of tax					10
Operating Segments | Organizational Design Initiative
Segment Reporting Information [Line Items]
Organizational design initiative charges, after tax				36
Organizational design initiative				59
Operating Segments | Organizational Design Initiative | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Organizational design initiative charges, after tax				5
Organizational design initiative				8
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
After-tax net (expenses) benefit			389	(484)	(391)
Operating Segments | Corporate and Other | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
After-tax net (expenses) benefit			74	(173)	(153)
Operating Segments | Corporate and Other | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
After-tax net (expenses) benefit			(179)	(3)	(21)
Operating Segments | Dominion Generation | Virginia Regulation | Deferred Fuel Costs
Segment Reporting Information [Line Items]
Write offs of deferred fuel costs					85
Write off of deferred fuel cost, net of tax					52
Operating Segments | Dominion Generation | Virginia Regulation | Deferred Fuel Costs | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Write offs of deferred fuel costs					85
Write off of deferred fuel cost, net of tax					52
Operating Segments | Dominion Generation | Facilities Subject to Coal Combustion Residual Final Rule
Segment Reporting Information [Line Items]
Charges associated with future ash pond and landfill closure costs				197	99
Charge related to future ash pond and landfill closure costs				122	60
Operating Segments | Dominion Generation | Facilities Subject to Coal Combustion Residual Final Rule | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Charges associated with future ash pond and landfill closure costs				197	99
Charge related to future ash pond and landfill closure costs				121	$ 60
Operating Segments | Gas Infrastructure | Organizational Design Initiative
Segment Reporting Information [Line Items]
Organizational design initiative charges, after tax			324	12
Operating Segments | Power Generation | Organizational Design Initiative
Segment Reporting Information [Line Items]
Organizational design initiative charges, after tax			$ 655	19
Operating Segments | Power Delivery | Organizational Design Initiative
Segment Reporting Information [Line Items]
Organizational design initiative charges, after tax				$ 5

Operating Segments (Schedule of

Operating Segments (Schedule of Segment Reporting Information, by Segment) (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenue	$ 3,210	$ 3,179	$ 2,813	$ 3,384	$ 3,086	$ 3,132	$ 2,598	$ 2,921	$ 12,586	[1]	$ 11,737	[1]	$ 11,683	[1]
Depreciation and amortization									1,905		1,559		1,395
Equity in earnings of equity method investees									(18)		111		56
Interest income									82		66		58
Interest and related charges									1,205		1,010		904
Income tax expense (benefit)									(30)		655		905
Net income	1,312	665	390	632	457	690	452	524	2,999		2,123		1,899
Investment in equity method investees	1,544				1,561				1,544		1,561		1,320
Capital expenditures									5,504		6,085		5,575
Capital expenditures									5,909		6,125		5,993
Total assets	76,585				71,610				76,585		71,610
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue	1,824	2,154	1,747	1,831	1,711	2,211	1,776	1,890	7,556		7,588		7,622
Depreciation and amortization									1,141		1,025		953
Interest income									19				7
Interest and related charges									494		461		443
Income tax expense (benefit)									774		727		659
Net income	407	459	318	356	172	503	280	263	1,540		1,218		1,087
Capital expenditures									2,496		2,489		2,474
Capital expenditures									2,729		2,649		2,689
Total assets	35,139				33,308				35,139		33,308
Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue	501	401	422	490	457	382	368	431	1,814	[2]	1,638	[2]	1,716	[2]
Depreciation and amortization									227		204		217
Equity in earnings of equity method investees									21		21		23
Interest income									2		1		1
Interest and related charges									97		94		73
Income tax expense (benefit)									51		215		283
Net income	313	$ 117	$ 77	$ 108	106	$ 83	$ 105	$ 98	615		392		457
Investment in equity method investees	95				98				95		98		102
Capital expenditures									778		854		795
Total assets	11,940				11,142				11,940		11,142
Power Delivery
Segment Reporting Information [Line Items]
Total revenue									2,206		2,210		2,091
Power Generation
Segment Reporting Information [Line Items]
Total revenue									6,676		6,747		7,001
Gas Infrastructure
Segment Reporting Information [Line Items]
Total revenue									2,832		2,069		1,877
Gas Infrastructure | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue									1,814		1,638		1,716
Depreciation and amortization									227		214		213
Equity in earnings of equity method investees									21		21		23
Interest income									2		1		1
Interest and related charges									97		92		72
Income tax expense (benefit)									256		237		296
Net income									436		395		478
Investment in equity method investees	95				98				95		98		102
Capital expenditures									778		854		795
Total assets	11,300				10,500				11,300		10,500
Corporate and Other
Segment Reporting Information [Line Items]
Total revenue									16		(7)		(27)
Corporate and Other | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Depreciation and amortization											(10)		4
Interest and related charges											2		1
Income tax expense (benefit)									(205)		(22)		(13)
Net income									179		(3)		(21)
Total assets	600				600				600		600
Adjustments & Eliminations
Segment Reporting Information [Line Items]
Total revenue									856		718		741
Interest income									(155)		(78)		(44)
Interest and related charges									(155)		(78)		(44)
Total assets	(9,100)				(7,300)				(9,100)		(7,300)
Adjustments & Eliminations | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Interest income									(3)
Interest and related charges									(3)		(2)		(1)
Total assets	(100)				(100)				(100)		(100)
Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue									(1,476)		(1,339)		(1,284)
Intersegment revenue | Power Delivery
Segment Reporting Information [Line Items]
Total revenue									(22)		(23)		(20)
Intersegment revenue | Power Generation
Segment Reporting Information [Line Items]
Total revenue									(10)		(10)		(15)
Intersegment revenue | Gas Infrastructure
Segment Reporting Information [Line Items]
Total revenue									(834)		(697)		(695)
Intersegment revenue | Corporate and Other
Segment Reporting Information [Line Items]
Total revenue									(610)		(609)		(554)
Eliminations
Segment Reporting Information [Line Items]
Total revenue									(620)		(621)		(543)
Operating Segments
Segment Reporting Information [Line Items]
Total revenue									12,586		11,737		11,683
Operating Segments | Power Delivery
Segment Reporting Information [Line Items]
Total revenue									2,228		2,233		2,111
Depreciation and amortization									593		537		498
Interest income									4
Interest and related charges									265		244		230
Income tax expense (benefit)									334		308		307
Net income									531		484		490
Capital expenditures									1,433		1,320		1,607
Total assets	16,700				15,600				16,700		15,600
Operating Segments | Power Delivery | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue									2,212		2,217		2,099
Depreciation and amortization									594		537		498
Interest income									4
Interest and related charges									265		244		230
Income tax expense (benefit)									334		307		308
Net income									527		482		490
Capital expenditures									1,439		1,313		1,569
Total assets	16,600				15,600				16,600		15,600
Operating Segments | Power Generation
Segment Reporting Information [Line Items]
Total revenue									6,686		6,757		7,016
Depreciation and amortization									747		662		591
Equity in earnings of equity method investees									(181)		(16)		(15)
Interest income									92		74		64
Interest and related charges									342		290		262
Income tax expense (benefit)									373		279		465
Net income									1,181		1,397		1,120
Investment in equity method investees	81				228				81		228		245
Capital expenditures									2,275		2,440		2,190
Total assets	29,000				27,100				29,000		27,100
Operating Segments | Power Generation | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue									5,344		5,390		5,566
Depreciation and amortization									547		488		453
Interest income									15				7
Interest and related charges									232		219		210
Income tax expense (benefit)									534		524		437
Net income									939		909		750
Capital expenditures									1,290		1,336		1,120
Total assets	18,600				17,800				18,600		17,800
Operating Segments | Gas Infrastructure
Segment Reporting Information [Line Items]
Total revenue									3,666		2,766		2,572
Depreciation and amortization									522		330		262
Equity in earnings of equity method investees									159		105		60
Interest income									45		34		25
Interest and related charges									109		38		27
Income tax expense (benefit)									487		431		423
Net income									898		726		680
Investment in equity method investees	1,422				1,289				1,422		1,289		1,042
Capital expenditures									2,149		2,322		2,153
Total assets	28,000				26,000				28,000		26,000
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
Total revenue									626		602		527
Depreciation and amortization									43		30		44
Equity in earnings of equity method investees									4		22		11
Interest income									96		36		13
Interest and related charges									644		516		429
Income tax expense (benefit)									(1,224)		(363)		(290)
Net income									389		(484)		(391)
Investment in equity method investees	41				44				41		44		33
Capital expenditures									52		43		43
Total assets	$ 12,000				$ 10,200				12,000		10,200
Operating Segments | Corporate and Other | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue											(19)		(43)
Depreciation and amortization													2
Interest income									3
Interest and related charges													4
Income tax expense (benefit)									(94)		(104)		(86)
Net income									$ 74		$ (173)		$ (153)
[1]	See Note 9 for amounts attributable to related parties.
[2]	See Note 24 for amounts attributable to related parties.

Quarterly Financial and Common

Quarterly Financial and Common Stock Data (Unaudited) (Quarterly Financial and Common Stock Data) (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Operating Revenue	$ 3,210	$ 3,179	$ 2,813	$ 3,384	$ 3,086	$ 3,132	$ 2,598	$ 2,921	$ 12,586	[1]	$ 11,737	[1]	$ 11,683	[1]
Income from operations	953	1,152	753	1,079	765	1,102	740	841	3,937		3,448		3,420
Net income including noncontrolling interests	1,333	696	417	674	491	728	462	531	3,120		2,212		1,923
Net income (loss) attributable to Dominion Energy	$ 1,312	$ 665	$ 390	$ 632	$ 457	$ 690	$ 452	$ 524	$ 2,999		$ 2,123		$ 1,899
Net income attributable to Dominion Energy - Basic	$ 2.04	$ 1.03	$ 0.62	$ 1.01	$ 0.73	$ 1.10	$ 0.73	$ 0.88	$ 4.72		$ 3.44		$ 3.21
Net income attributable to Dominion Energy - Diluted	2.04	1.03	0.62	1.01	0.73	1.10	0.73	0.88	4.72		3.44		3.20
Dividends declared per share	$ 0.770	$ 0.770	$ 0.755	$ 0.755	$ 0.700	$ 0.700	$ 0.700	$ 0.700	$ 3.035		$ 2.800		$ 2.590
Virginia Electric and Power Company
Condensed Financial Statements, Captions [Line Items]
Operating Revenue	$ 1,824	$ 2,154	$ 1,747	$ 1,831	$ 1,711	$ 2,211	$ 1,776	$ 1,890	$ 7,556		$ 7,588		$ 7,622
Income from operations	619	847	613	653	369	914	553	514	2,732		2,350		2,121
Net income (loss) attributable to Dominion Energy	407	459	318	356	172	503	280	263	1,540		1,218		1,087
Dominion Energy Gas Holdings, LLC
Condensed Financial Statements, Captions [Line Items]
Operating Revenue	501	401	422	490	457	382	368	431	1,814	[2]	1,638	[2]	1,716	[2]
Income from operations	181	185	116	156	156	114	167	156	638		593		727
Net income (loss) attributable to Dominion Energy	$ 313	$ 117	$ 77	$ 108	$ 106	$ 83	$ 105	$ 98	$ 615		$ 392		$ 457
Maximum
Condensed Financial Statements, Captions [Line Items]
Share Price (in dollars per share)	$ 85.30	$ 80.67	$ 81.65	$ 79.36	$ 77.32	$ 78.97	$ 77.93	$ 75.18
Minimum
Condensed Financial Statements, Captions [Line Items]
Share Price (in dollars per share)	$ 75.75	$ 75.40	$ 76.17	$ 70.87	$ 69.51	$ 72.49	$ 68.71	$ 66.25
[1]	See Note 9 for amounts attributable to related parties.
[2]	See Note 24 for amounts attributable to related parties.

Quarterly Financial and Comm167

Quarterly Financial and Common Stock Data (Unaudited) (Narrative) (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
Parent Company Only Financial Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act	$ (851)		$ (851)
Charges associated with equity method investments in wind-powered generation facilities, after tax	96
Virginia Electric and Power Company
Parent Company Only Financial Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act	(93)		(93)
Dominion Energy Gas Holdings, LLC
Parent Company Only Financial Information [Line Items]
Tax benefit resulting from remeasurement of deferred income taxes as a result of the 2017 Tax Reform Act	$ (197)		$ (197)
Facilities Subject to Coal Combustion Residual Final Rule
Parent Company Only Financial Information [Line Items]
Charge related to future ash pond and landfill closure costs		$ 122
Facilities Subject to Coal Combustion Residual Final Rule | Virginia Electric and Power Company
Parent Company Only Financial Information [Line Items]
Charge related to future ash pond and landfill closure costs		$ 121