Operating Segments (Schedule of Segment Reporting Information, by Segment) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Total revenue from external customers		$ 3,179	$ 3,132	$ 9,376	$ 8,651
Net income (loss) attributable to Dominion Energy		665	690	1,687	1,666
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers	[1]	2,154	2,211	5,732	5,877
Net income (loss) attributable to Dominion Energy		459	503	1,133	1,046
Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue from external customers	[2]	401	382	1,313	1,181
Net income (loss) attributable to Dominion Energy		117	83	302	286
Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		(361)	(357)	(1,120)	(1,000)
Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		3,179	3,132	9,376	8,651
Adjustments/Eliminations
Segment Reporting Information [Line Items]
Total revenue from external customers		206	210	660	522
Net income (loss) attributable to Dominion Energy		0		0	0
Eliminations
Segment Reporting Information [Line Items]
Total revenue from external customers		(155)	(147)	(460)	(478)
Power Delivery
Segment Reporting Information [Line Items]
Total revenue from external customers		580	614	1,664	1,682
Net income (loss) attributable to Dominion Energy		138	139	390	363
Power Delivery | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		4	6	16	17
Power Delivery | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		584	620	1,680	1,699
Power Delivery | Operating Segments | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers		580	617	1,670	1,686
Net income (loss) attributable to Dominion Energy		137	140	387	362
Power Generation
Segment Reporting Information [Line Items]
Total revenue from external customers		1,931	1,947	5,091	5,204
Net income (loss) attributable to Dominion Energy		369	650	870	1,066
Power Generation | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		3	2	8	7
Power Generation | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		1,934	1,949	5,099	5,211
Power Generation | Operating Segments | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers		1,574	1,594	4,062	4,191
Net income (loss) attributable to Dominion Energy		314	359	735	699
Gas Infrastructure
Segment Reporting Information [Line Items]
Total revenue from external customers		459	359	1,949	1,235
Net income (loss) attributable to Dominion Energy		187	135	613	483
Gas Infrastructure | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		204	205	645	507
Gas Infrastructure | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		663	564	2,594	1,742
Gas Infrastructure | Operating Segments | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue from external customers		401	382	1,313	1,181
Net income (loss) attributable to Dominion Energy		121	77	318	288
Corporate and Other
Segment Reporting Information [Line Items]
Total revenue from external customers		3	2	12	8
Net income (loss) attributable to Dominion Energy		(29)	(234)	(186)	(246)
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		150	144	451	469
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		153	146	463	477
Corporate and Other | Operating Segments | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers		0	0	0	0
Net income (loss) attributable to Dominion Energy		8	4	11	(15)
Corporate and Other | Operating Segments | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue from external customers		0	0	0	0
Net income (loss) attributable to Dominion Energy		$ (4)	$ 6	$ (16)	$ (2)

[1] See Note 17 for amounts attributable to affiliates.

[2] See Note 17 for amounts attributable to related parties.