Operating Segments (Schedule of Segment Reporting Information, by Segment) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Total revenue from external customers		$ 2,813	$ 2,598	$ 6,197	$ 5,519
Net income (loss) attributable to Dominion Energy		390	452	1,022	976
Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers	[1]	1,747	1,776	3,578	3,666
Net income (loss) attributable to Dominion Energy		318	280	674	543
Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue from external customers	[2]	422	368	912	799
Net income (loss) attributable to Dominion Energy		77	105	185	203
Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		(333)	(265)	(759)	(643)
Adjustments/Eliminations
Segment Reporting Information [Line Items]
Total revenue from external customers		181	128	454	312
Net income (loss) attributable to Dominion Energy		0	0	0	0
Eliminations
Segment Reporting Information [Line Items]
Total revenue from external customers		(152)	(137)	(305)	(331)
Power Delivery
Segment Reporting Information [Line Items]
Total revenue from external customers		537	518	1,096	1,079
Power Delivery | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		530	512	1,084	1,068
Net income (loss) attributable to Dominion Energy		127	104	252	224
Power Delivery | Operating Segments | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers		533	512	1,090	1,069
Net income (loss) attributable to Dominion Energy		125	104	250	222
Power Delivery | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		7	6	12	11
Power Generation
Segment Reporting Information [Line Items]
Total revenue from external customers		1,509	1,566	3,165	3,262
Power Generation | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		1,507	1,564	3,160	3,257
Net income (loss) attributable to Dominion Energy		240	171	501	416
Power Generation | Operating Segments | Virginia Electric and Power Company
Segment Reporting Information [Line Items]
Total revenue from external customers		1,214	1,264	2,488	2,597
Net income (loss) attributable to Dominion Energy		198	174	421	340
Power Generation | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		2	2	5	5
Gas Infrastructure
Segment Reporting Information [Line Items]
Total revenue from external customers		764	515	1,931	1,178
Gas Infrastructure | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		589	391	1,490	876
Net income (loss) attributable to Dominion Energy		163	162	426	348
Gas Infrastructure | Operating Segments | Dominion Energy Gas Holdings, LLC
Segment Reporting Information [Line Items]
Total revenue from external customers		422	368	912	799
Net income (loss) attributable to Dominion Energy		88	108	197	211
Gas Infrastructure | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		175	124	441	302
Corporate and Other
Segment Reporting Information [Line Items]
Total revenue from external customers		155	136	310	331
Corporate and Other | Operating Segments
Segment Reporting Information [Line Items]
Total revenue from external customers		6	3	9	6
Net income (loss) attributable to Dominion Energy		(140)	15	(157)	(12)
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		(5)	2	3	(19)
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		(11)	(3)	(12)	(8)
Corporate and Other | Intersegment revenue
Segment Reporting Information [Line Items]
Total revenue from external customers		$ 149	$ 133	$ 301	$ 325

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

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