Property, Plant and Equipment (Property, Plant and Equipment) (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Utility:
Generation	$ 19,250	$ 17,602
Transmission	16,669	15,335
Distribution	18,549	17,408
Storage	2,905	2,887
Nuclear fuel	1,626	1,599
Gas gathering and processing	307	219
Oil and gas	1,763	1,720
General and other	1,476	1,514
Plant under construction	2,385	7,765
Total utility	64,930	66,049
Nonutility:
Merchant generation-nuclear	1,550	1,452
Merchant generation-other	3,802	4,992
Nuclear fuel	1,025	968
Gas gathering and processing	185	630
LNG facility	3,977
Other-including plant under construction	1,109	732
Total nonutility	11,648	8,774
Total property, plant and equipment	76,578	74,823
Virginia Electric and Power Company
Utility:
Generation	19,250	17,602
Transmission	9,392	8,332
Distribution	11,785	11,151
Nuclear fuel	1,626	1,599
General and other	821	794
Plant under construction	1,639	2,840
Total utility	44,513	42,318
Nonutility:
Other-including plant under construction	11	11
Total property, plant and equipment	44,524	42,329
Dominion Energy Gas Holdings, LLC
Utility:
Transmission	4,758	4,732
Distribution	3,527	3,267
Storage	1,691	1,688
Gas gathering and processing	210	202
General and other	233	216
Plant under construction	494	293
Total utility	10,913	10,398
Nonutility:
Gas gathering and processing	185	630
Other-including plant under construction	140	145
Total nonutility	325	775
Total property, plant and equipment	$ 11,238	$ 11,173