Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Noncontrolling Interest [Member]	Long-term income tax receivable [Member]	PacifiCorp [Member]	PacifiCorp [Member] Preferred Stock [Member]	PacifiCorp [Member] Common Stock [Member]	PacifiCorp [Member] Additional Paid-in Capital [Member]	PacifiCorp [Member] Retained Earnings [Member]	PacifiCorp [Member] Accumulated Other Comprehensive Income (Loss) [Member]	MidAmerican Energy Company [Member]	MidAmerican Energy Company [Member] Common Stock [Member]	MidAmerican Energy Company [Member] Additional Paid-in Capital [Member]	MidAmerican Energy Company [Member] Retained Earnings [Member]	MidAmerican Funding, LLC and Subsidiaries [Member]	MidAmerican Funding, LLC and Subsidiaries [Member] Additional Paid-in Capital [Member]	MidAmerican Funding, LLC and Subsidiaries [Member] Retained Earnings [Member]	Nevada Power Company [Member]	Nevada Power Company [Member] Common Stock [Member]	Nevada Power Company [Member] Additional Paid-in Capital [Member]	Nevada Power Company [Member] Retained Earnings [Member]	Nevada Power Company [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Sierra Pacific Power Company [Member]	Sierra Pacific Power Company [Member] Common Stock [Member]	Sierra Pacific Power Company [Member] Additional Paid-in Capital [Member]	Sierra Pacific Power Company [Member] Retained Earnings [Member]	Sierra Pacific Power Company [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Eastern Energy Gas Holdings, LLC [Member]	Eastern Energy Gas Holdings, LLC [Member] Dominion Energy Questar Pipeline Services, Inc. [Member]	Eastern Energy Gas Holdings, LLC [Member] Cove Point LNG, LP [Member]	Eastern Energy Gas Holdings, LLC [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Eastern Energy Gas Holdings, LLC [Member] Noncontrolling Interest [Member]	Eastern Energy Gas Holdings, LLC [Member] Noncontrolling Interest [Member] Cove Point LNG, LP [Member]	Eastern Energy Gas Holdings, LLC [Member] Member Units [Member]	Eastern Energy Gas Holdings, LLC [Member] Member Units [Member] Dominion Energy Questar Pipeline Services, Inc. [Member]	Eastern Energy Gas Holdings, LLC [Member] Member Units [Member] Cove Point LNG, LP [Member]	Eastern Energy Gas Holdings, LLC [Member] Predecessor Equity [Member]
Balance (shares) at Dec. 31, 2017																								1,000					1,000
Balance at Dec. 31, 2017					$ 1,085		$ (1,085)			$ 7,555	$ 2	$ 0	$ 4,479	$ 3,089	$ (15)	$ 5,764	$ 0	$ 561	$ 5,203	$ 6,660	$ 1,679	$ 4,981	$ 2,678	$ 0	$ 2,308	$ 374	$ (4)	$ 1,172	$ 0	$ 1,111	$ 62	$ (1)				$ (98)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 2,588	$ 0	$ 0	$ 2,568		$ 0		$ 20
Net income (loss) attributable to parent	2,568									738			0	738	0	682			682	669		669	226			226		92			92		$ 481
Other comprehensive income (loss)	(462)	0	0	0		(462)		0		2			0	0	2																		(45)			(45)
Noncontrolling Interest, Increase from Sale of Parent Equity Interest																																	4				$ 4
Contributions																																	48									$ 48
Distributions																																	(296)				(138)		$ (25)			(133)
Remeasurement of noncontrolling interest in Northeast Midstream																																	0				(375)					375
Reclassification of long-term income tax receivable	609								$ 609
Long-term income tax receivable adjustments	(17)		0	(135)					(152)
Distributions	(23)	0	0	0		0		(23)	0																								0				27					(27)
Common stock dividends declared										(450)			0	(450)	0
Common stock, value, repurchased	(107)	0	(6)	(101)		0		0	0
Other equity transactions	11	0	9	1		0		1	0																						(1)	1
Balance (shares) at Dec. 31, 2018																								1,000					1,000
Balance at Dec. 31, 2018	29,723		6,371	25,624		(1,945)		130																									8,865			(169)	2,664		4,566			1,804
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,591																																656				175		301			180
Balance at Dec. 31, 2018										7,845	2	0	4,479	3,377	(13)	6,446	$ 0	561	5,885	7,329	1,679	5,650	2,904	$ 0	2,308	600	(4)	1,264	$ 0	1,111	153	0				(169)
Long-term income tax receivable									457
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,968	0	0	2,950		0		18
Net income (loss) attributable to parent	2,950									771			0	771	0	793			793	781		781	264			264		103			103		721
Other comprehensive income (loss)	239	0	0	0		239		0		(4)			0	(1)	(3)																		(18)			(17)	(1)
Contributions																																	3,385									3,385
Distribution to parent																				(8)		(8)
Long-term income tax receivable adjustments	(40)		(33)	0					(73)
Distributions	(22)	0	0	0		0		(22)	0																								(636)				(179)					(457)
Acquisition of public interest in Northeast Midstream																																	(40)				(1,221)					1,181
Dominion Energy Gas Restructuring																																	(2,168)			(1)			3,978			(6,145)
Common stock dividends declared										$ (175)			0	(175)	0								$ (371)			(371)		(46)			(46)
Common stock, value, repurchased	(293)	0	(15)	(278)		0		0	0
Other equity transactions	$ 3	0	0	0		0		3	0							1			1	(1)		(1)						$ (1)				(1)	(1)				1		(2)
Balance (shares) at Dec. 31, 2019	77,000,000									357,000,000							71,000,000						1,000	1,000				1,000	1,000
Balance at Dec. 31, 2019	$ 32,578		6,389	28,296		(1,706)		129																									10,229			(187)	1,385		9,031			0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,968																																842				121		489			$ 232
Balance at Dec. 31, 2019	32,449									$ 8,437	2	0	4,479	3,972	(16)	7,240	$ 0	561	6,679	8,101	1,679	6,422	$ 2,797	$ 0	2,308	493	(4)	$ 1,320	$ 0	1,111	210	(1)				(187)
Long-term income tax receivable	530								530
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,013	0	0	6,943		0		70
Net income (loss) attributable to parent	6,943									739			0	739	0	826			826	818		818	295			295		111			111		109
Other comprehensive income (loss)	153	0	0	0		153		0		$ (3)			0	0	(3)																		124			134	(10)
Noncontrolling Interest, Increase from Sale of Parent Equity Interest																																			$ 0			$ 2,765			$ (2,765)
Contributions																																	1,223						1,223
Long-term income tax receivable adjustments	(128)		0	0					(128)
Distributions	(121)	0	0	0		0		(121)	0																								(4,498)				(216)		(4,282)
Stockholders' Equity, Distribution Of Net Assets Of Subsidiary To Affiliate																																		$ 699						$ 699
Acquisition of public interest in Northeast Midstream	(33)		(5)					28																									(343)						(343)
Common stock dividends declared																							(155)			(155)		$ (20)			(20)
Common stock, value, repurchased	(126)	0	(6)	(120)		0		0	0
Other equity transactions	$ 1	$ 0	(1)	0		1		1	0							(1)			(1)				$ 2			1	1						0				3		(3)
Balance (shares) at Dec. 31, 2020	76,000,000									357,000,000							71,000,000						1,000	1,000				1,000	1,000
Balance at Dec. 31, 2020	$ 46,977		$ 6,377	$ 35,093		$ (1,552)		$ 3,967																									6,995			(53)	4,091		2,957
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,014																																$ 273				$ 164		$ 109
Balance at Dec. 31, 2020	43,010									$ 9,173	$ 2	$ 0	$ 4,479	$ 4,711	$ (19)	$ 8,065	$ 0	$ 561	$ 7,504	$ 8,919	$ 1,679	$ 7,240	$ 2,939	$ 0	$ 2,308	$ 634	$ (3)	$ 1,411	$ 0	$ 1,111	$ 301	$ (1)				$ (53)
Long-term income tax receivable	$ 658								$ 658