Property, Plant and Equipment, Net - EEGH (Details) - Eastern Energy Gas Holdings, LLC [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Public Utility, Property, Plant and Equipment [Line Items]
Plant, net	$ 9,934	$ 11,008
Construction work- in-progress	210	719
Property, plant and equipment, net	10,144	11,727
Regulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Plant in service, net	8,497	10,168
Accumulated depreciation and amortization	(2,759)	(3,414)
Plant, net	5,738	6,754
Construction work- in-progress	196	584
Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Plant in service, net	4,479	4,450
Accumulated depreciation and amortization	(283)	(196)
Plant, net	$ 4,196	4,254
Interstate natural gas pipeline assets [Member] | Minimum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciable life	24 years
Interstate natural gas pipeline assets [Member] | Maximum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciable life	43 years
Interstate natural gas pipeline assets [Member] | Regulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Plant in service, net	$ 8,382	10,025
Other Intangible Assets [Member] | Minimum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciable life	5 years
Other Intangible Assets [Member] | Maximum [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciable life	10 years
Other Intangible Assets [Member] | Regulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Plant in service, net	$ 115	143
Other Intangible Assets [Member] | Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciable life	14 years
Plant in service, net	$ 25	25
LNG Facility [Member] | Nonregulated Operation [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciable life	40 years
Plant in service, net	$ 4,454	$ 4,425