Business Combination Disclosure Business Combination Disclosure (Details) $ in Millions				3 Months Ended		10 Months Ended	12 Months Ended
	Nov. 02, 2020 USD ($)	Nov. 01, 2020 USD ($) mi Bcf	Oct. 29, 2020 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Oct. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Jul. 03, 2020 USD ($)
Business Acquisition [Line Items]
Preferred Stock, Value, Issued				$ 3,750				$ 3,750
Operating revenue				6,081	$ 4,527
Net Income (Loss) Attributable to Parent				4	670
Goodwill				11,534				$ 11,506
Deferred income taxes and amortization of investment tax credits				(135)	47
Natural Gas Transmission and Storage Business Acquisition [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		$ 2,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt		4,415							$ 5,600
Preferred Stock, Value, Issued			$ 3,750
Preferred Stock, Dividend Rate, Percentage			4.00%
Net Income (Loss) Attributable to Parent				$ 107
Business Acquisition, Accounting Revision Period, Twelve Months				12 months
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets		569
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		9,254
Goodwill		1,732
Regulatory Assets		108
Deferred income taxes and amortization of investment tax credits						$ 275
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		1,424
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		13,362
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities		1,567
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Regulatory Liabilities		661
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other		289
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities		6,932
Noncontrolling Interest, Increase from Business Combination						$ 3,916
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		2,514
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		104
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt		1,200
Business Acquisition, Pro Forma Revenue					5,056
Business Acquisition, Pro Forma Net Income (Loss)					$ 773
Natural Gas Transmission and Storage Business Acquisition [Member] | Goodwill
Business Acquisition [Line Items]
Finite-Lived Intangible Asset, Useful Life				15 years
Natural Gas Transmission and Storage Business Acquisition [Member] | Domestic Tax Authority and State and Local Jurisdiction
Business Acquisition [Line Items]
Goodwill		$ 900
Natural Gas Transmission and Storage Business Acquisition [Member] | Natural Gas
Business Acquisition [Line Items]
Operating revenue				$ 559
Natural Gas Transmission and Storage Business Acquisition [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Cove Point LNG, LP [Member] | Other Ownership Interest
Business Acquisition [Line Items]
Variable interest entity, ownership percentage		25.00%
Natural Gas Transmission and Storage Business Acquisition [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Cove Point LNG, LP [Member] | General Partner [Member]
Business Acquisition [Line Items]
Variable interest entity, ownership percentage		100.00%
Natural Gas Transmission and Storage Business Acquisition [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Cove Point LNG, LP [Member] | Limited Partner [Member]
Business Acquisition [Line Items]
Variable interest entity, ownership percentage		25.00%
Natural Gas Transmission and Storage Business Acquisition [Member] | Iroquois Gas Transmission System L.P. [Member]
Business Acquisition [Line Items]
Equity method investment, ownership percentage		50.00%
Natural Gas Transmission and Storage Business Acquisition [Member] | Eastern Gas Transmission, Inc. [Member]
Business Acquisition [Line Items]
Ownership Percentage Acquired		100.00%
Natural Gas Transmission and Storage Business Acquisition [Member] | Carolina Gas Transmission, LLC [Member]
Business Acquisition [Line Items]
Ownership Percentage Acquired		100.00%
Questar Pipeline Group and Dominion Questar Transaction [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 1,300
Questar Pipeline Group and Dominion Questar Transaction [Member] | Forecast [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross							$ 1,300
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt							$ 430
Natural Gas Transmission and Storage Transaction [Member]
Business Acquisition [Line Items]
Miles of natural gas transmission lines | mi		5,400
Natural gas transmission lines transportation per day capacity | Bcf		12.5
Natural gas operated storage capacity | Bcf		420
Natural gas company-owned working storage capacity | Bcf		306
Liquefied natural gas storage capacity | Bcf		14.6