Summary of Significant Accounting Policies and Other Matters - Narrative (Details) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2016 mi	Mar. 31, 2024 USD ($) project shares	Mar. 31, 2023 USD ($) dealer $ / shares shares	Dec. 31, 2019 USD ($)	Apr. 30, 2024 USD ($)	Dec. 31, 2023	Mar. 01, 2023 project	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Antidilutive shares (in shares) | shares		0	1,900,000
Number of dealers | dealer			2
Par value of common stock (in usd per share) | $ / shares			$ 0.10
Authorized repurchased amount			$ 1,000
Disposal Group, Held-for-sale, Not Discontinued Operations | Clean Energy Businesses
Schedule of Equity Method Investments [Line Items]
Tax equity projects | project		3					2
Mountain Valley Pipeline LLC | Con Edison Gas Pipeline and Storage, LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage (in percent)		7.20%				7.90%		9.60%
Number of miles in pipeline construction | mi	300
Cash contributions for equity method investments		$ 530		$ 530
Equity method investment, ownership percentage, expected percentage		0.0675
Equity method investment, project percent completion (in percent)		99.00%				97.00%
Equity method investments		$ 153
Mountain Valley Pipeline LLC | Con Edison Gas Pipeline and Storage, LLC | Subsequent Event
Schedule of Equity Method Investments [Line Items]
Aggregate project cost					$ 7,850
Mountain Valley Pipeline LLC | Con Edison Gas Pipeline and Storage, LLC | Mountain Valley Pipeline LLC
Schedule of Equity Method Investments [Line Items]
Ownership percentage (in percent)	12.50%
Broken Bow II | Clean Energy Businesses | Electric Energy (MWh)
Schedule of Equity Method Investments [Line Items]
Deferred projects | project		1					1