Summary of Significant Accounting Policies and Other Matters - Investments (Details) - Mountain Valley Pipeline $ in Millions	1 Months Ended	12 Months Ended
	Jun. 30, 2024 mi	Dec. 31, 2024 USD ($)	Dec. 31, 2016 mi	Dec. 31, 2023 USD ($)	Dec. 31, 2021 USD ($)	May 31, 2021 USD ($)	Dec. 31, 2019 USD ($)	Jan. 31, 2016
Schedule of Equity Method Investments [Line Items]
Equity method investments		$ 530		$ 530
CET Gas
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percent (in percent)		6.70%
Number of miles in pipeline construction | mi	303		300
Equity method investments					$ 166		$ 530
Aggregate project cost		$ 8,100				$ 8,100
Payments to acquire equity method investments		530
Income (loss) from equity method investments		29
Income (loss) from equity method Investments, after tax		$ 21
Expected reduction in equity interest		6.60%
CET Gas | Mountain Valley Pipeline
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percent (in percent)								12.50%