Regulatory Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Assets	$ 265	$ 237
Total Non Current Regulatory Assets	$ 698	724
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	3 years
Total regulatory assets	$ 963	961
Total Current Regulatory Liabilities	$ 41	64
Remaining Recovery Period of Regulatory Liabilities	1 year
Total Non Current Regulatory Liabilities	$ 709	813
Total regulatory liabilities	750	877
Overcollection of Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Liabilities	34	46
Deferred Income Tax Charge [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Liabilities	117	134
Asset Retirement Obligation Costs
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Liabilities	586	657
Other Regulatory Liabilities
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Liabilities	7	18
Total Non Current Regulatory Liabilities	6	22
El Salvador Tariff Recoveries
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Assets	119	78
Pension Costs
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Assets	179	194
Deferred Midwest Independent Service Operator Costs
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Assets	21	34
Environmental Restoration Costs [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Assets	70	73
Other Regulatory Assets
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Assets	19	14
Total Non Current Regulatory Assets	123	130
Petersburg Unit Retirement Costs
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Assets	260	287
Deferred Fuel and Purchase Power Costs
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Non Current Regulatory Assets	45	6
Deferred fuel and purchased power costs (Current)
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Assets	0	80
Uncollection of rate riders
Schedule of Regulatory Assets and Liabilities [Line Items]
Total Current Regulatory Assets	$ 127	$ 65