Acquisitions, Development and Divestitures - Development (Details) $ in Millions			3 Months Ended			6 Months Ended	9 Months Ended			12 Months Ended
		Nov. 06, 2023 MW	Sep. 30, 2024 USD ($)		Sep. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2024 USD ($)		Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Business Acquisition [Line Items]
Transition Service Agreement Cost			$ 32		$ 59		$ 129		$ 179
Goodwill			2,247				2,247			$ 2,247
Operating Revenues from external customers			2,066		2,043		6,251		6,281
Net income (loss)			214		230		711		627
Indemnification for Safari sale/leaseback							25
Louisville Gas And Electric Co [Member]
Business Acquisition [Line Items]
Goodwill			389				389			389
Operating Revenues from external customers			397		398		1,239		1,227
Net income (loss)			77	[1]	79		232	[1]	210
New NGCC LG&E Planned Ownership Percentage		31.00%
CPCN NGCC Combustion Turbine Facilities Power | MW		640
Kentucky Utilities Co [Member]
Business Acquisition [Line Items]
Goodwill			607				607			607
Operating Revenues from external customers			509		505		1,498		1,439
Net income (loss)	[2]		98		101		283		240
New NGCC KU Planned Ownership Percentage		69.00%
CPCN NGCC Combustion Turbine Facilities Power | MW		640
Narragansett Electric
Business Acquisition [Line Items]
Total cash consideration						$ 3,800
Rhode Island Regulated
Business Acquisition [Line Items]
Operating Revenues from external customers			455		413		1,393		1,355	$ 1,400
Net income (loss)			14		6		90		70
Corporate and Other [Member]
Business Acquisition [Line Items]
Operating Revenues from external customers			0		0		1		0
Net income (loss)			(111)		(87)		(313)		(259)
Rhode Island Energy | Rhode Island Energy TSA
Business Acquisition [Line Items]
Other Nonrecurring (Income) Expense			85		69		250		193
Rhode Island Energy | Accrual for TSA Markup
Business Acquisition [Line Items]
Other Nonrecurring (Income) Expense			5		$ 2		8		$ 6
LGE [Member]
Business Acquisition [Line Items]
CPCN NGCC Combustion Turbine Facilities Power | MW		640
KU [Member]
Business Acquisition [Line Items]
CPCN NGCC Combustion Turbine Facilities Power | MW		640
LKE [Member]
Business Acquisition [Line Items]
ExpectedCapitalCostOfExpansionProject			$ 1,000				$ 1,000

[1] Net income equals comprehensive income.

[2] Net income equals comprehensive income.