Leases - Lessee (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Lease, Cost [Abstract]
Operating lease cost	$ 0	$ 26	$ 20
Short-term lease cost	0	6	6
Total lease cost	0	33	26
Operating cash flows from operating leases	0	25	26
Right-of-use asset obtained in exchange for new operating lease liabilities	0	47	15
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022	0
2023	0
2024	0
2025	0
2026	0
Thereafter	0
Total	$ 0
Assets and Liabilities, Lessee [Abstract]
Weighted-average discount rate
Weighted-average remaining lease term (in years)
Current lease liabilities	$ 0
Non-current lease liabilities	0
Right-of-use assets	$ 0
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other deferred credits and noncurrent liabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other noncurrent assets
Finance Lease, Right-of-Use Asset, Amortization	$ 0	1	0
Finance Lease, Interest Expense	0	0	0
Finance Lease, Interest Payment on Liability	0	0	0
Finance Lease, Principal Payments	0	1	0
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	0	7	0
Finance Lease, Liability, to be Paid, Year One	0
Finance Lease, Liability, to be Paid, Year Two	0
Finance Lease, Liability, to be Paid, Year Three	0
Finance Lease, Liability, to be Paid, Year Four	0
Finance Lease, Liability, to be Paid, Year Five	0
Finance Lease, Liability, to be Paid, after Year Five	0
Finance Lease, Liability, to be Paid	$ 0
Finance Lease, Weighted Average Discount Rate, Percent
Finance Lease, Weighted Average Remaining Lease Term
Finance Lease, Liability, Current	$ 0
Finance Lease, Liability, Noncurrent	0
Finance Lease, Right-of-Use Asset, before Accumulated Amortization	$ 0
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Regulated utility plant
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other deferred credits and noncurrent liabilities
Louisville Gas And Electric Co [Member]
Lease, Cost [Abstract]
Operating lease cost		5	6
Short-term lease cost		1	1
Total lease cost	0	6	7
Operating cash flows from operating leases		6	8
Right-of-use asset obtained in exchange for new operating lease liabilities		6	4
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022
2023
2024
2025
2026
Thereafter
Total	$ 0
Assets and Liabilities, Lessee [Abstract]
Weighted-average discount rate
Weighted-average remaining lease term (in years)
Current lease liabilities
Non-current lease liabilities
Right-of-use assets
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other deferred credits and noncurrent liabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other noncurrent assets
Louisville Gas And Electric Co [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	1 year
Louisville Gas And Electric Co [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	10 years
Kentucky Utilities Co [Member]
Lease, Cost [Abstract]
Operating lease cost		10	9
Short-term lease cost		1	2
Total lease cost	0	11	11
Operating cash flows from operating leases		9	12
Right-of-use asset obtained in exchange for new operating lease liabilities		$ 10	$ 5
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2022
2023
2024
2025
2026
Thereafter
Total	$ 0
Assets and Liabilities, Lessee [Abstract]
Weighted-average discount rate
Weighted-average remaining lease term (in years)
Current lease liabilities
Non-current lease liabilities
Right-of-use assets
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other deferred credits and noncurrent liabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other noncurrent assets
Kentucky Utilities Co [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	1 year
Kentucky Utilities Co [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	10 years