New Accounting Guidance Pending Adoption New Accounting Guidance Pending Adoption (Details) $ in Millions	Dec. 31, 2021 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current lease liabilities	$ 22
Non-current lease liabilities	47
Louisville Gas And Electric Co [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current lease liabilities	6
Non-current lease liabilities	12
Kentucky Utilities Co [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current lease liabilities	9
Non-current lease liabilities	$ 17