New Accounting Guidance Adopted (Details) $ in Millions	Dec. 31, 2020 USD ($)
Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	$ 87
Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	24
Other Deferred Credits And Noncurrent Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Noncurrent	70
LG And E And KU Energy LLC [Member] | Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	46
LG And E And KU Energy LLC [Member] | Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	16
LG And E And KU Energy LLC [Member] | Other Deferred Credits And Noncurrent Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Noncurrent	37
Louisville Gas And Electric Co [Member] | Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	17
Louisville Gas And Electric Co [Member] | Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	6
Louisville Gas And Electric Co [Member] | Other Deferred Credits And Noncurrent Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Noncurrent	15
Kentucky Utilities Co [Member] | Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	27
Kentucky Utilities Co [Member] | Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	9
Kentucky Utilities Co [Member] | Other Deferred Credits And Noncurrent Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Noncurrent	$ 21