New Accounting Guidance Adopted (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019
Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	$ 96	$ 81
Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	26	23
Other Deferred Credits And Noncurrent Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Noncurrent	78	67
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	47	56
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	18
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	39	46
Louisville Gas And Electric Co [Member] | Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	18	23
Louisville Gas And Electric Co [Member] | Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	6	9
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	18
Kentucky Utilities Co [Member] | Other Noncurrent Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	28	31
Kentucky Utilities Co [Member] | Other Current Liabilities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Liability - Current	10	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	$ 23	$ 26