New Accounting Guidance Pending Adoption New Accounting Guidance Pending Adoption (Details) - Forecast [Member] - Accounting Standards Update 2016-02 [Member] $ in Millions	Jan. 01, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	$ 80
Current Lease Liability	25
Noncurrent Lease Liability	65
LG And E And KU Energy LLC [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	55
Current Lease Liability	20
Noncurrent Lease Liability	45
Louisville Gas And Electric Co [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	25
Current Lease Liability	10
Noncurrent Lease Liability	15
Kentucky Utilities Co [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of Use Asset	30
Current Lease Liability	10
Noncurrent Lease Liability	$ 25