Utility Rate Regulation - Regulatory Matters (Details) - Kentucky Public Service Commission [Member] - Environmental Cost Recovery [Member] $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
LKE [Member]
Regulatory Matters [Line Items]
Public Utilities Expected Capital Costs To Comply	$ 405
LGE [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Requested Return on Equity, Percentage	9.725%
KU [Member]
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Requested Return on Equity, Percentage	9.725%
LG And E And KU Energy LLC [Member]
Regulatory Matters [Line Items]
Public Utilities Expected Capital Costs To Comply	$ 405
LG And E And KU Energy LLC [Member] | LGE [Member]
Regulatory Matters [Line Items]
Public Utilities Expected Capital Costs To Comply	$ 153
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Requested Return on Equity, Percentage	9.725%
LG And E And KU Energy LLC [Member] | KU [Member]
Regulatory Matters [Line Items]
Public Utilities Expected Capital Costs To Comply	$ 252
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Requested Return on Equity, Percentage	9.725%
Louisville Gas And Electric Co [Member]
Regulatory Matters [Line Items]
Public Utilities Expected Capital Costs To Comply	$ 153
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Requested Return on Equity, Percentage	9.725%
Kentucky Utilities Co [Member]
Regulatory Matters [Line Items]
Public Utilities Expected Capital Costs To Comply	$ 252
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]
Public Utilities, Requested Return on Equity, Percentage	9.725%