Utility Rate Regulation - Regulatory Matters (Details) - USD ($)
$ in Millions

3 Months Ended

6 Months Ended

7 Months Ended

12 Months Ended

60 Months Ended

Jun. 30, 2021

Apr. 19, 2021

Nov. 25, 2020

May 21, 2020

Jun. 30, 2021

Dec. 31, 2020

Jun. 30, 2022

May 31, 2026

Kentucky Public Service Commission [Member] | Electric and Gas Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 331

Public Utilities, Requested Bill Credit

$ 53

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 199

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 217

PPL Electric [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

11.18%

Proposed Return Of Equity From Complaint

8.00%

Amended Proposed Return On Equity From Complaint

8.50%

Regulatory Liability due to ROE Reserve, After Tax

$ 17

$ 7

LGE [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

RAR Rider post-retirement recovery period

10 years

Stay Out Commitment Period

4 years

Requested Billing Credit Period

1 year

LGE [Member] | Kentucky Public Service Commission [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.425%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.55%

LGE [Member] | Kentucky Public Service Commission [Member] | Forecast [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Return on Equity, Percentage

10.00%

LGE [Member] | Kentucky Public Service Commission [Member] | Electric and Gas Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Bill Credit

$ 41

LGE [Member] | Kentucky Public Service Commission [Member] | Electric Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 131

Public Utilities, Requested Rate Increase (Decrease), Percentage

11.60%

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 73

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 77

LGE [Member] | Kentucky Public Service Commission [Member] | Gas Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 30

Public Utilities, Requested Rate Increase (Decrease), Percentage

8.30%

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 20

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 24

LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery and Gas Line Tracker

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.35%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.35%

KU [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

RAR Rider post-retirement recovery period

10 years

Stay Out Commitment Period

4 years

Requested Billing Credit Period

1 year

KU [Member] | Kentucky Public Service Commission [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.425%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.55%

KU [Member] | Kentucky Public Service Commission [Member] | Forecast [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Return on Equity, Percentage

10.00%

KU [Member] | Kentucky Public Service Commission [Member] | Electric Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 170

Public Utilities, Requested Rate Increase (Decrease), Percentage

10.40%

Public Utilities, Requested Bill Credit

$ 12

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 106

$ 116

KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.35%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.35%

PPL Electric Utilities Corp [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

11.18%

Proposed Return Of Equity From Complaint

8.00%

Amended Proposed Return On Equity From Complaint

8.50%

Regulatory Liability due to ROE Reserve, After Tax

$ 17

PPL Electric Utilities Corp [Member] | PPL Electric [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Act 129 Recovery Period Under Phase IV Plan

5 years

Regulatory Liability due to ROE Reserve, After Tax

$ 36

$ 20

Louisville Gas And Electric Co [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

RAR Rider post-retirement recovery period

10 years

Stay Out Commitment Period

4 years

Requested Billing Credit Period

1 year

Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.425%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.55%

Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Forecast [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Return on Equity, Percentage

10.00%

Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Electric and Gas Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Bill Credit

$ 41

Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Electric Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 131

Public Utilities, Requested Rate Increase (Decrease), Percentage

11.60%

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 73

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 77

Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Gas Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 30

Public Utilities, Requested Rate Increase (Decrease), Percentage

8.30%

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 20

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 24

Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery and Gas Line Tracker

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.35%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.35%

Kentucky Utilities Co [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

RAR Rider post-retirement recovery period

10 years

Stay Out Commitment Period

4 years

Requested Billing Credit Period

1 year

Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.425%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.55%

Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Forecast [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Return on Equity, Percentage

10.00%

Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Electric Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 170

Public Utilities, Requested Rate Increase (Decrease), Percentage

10.40%

Public Utilities, Requested Bill Credit

$ 12

Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member]

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Return on Equity, Percentage

9.35%

Public Utilities, Requested Rate Increase (Decrease), Amended, Percentage

9.35%

KU [Member] | Kentucky Public Service Commission [Member] | Electric Rates

Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 106

$ 116