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Utility Rate Regulation (Regulatory Matters) (Details) $ in Millions |  |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jan. 29, 2018 USD ($) | Jan. 10, 2018 USD ($) | Jun. 23, 2017 | Jun. 30, 2017 USD ($) | May 31, 2017 USD ($) | Aug. 31, 2016 | Dec. 31, 2017 USD ($) Integer
Regulatory Matters - United Kingdom Activities - Ofgem Review of Line Loss Calculation (Numeric) [Abstract] |  |  |  |  |  |  |
Number Of Distribution Network Operators | Integer |  |  |  |  |  |  | 4
PPL Electric [Member] | Act 129 Compliance Rider [Member] |  |  |  |  |  |  |
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract] |  |  |  |  |  |  |
Minimum term of long term supply contract under Act 129 (in years) |  |  |  |  |  |  | 4 years
Maximum term of long term supply contract under Act 129 (in years) |  |  |  |  |  |  | 20 years
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129 |  |  |  |  |  |  | 25.00%
Maximum amount of costs that can be recovered under the Act 129 Phase III plan |  |  |  |  |  |  | $ 313
Period over which program costs can be recovered (in years) |  |  |  |  |  |  | 5 years
LKE [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Depreciation Rate Increase (Decrease) |  |  |  | $ 15 |  |  |
LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Return on equity for approved projects remaining from earlier ECR plans |  |  | 10.00% |  |  |  |
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings |  |  | 9.80% |  |  |  |
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects |  |  | 9.70% |  |  |  |
Return on equity |  |  |  |  |  |  | 9.70%
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 12 months
LGE [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 5.20% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 59 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 57 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 59 |  |
LGE [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 2.10% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 8 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 7 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 8 |  |
LGE [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | $ 69 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 69 |  |  |  |  |  |
LGE [Member] | Subsequent Event [Member] | Gas Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 17 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 17 |  |  |  |  |  |
LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service |  | $ 104 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service |  | 11 |  |  |  |  |
LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Gas Service |  | 62 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Gas Service |  | 3 |  |  |  |  |
KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Return on equity for approved projects remaining from earlier ECR plans |  |  | 10.00% |  |  |  |
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings |  |  | 9.80% |  |  |  |
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects |  |  | 9.70% |  |  |  |
Return on equity |  |  |  |  |  |  | 9.70%
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 12 months
KU [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 3.20% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 55 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 52 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 55 |  |
KU [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 91 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 91 |  |  |  |  |  |
KU [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service |  | 155 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service |  | 17 |  |  |  |  |
PPL Electric Utilities Corp [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 5 years
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract] |  |  |  |  |  |  |
Minimum term of long term supply contract under Act 129 (in years) |  |  |  |  |  |  | 4 years
Maximum term of long term supply contract under Act 129 (in years) |  |  |  |  |  |  | 20 years
Maximum percentage of long-term contracts that can be included in the mix of PLR supply contracts under Act 129 |  |  |  |  |  |  | 25.00%
Maximum amount of costs that can be recovered under the Act 129 Phase III plan |  |  |  |  |  |  | $ 313
Period over which program costs can be recovered (in years) |  |  |  |  |  |  | 5 years
PPL Electric Utilities Corp [Member] | Act 129 Compliance Rider [Member] |  |  |  |  |  |  |
Regulatory Matters - Pennsylvania Activities - Act 129 (Numeric) [Abstract] |  |  |  |  |  |  |
Maximum amount of costs that can be recovered under the Act 129 Phase III plan |  |  |  |  |  |  | $ 313
Period over which program costs can be recovered (in years) |  |  |  |  |  |  | 5 years
LG And E And KU Energy LLC [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Depreciation Rate Increase (Decrease) |  |  |  | $ 15 |  |  |
LG And E And KU Energy LLC [Member] | LGE [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Gas Franchise (Numeric) [Abstract] |  |  |  |  |  |  |
Franchise Agreement Term |  |  |  |  |  | 5 years |
Days of Notice to Modify Franchise Fee |  |  |  |  |  | 60 days |
Franchise Fee Cap |  |  |  |  |  | 3.00% |
Franchise Fee If Recovered From Customers |  |  |  |  |  | 0.00% |
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Return on equity for approved projects remaining from earlier ECR plans |  |  | 10.00% |  |  |  |
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings |  |  | 9.80% |  |  |  |
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects |  |  | 9.70% |  |  |  |
Return on equity |  |  |  |  |  |  | 9.70%
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 12 months
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 5.20% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 59 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 57 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 59 |  |
LG And E And KU Energy LLC [Member] | LGE [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 2.10% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 8 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 7 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 8 |  |
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 69 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 69 |  |  |  |  |  |
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Gas Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 17 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 17 |  |  |  |  |  |
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service |  | 104 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service |  | 11 |  |  |  |  |
LG And E And KU Energy LLC [Member] | LGE [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Gas Service |  | 62 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Gas Service |  | 3 |  |  |  |  |
LG And E And KU Energy LLC [Member] | KU [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Return on equity for approved projects remaining from earlier ECR plans |  |  | 10.00% |  |  |  |
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings |  |  | 9.80% |  |  |  |
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects |  |  | 9.70% |  |  |  |
Return on equity |  |  |  |  |  |  | 9.70%
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 12 months
LG And E And KU Energy LLC [Member] | KU [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 3.20% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 55 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 52 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 55 |  |
LG And E And KU Energy LLC [Member] | KU [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 91 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 91 |  |  |  |  |  |
LG And E And KU Energy LLC [Member] | KU [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service |  | 155 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service |  | 17 |  |  |  |  |
Louisville Gas And Electric Co [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Gas Franchise (Numeric) [Abstract] |  |  |  |  |  |  |
Franchise Agreement Term |  |  |  |  |  | 5 years |
Days of Notice to Modify Franchise Fee |  |  |  |  |  | 60 days |
Franchise Fee Cap |  |  |  |  |  | 3.00% |
Franchise Fee If Recovered From Customers |  |  |  |  |  | 0.00% |
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Return on equity for approved projects remaining from earlier ECR plans |  |  | 10.00% |  |  |  |
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings |  |  | 9.80% |  |  |  |
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects |  |  | 9.70% |  |  |  |
Return on equity |  |  |  |  |  |  | 9.70%
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 12 months
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 5.20% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 59 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 57 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 59 |  |
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 2.10% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 8 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 7 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 8 |  |
Louisville Gas And Electric Co [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Depreciation Rate Increase (Decrease) |  |  |  | $ 4 |  |  |
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 69 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 69 |  |  |  |  |  |
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Gas Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 17 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 17 |  |  |  |  |  |
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service |  | 104 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service |  | 11 |  |  |  |  |
Louisville Gas And Electric Co [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Gas Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Gas Service |  | 62 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Gas Service |  | 3 |  |  |  |  |
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Environmental Cost Recovery [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Return on equity for approved projects remaining from earlier ECR plans |  |  | 10.00% |  |  |  |
Return On Equity Approved Projects In 2016 Environmental Cost Recovery Proceedings |  |  | 9.80% |  |  |  |
Return On Equity For All Existing Approved Environmental Cost Recovery Plans And Projects |  |  | 9.70% |  |  |  |
Return on equity |  |  |  |  |  |  | 9.70%
Amortization period for the deferred recovery of a regulatory asset |  |  |  |  |  |  | 12 months
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Percentage |  |  |  | 3.20% |  |  |
Public Utilities Proposed Return On Equity Percentage |  |  |  |  | 9.75% |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 55 |  |
Increase in annual revenue requirements associated with base rates resulting from rate case |  |  |  | $ 52 |  |  |
Return on equity |  |  |  | 9.70% |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount |  |  |  |  | $ 55 |  |
Kentucky Utilities Co [Member] | Kentucky Public Service Commission [Member] | Depreciation Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities, Approved Depreciation Rate Increase (Decrease) |  |  |  | $ 11 |  |  |
Kentucky Utilities Co [Member] | Subsequent Event [Member] | Electric Rates [Member] | TCJA Savings Distributed To Customers [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - Rate Case Proceedings (Numeric) [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | 91 |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - TCJA Impact On LG&E And KU Rates [Abstract] |  |  |  |  |  |  |
Public Utilities Proposed Rate Increase Decrease Amount | $ 91 |  |  |  |  |  |
Kentucky Utilities Co [Member] | Subsequent Event [Member] | Kentucky Public Service Commission [Member] | Electric Rates [Member] |  |  |  |  |  |  |
Regulatory Matters - Kentucky Activities - CPCN Filings (Numeric) [Abstract] |  |  |  |  |  |  |
Advanced Metering Systems Deployment Estimated Capital Cost, Electric Service |  | 155 |  |  |  |  |
Advanced Metering Systems Deployment Incremental O&M Cost, Electric Service |  | $ 17 |  |  |  |  |

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- Definition The period over which Act 129 Phase III Plan costs will be recovered in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Minimum term of long-term contracts for PLR supply allowed under Act 129 in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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