New Accounting Guidance Pending Adoption	3 Months Ended
Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	18. New Accounting Guidance Pending Adoption (All Registrants) Accounting for Leases In February 2016, the FASB issued accounting guidance for leases. This new guidance requires lessees to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). For income statement purposes, the FASB retained a dual model for lessees, requiring leases to be classified as either operating or finance. Operating leases will result in straight-line expense (similar to current operating leases) while finance leases will result in a front-loaded expense pattern (similar to current capital leases). Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright line tests. Lessor accounting under the new guidance is similar to the current model, but updated to align with certain changes to the lessee model and the new revenue recognition standard. Similar to current practice, lessors will classify leases as operating, direct financing, or sales-type. The standard is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition, and provides for certain practical expedients. One of these practical expedients allows entities to elect to (1) not reassess whether existing contracts contain leases, (2) carryforward the existing lease classification, and (3) not reassess initial direct costs associated with existing leases. In January 2018, the FASB also issued additional guidance that provides for a practical expedient that allows entities to elect to not evaluate land easements as leases that exist or expired before the adoption date and were not previously accounted for as leases under current lease guidance. The Registrants plan to elect these practical expedients. Transition will require application of the new guidance at the beginning of the earliest comparative period presented. The Registrants are currently assessing the impact of adopting this guidance. The Registrants will adopt this guidance effective January 1, 2019. Accounting for Financial Instrument Credit Losses In June 2016, the FASB issued accounting guidance that requires the use of a current expected credit loss (CECL) model for the measurement of credit losses on financial instruments within the scope of this guidance, which includes accounts receivable. The CECL model requires an entity to measure credit losses using historical information, current information and reasonable and supportable forecasts of future events, rather than the incurred loss impairment model required under current GAAP. For public business entities, this guidance will be applied using a modified retrospective approach and is effective for fiscal years beginning after December 15, 2019, and interim periods within those years. All entities may early adopt this guidance in beginning after December 15, 2018, including interim periods within those years. The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it. Improvements to Accounting for Hedging Activities In August 2017, the FASB issued accounting guidance that reduces complexity when applying hedge accounting as well as improves transparency about an entity's risk management activities. This guidance eliminates recognizing hedge ineffectiveness for cash flow and net investment hedges and provides for the ability to perform subsequent effectiveness assessments qualitatively. The guidance also makes certain changes to allowable methodologies such as allowing entities to apply the short-cut method to partial-term fair value hedges of interest rate risk as well as expands the ability to apply the critical terms match method to cash flow hedges of groups of forecasted transactions. The guidance also updates certain recognition and presentation requirements as well as disclosure requirements. For public business entities, this guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. This standard must be adopted using a modified retrospective approach and provides for certain transition elections that must be made prior to the first effectiveness testing date after adoption. The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it. (PPL, LKE, LG&E and KU) Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued accounting guidance that simplifies the test for goodwill impairment by eliminating the second step of the quantitative test. The second step of the quantitative test requires a calculation of the implied fair value of goodwill, which is determined in the same manner as the amount of goodwill in a business combination. Under this new guidance, an entity will now compare the estimated fair value of a reporting unit with its carrying value and recognize an impairment charge for the amount the carrying amount exceeds the fair value of the reporting unit. For public business entities, this guidance will be applied prospectively and is effective for annual or any interim goodwill impairment tests for fiscal years beginning after December 15, 2019. All entities may early adopt this guidance for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it. (PPL and LKE) Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the FASB issued accounting guidance that gives entities the option to reclassify tax effects stranded within AOCI as a result of the TCJA to retained earnings. The reclassification applies only to those stranded tax effects arising from the TCJA enactment. Certain disclosures related to the stranded tax effects, including a description of the accounting policy for releasing income tax effects from AOCI, are required. For all entities, this guidance is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption is permitted, including adoption in any interim period. The amendments should be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the TCJA is recognized. The adoption of this guidance will result in PPL and LKE reclassifying $50 million and $18 million of deferred tax effects (primarily related to pension and other post-retirement benefits) stranded in AOCI as a result of the TCJA to retained earnings. The Registrants are assessing the period in which they will adopt this guidance.

18. New Accounting Guidance Pending Adoption

(All Registrants)

Accounting for Leases

In February 2016, the FASB issued accounting guidance for leases. This new guidance requires lessees to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). For income statement purposes, the FASB retained a dual model for lessees, requiring leases to be classified as either operating or finance. Operating leases will result in straight-line expense (similar to current operating leases) while finance leases will result in a front-loaded expense pattern (similar to current capital leases). Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright line tests.

Lessor accounting under the new guidance is similar to the current model, but updated to align with certain changes to the lessee model and the new revenue recognition standard. Similar to current practice, lessors will classify leases as operating, direct financing, or sales-type.

The standard is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The new standard must be adopted using a modified retrospective transition, and provides for certain practical expedients. One of these practical expedients allows entities to elect to (1) not reassess whether existing contracts contain leases, (2) carryforward the existing lease classification, and (3) not reassess initial direct costs associated with existing leases. In January 2018, the FASB also issued additional guidance that provides for a practical expedient that allows entities to elect to not evaluate land easements as leases that exist or expired before the adoption date and were not previously accounted for as leases under current lease guidance. The Registrants plan to elect these practical expedients. Transition will require application of the new guidance at the beginning of the earliest comparative period presented.

The Registrants are currently assessing the impact of adopting this guidance. The Registrants will adopt this guidance effective January 1, 2019.

Accounting for Financial Instrument Credit Losses

In June 2016, the FASB issued accounting guidance that requires the use of a current expected credit loss (CECL) model for the measurement of credit losses on financial instruments within the scope of this guidance, which includes accounts receivable. The CECL model requires an entity to measure credit losses using historical information, current information and reasonable and supportable forecasts of future events, rather than the incurred loss impairment model required under current GAAP.

For public business entities, this guidance will be applied using a modified retrospective approach and is effective for fiscal years beginning after December 15, 2019, and interim periods within those years. All entities may early adopt this guidance in beginning after December 15, 2018, including interim periods within those years.

The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it.

Improvements to Accounting for Hedging Activities

In August 2017, the FASB issued accounting guidance that reduces complexity when applying hedge accounting as well as improves transparency about an entity's risk management activities. This guidance eliminates recognizing hedge ineffectiveness for cash flow and net investment hedges and provides for the ability to perform subsequent effectiveness assessments qualitatively. The guidance also makes certain changes to allowable methodologies such as allowing entities to apply the short-cut method to partial-term fair value hedges of interest rate risk as well as expands the ability to apply the critical terms match method to cash flow hedges of groups of forecasted transactions. The guidance also updates certain recognition and presentation requirements as well as disclosure requirements.

For public business entities, this guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. This standard must be adopted using a modified retrospective approach and provides for certain transition elections that must be made prior to the first effectiveness testing date after adoption.

The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it.

(PPL, LKE, LG&E and KU)

Simplifying the Test for Goodwill Impairment

In January 2017, the FASB issued accounting guidance that simplifies the test for goodwill impairment by eliminating the second step of the quantitative test. The second step of the quantitative test requires a calculation of the implied fair value of goodwill, which is determined in the same manner as the amount of goodwill in a business combination. Under this new guidance, an entity will now compare the estimated fair value of a reporting unit with its carrying value and recognize an impairment charge for the amount the carrying amount exceeds the fair value of the reporting unit.

For public business entities, this guidance will be applied prospectively and is effective for annual or any interim goodwill impairment tests for fiscal years beginning after December 15, 2019. All entities may early adopt this guidance for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017.

The Registrants are currently assessing the impact of adopting this guidance and the period they will adopt it.

(PPL and LKE)

Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income

In February 2018, the FASB issued accounting guidance that gives entities the option to reclassify tax effects stranded within AOCI as a result of the TCJA to retained earnings. The reclassification applies only to those stranded tax effects arising from the TCJA enactment. Certain disclosures related to the stranded tax effects, including a description of the accounting policy for releasing income tax effects from AOCI, are required.

For all entities, this guidance is effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption is permitted, including adoption in any interim period. The amendments should be applied either in the period of adoption or retrospectively to each period in which the effect of the change in the U.S. federal corporate income tax rate in the TCJA is recognized.

The adoption of this guidance will result in PPL and LKE reclassifying $50 million and $18 million of deferred tax effects (primarily related to pension and other post-retirement benefits) stranded in AOCI as a result of the TCJA to retained earnings. The Registrants are assessing the period in which they will adopt this guidance.