New Accounting Guidance Pending Adoption	3 Months Ended
Mar. 31, 2017
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	17. New Accounting Guidance Pending Adoption (All Registrants) Accounting for Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (FASB) issued accounting guidance that establishes a comprehensive new model for the recognition of revenue from contracts with customers. This model is based on the core principle that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. For public business entities, this guidance can be applied using either a full retrospective or modified retrospective transition method, beginning in annual reporting periods after December 15, 2017 and interim periods within those years. The Registrants will adopt this guidance effective January 1, 2018. The Registrants have performed an assessment of a significant portion of their revenue under this new guidance to determine its effect on their current revenue recognition policies, and at this time they do not believe it will have a material impact. However, the Registrants will continue to monitor the development of industry specific application guidance which could have an impact on their assessments. The Registrants are currently assessing the disclosure requirements included in the standard, which will result in increased information being provided to enable the users of the financial statements to understand the nature, amount, timing and uncertainty of revenue arising from contracts with customers. The Registrants will determine the transition method they will apply after the industry specific application guidance is final and the implications of using either the full retrospective or modified retrospective transition methods are known. 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 lines. 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 companies 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. 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 and the period they will adopt it. 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 annual reporting periods 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. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March 2017, the FASB issued accounting guidance that changes the income statement presentation of net periodic benefit cost. This new guidance requires the service cost component to be disaggregated from other components of net benefit cost and presented in the same income statement line items as other employee compensation costs arising from services rendered during the period. The other components of net periodic benefits will be presented separately from the line items that include the service cost and outside of any subtotal of operating income. Only the service cost component is eligible for capitalization. For public business entities, the guidance on the presentation of the components of net periodic benefit costs will be applied retrospectively. The guidance that limits the capitalization to the service cost component of net periodic benefit costs will be applied prospectively. This guidance is effective for fiscal years beginning after December 15, 2017 and interim periods within those years. The Registrants are currently assessing the impact of adopting this guidance and will adopt this guidance effective January 1, 2018. (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.

17. New Accounting Guidance Pending Adoption

(All Registrants)

Accounting for Revenue from Contracts with Customers

In May 2014, the Financial Accounting Standards Board (FASB) issued accounting guidance that establishes a comprehensive new model for the recognition of revenue from contracts with customers. This model is based on the core principle that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.

For public business entities, this guidance can be applied using either a full retrospective or modified retrospective transition method, beginning in annual reporting periods after December 15, 2017 and interim periods within those years. The Registrants will adopt this guidance effective January 1, 2018.

The Registrants have performed an assessment of a significant portion of their revenue under this new guidance to determine its effect on their current revenue recognition policies, and at this time they do not believe it will have a material impact. However, the Registrants will continue to monitor the development of industry specific application guidance which could have an impact on their assessments. The Registrants are currently assessing the disclosure requirements included in the standard, which will result in increased information being provided to enable the users of the financial statements to understand the nature, amount, timing and uncertainty of revenue arising from contracts with customers. The Registrants will determine the transition method they will apply after the industry specific application guidance is final and the implications of using either the full retrospective or modified retrospective transition methods are known.

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 lines.

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 companies 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. 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 and the period they will adopt it.

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 annual reporting periods 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.

Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost

In March 2017, the FASB issued accounting guidance that changes the income statement presentation of net periodic benefit cost. This new guidance requires the service cost component to be disaggregated from other components of net benefit cost and presented in the same income statement line items as other employee compensation costs arising from services rendered during the period. The other components of net periodic benefits will be presented separately from the line items that include the service cost and outside of any subtotal of operating income. Only the service cost component is eligible for capitalization.

For public business entities, the guidance on the presentation of the components of net periodic benefit costs will be applied retrospectively. The guidance that limits the capitalization to the service cost component of net periodic benefit costs will be applied prospectively. This guidance is effective for fiscal years beginning after December 15, 2017 and interim periods within those years.

The Registrants are currently assessing the impact of adopting this guidance and will adopt this guidance effective January 1, 2018.

(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.