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REGULATORY ENVIRONMENT (Details) $ in Millions | 1 Months Ended | 3 Months Ended |
--- | --- | --- | ---
Mar. 31, 2019 USD ($) Assurance company | Dec. 31, 2018 USD ($) | Apr. 30, 2018 USD ($) | Mar. 31, 2018 USD ($) | Feb. 28, 2018 Filings | Nov. 30, 2017 USD ($) | Sep. 30, 2017 USD ($) utility | Mar. 31, 2019 USD ($) Assurance | Mar. 31, 2018 USD ($) | May 31, 2018 USD ($) solar_projects MW
Regulatory environment |  |  |  |  |  |  |  |  |  |
Capital investments related to gas utility infrastructure |  |  |  |  |  |  |  | $ 358.8 | $ 439.6 |
Operation and maintenance expenses related to gas utility infrastructure |  |  |  |  |  |  |  | 550.6 | $ 511.9 |
WE | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Electric rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 83.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 2.90% |  |  |  |  |  |  |  |  |
WE | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Natural gas rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 15.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 3.90% |  |  |  |  |  |  |  |  |
WE | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Steam rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 1.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 4.50% |  |  |  |  |  |  |  |  |
WE | Public Service Commission of Wisconsin (PSCW) | 2021 rates | Electric rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 83.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 2.90% |  |  |  |  |  |  |  |  |
WE | Public Service Commission of Wisconsin (PSCW) | 2020 and 2021 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested return on equity (as a percent) | 10.35% |  |  |  |  |  |  |  |  |
WE | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Approved return on equity (as a percent) |  |  |  |  |  |  | 10.20% |  |  |
Income statement impact of flow through of repair-related deferred tax liabilities |  |  |  |  |  |  |  | $ 0.0 |  |
WG | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Natural gas rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 11.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 1.80% |  |  |  |  |  |  |  |  |
WG | Public Service Commission of Wisconsin (PSCW) | 2020 and 2021 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested return on equity (as a percent) | 10.30% |  |  |  |  |  |  |  |  |
WG | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Approved return on equity (as a percent) |  |  |  |  |  |  | 10.30% |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | Badger Hollow Solar Farm and Two Creeks Solar Project |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Number of solar projects for which approval has been requested | solar_projects |  |  |  |  |  |  |  |  |  | 2
Total output of two solar projects owned by WPS (in megawatts) | MW |  |  |  |  |  |  |  |  |  | 200
WPS share of cost for certain solar projects |  |  |  |  |  |  |  |  |  | $ 260.0
WPS | Public Service Commission of Wisconsin (PSCW) | Two Creeks Solar Project |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Solar project output owned by WPS (in megawatts) | MW |  |  |  |  |  |  |  |  |  | 100
WPS | Public Service Commission of Wisconsin (PSCW) | Badger Hollow Solar Farm |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Solar project output owned by WPS (in megawatts) | MW |  |  |  |  |  |  |  |  |  | 100
WPS | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Electric rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 49.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 4.90% |  |  |  |  |  |  |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Natural gas rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 7.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 2.40% |  |  |  |  |  |  |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | 2021 rates | Electric rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 49.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 4.90% |  |  |  |  |  |  |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | 2021 rates | Natural gas rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested rate increase | $ 7.0 |  |  |  |  |  |  |  |  |
Requested rate increase (as a percent) | 2.40% |  |  |  |  |  |  |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | 2020 and 2021 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Requested return on equity (as a percent) | 10.35% |  |  |  |  |  |  |  |  |
WPS | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Approved return on equity (as a percent) |  |  |  |  |  |  | 10.00% |  |  |
Authorized revenue requirement for the ReACT project |  |  |  |  |  |  | $ 275.0 |  |  |
AFUDC |  |  |  |  |  |  | 51.0 |  |  |
Estimated cost of the ReACT project, excluding AFUDC |  |  |  |  |  |  | $ 342.0 |  |  |
WE, WG, and WPS | Public Service Commission of Wisconsin (PSCW) | 2020 and 2021 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Number of companies filing rate increase request | company | 3 |  |  |  |  |  |  |  |  |
Requested common equity component average (as a percent) | 52.00% |  |  |  |  |  |  |  |  |
WE, WG, and WPS | Public Service Commission of Wisconsin (PSCW) | 2018 and 2019 rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Number of utilities with earnings sharing mechanism | utility |  |  |  |  |  |  | 3 |  |  |
Percentage of first 50 basis points of additional utility earnings shared with customers |  |  |  |  |  |  | 50.00% |  |  |
Return on equity in excess of authorized amount (as a percent) |  |  |  |  |  |  | 0.50% |  |  |
PGL | Illinois Commerce Commission (ICC) |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Amount of assurance that PGL's QIP rider costs will be recoverable | Assurance | 0 |  |  |  |  |  |  | 0 |  |
MERC | Minnesota Public Utilities Commission (MPUC) | Gas utility infrastructure costs |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Capital investments related to gas utility infrastructure |  |  | $ 12.0 |  |  |  |  |  |  |
Operation and maintenance expenses related to gas utility infrastructure |  |  | $ 3.0 |  |  |  |  |  |  |
MERC | Minnesota Public Utilities Commission (MPUC) | 2018 rates | Natural gas rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Change in regulatory liabilities |  |  |  |  |  |  |  | $ 6.7 |  |
Approved return on equity (as a percent) |  | 9.70% |  |  |  |  |  |  |  |
Interim rate increase |  |  |  | $ 7.0 |  | $ 9.5 |  |  |  |
Interim rate increase (as a percent) |  |  |  | 2.81% |  | 3.78% |  |  |  |
Interim rate reduction |  |  |  | $ 2.5 |  |  |  |  |  |
Interim rates return on equity (as a percent) |  |  |  | 9.11% |  |  |  |  |  |
Interim rates common equity component average (as a percent) |  |  |  | 50.90% |  |  |  |  |  |
Approved rate increase |  | $ 3.1 |  |  |  |  |  |  |  |
Approved rate increase (as a percent) |  | 1.26% |  |  |  |  |  |  |  |
Approved common equity component average (as a percent) |  | 50.90% |  |  |  |  |  |  |  |
MGU and UMERC | Michigan Public Service Commission (MPSC) |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Number of filings required related to the Tax Cuts and Jobs Act of 2017 | Filings |  |  |  |  | 3 |  |  |  |  |
Tax Cuts and Jobs Act of 2017 | WE | Public Service Commission of Wisconsin (PSCW) | 2020 and 2021 rates | Electric rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Change in regulatory liabilities | $ 111.0 |  |  |  |  |  |  |  |  |
Tax Cuts and Jobs Act of 2017 | WPS | Public Service Commission of Wisconsin (PSCW) | 2020 rates | Natural gas rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Change in regulatory liabilities | 7.0 |  |  |  |  |  |  |  |  |
Tax Cuts and Jobs Act of 2017 | WPS | Public Service Commission of Wisconsin (PSCW) | 2020 and 2021 rates | Electric rates |  |  |  |  |  |  |  |  |  |
Regulatory environment |  |  |  |  |  |  |  |  |  |
Change in regulatory liabilities | $ 40.0 |  |  |  |  |  |  |  |  |

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