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Regulatory Environment - Tax Cuts and Jobs Act of 2017 (Details) $ in Millions | 1 Months Ended |
--- | --- | ---
May 31, 2018 | Feb. 28, 2018 Filings | Dec. 31, 2017 USD ($) | Dec. 31, 2019 customer
Public Utilities, General Disclosures [Line Items] |  |  |  |
Estimated tax benefit related to the remeasurement of deferred income taxes from tax legislation |  |  | $ 2,657 |
MPSC | WE |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Number of Electric Customers Served in Michigan | customer |  |  |  | 1
MPSC | MGU |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Number of filings required related to the Tax Cuts and Jobs Act of 2018 | Filings |  | 3 |  |
Tax Cuts and Jobs Act of 2017 | Utility operations |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Estimated tax benefit related to the remeasurement of deferred income taxes from tax legislation |  |  | $ 2,529 |
2018 and 2019 rates | Electric rates | Public Service Commission of Wisconsin (PSCW) | WE |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Percentage of current tax benefit from Tax Cuts and Jobs Act of 2017 to be used to reduce regulatory assets | 80.00% |  |  |
Percent of current tax benefit from Tax Cuts and Jobs Act of 2017 to be returned to customers via bill credits | 20.00% |  |  |
2018 and 2019 rates | Electric rates | Public Service Commission of Wisconsin (PSCW) | WPS |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Percentage of current tax benefit from Tax Cuts and Jobs Act of 2017 to be used to reduce regulatory assets | 40.00% |  |  |
Percent of current tax benefit from Tax Cuts and Jobs Act of 2017 to be returned to customers via bill credits | 60.00% |  |  |
2018 and 2019 rates | Natural gas rates | Public Service Commission of Wisconsin (PSCW) | WE, WG, and WPS |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |
Percent of current tax benefit from Tax Cuts and Jobs Act of 2017 to be returned to customers via bill credits | 100.00% |  |  |

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- Definition The increase (decrease) during the reporting period in the account that represents the temporary difference that results from Income or Loss that is recognized for accounting purposes but not for tax purposes and vice versa. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
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- Definition Number of filings required related to the Tax Cuts and Jobs Act of 2018, which will be used to describe how benefits under this Act will be refunded to customers + References No definition available. + Details
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